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1Lesson 25: Introduction to the Hard Drive
225.1 What is a hard drive?
3A hard disk drive is a high-volume, disk storage device holding a fixed, high-density, rigid media. The hard drive is factory-sealed to protect enclosed components, which contain a computer's most important files.
4 
5The rigid disks or platters inside a hard drive are known for their physical inflexibility, earning the device its "hard" drive name. 
6Hard disk drives are also referred to as fixed disk drives because it is unconventional to remove one from a system once it has been installed. For environments that necessitate the swapping of hard drives, removable hard drive bays are increasingly popular.
7Hard drives and floppy drives share many physical and operational characteristics. Despite their similarities, hard disk drives are more complex in design, provide greater speed of access to data, and have greater storage capacity.
8Hot Swappable Drive
9 
10A hot swappable drive is a drive that can be removed and replaced by another drive while the computer is still turned on. A hot swappable drives are useful if you want to access or store information or programs on another hot swappable drive. It can also be used as an emergency backup if the original drive fails. Hot swapping works by providing an enclosure for the drive on the motherboard so that the bus is not aware that a drive has been removed or a different drive has been inserted.
11Hard Drive Speeds 
12 
13The speed of a hard drive is how fast the data will be processed. A hard drive’s speed is measured in revolutions per minute (rpm). Common hard drive speeds are 5400 rpm, 7200 rpm, 10,000 rpm, and 15,000 rpm. Revolutions per minute refer to how fast the spindle turns the platters that hold data. A hard drive with a higher rpm means that it can retrieve data quicker from the platters than a hard drive with a lower rpm. The retrieval speed will be noticeable when accessing large files or many files at once but not when accessing small files. Note: A faster hard drive will cost more than a slower hard drive.
14 
15(../index.html)
16Chapter Menu
17  Chapter 8: Maintaining and Protecting Windows 
188.2 System Information and Windows Registry
198.2.1 System Information
20Windows includes a free tool called System Information. It provides users with details about the computer's hardware, its components, as well as software related information, such as drivers.
21 
22System Information can be accessed by entering MSINFO32 into the taskbar search box (Windows key + S), Command Prompt, or Run dialogue box (Windows key +R). System Information can also be accessed from the Start menu:
23	•	Navigate to Start → All Apps → Windows Administrative Tools → System Information.
248.2.2 Windows Registry
25The Registry's purpose is to store settings for a number of different variables like user accounts, fonts, displays and crucial system files. Because the settings are crucial to system performance, the Registry should ONLY be edited by persons who fully understand the Registry, its hives, and their associated values. Editing these files should be done as a last resort—an errant entry can cause the system to be completely inoperable.
26 Editor's Note
27In most cases any settings that can be modified in Windows are related to a registry setting. In other words, there is almost always a user-interface driven alternative to manually modifying a registry entry. 
28Before making any changes to the registry it is strongly recommended to perform a backup prior to making any changes by using the Registry Editor's Export command from the File menu.
29Registry Editor
30 
31The Registry Editor is an interface that enables users to edit the system's Registry. This utility is available with all Windows operating systems. The Registry is a large database that stores important information about the computer’s hardware, software, and users. This database should not be directly accessed by untrained users, but sometimes the need arises for a trained technician to modify one or more settings that are causing errors.
32To access the Registry Editor:
331.	The Registry Editor can be accessed by entering RegEdit into a Run dialogue (Windows key +R) and clicking OK. You may be prompted by User Account Control to allow permission.
34 
353.	Once opened, you will find that the Registry is actually a series of files, each one pertaining to a different aspect of the operating system. Each of these sections are known as hives.
364.	Using the left hand pane, click into a folder and its contents to expand the directory.
37 
385.	Use Ctrl + F to perform a search within the registry for the first available result. Hitting F3 will advance the search to the next match.
396.	Any changes to the registry are saved immediately and are typically evident upon the next computer reboot.
407.	Click the "X" in the upper-right corner to exit.
41Lesson 25: Introduction to the Hard Drive
4225.3 Hard Drive Components
43Three major hard disk drive components are contained within a hard disk assembly: disk platters, head actuator mechanism, and spindle motor.
44 
45Exterior to the hard disk assembly are the circuit board and, on the rear of the unit, a power connector and interface (controller) connector (Later lessons will feature hard drive jumpers and DIP switches). 
46Hard Disk Assembly
47 
48A Hard Disk Assembly (HDA) is another name for the collective core of drive components sealed within a hard drive. HDA also refers to the actual factory-sealed case. Within the hard disk assembly are the disk platters, head actuator assembly, and spindle motor. 
49•	Disk Platters
50Disk platters refer to the physical space, or media, on which data is stored. A hard drive typically has two to five disk platters. 
51 
52Platters are usually made of aluminum alloy, glass or ceramic material. Platters range from 2.5-inch and 3.5-inch to 5.25-inch in diameter and feature a hole in the center where they are mounted on a hub or spindle. Platters are double-sided and coated on each side with a thin film of magnetically-sensitive media.
53•	Head Actuator Assembly
54The head actuator assembly is composed of read/write heads, control arms that hold the heads, and voice coil actuators that help direct the heads accurately across the disk platters. The head actuator mechanism positions the control arms and read/write heads over a disk platter's surface. 
55â—¦	A control arm is a mechanical appendage that suspends a read/write head above the surface of a disk platter. The control arm, similar in appearance to the arm of a record player, moves according to instructions given to the entire head actuator assembly.
56â—¦	A read/write head is a U- or 
57V-shaped device made of electrically conductive material. Read/write heads are wrapped in wires that make the heads sensitive and responsive to the magnetic media of a platter. 
58Hard disk platters are double-sided. A separate read/write head can be designated for each side: a three-platter hard drive would have six read/write heads. To offer customers various storage capacities, manufacturers usually offer hard drive versions of "1 less" read/write head: a three-platter hard drive would have five read/write heads. Each read/write head is mounted on the end of a control arm. Of all the read/write heads, only one head is active at a time. Amazingly, a read/write head can hover as close as 2 to 15 microns above a disk's surface. In comparison, an ordinary particle of dust or smoke can easily measure 30 microns in size. Read/write heads are never supposed to come in physical contact with a platter's surface during operation. However, a head may rest or "dock" on specially designated portion of a hard disk's surfaces when the computer is turned off. 
59â—¦	A voice coil actuator moves by means of electromagnetic feedback sent from a fixed magnet. A voice coil uses the magnetic feedback to accurately position and adjust the attached read/write heads. Made up of an electromagnetic coil connected to the end of the head rack (the collective control arms), the voice coil is placed close to a stationary magnet. Since a voice coil actuator functions purely by electromagnetic force, there is zero physical contact between the coil and magnet. Instead, the electromagnetic coils are energized by the magnet's force. Depending on the instructions sent to the hard drive's logic boards, the magnet either attracts or repels the coils, which in turn moves the head rack and the corresponding heads. 
60	•	Spindle Motor
61A spindle motor, sometimes called a hub, is a motor and stem system that spins disk platters beneath their respective control heads. Multiple platters mounted on the spindle's stem are separated by disk spacers and spun together in unison. Platters are staggered in position and secured in place by clips. The hard disk drive spindle motor rotates platters at high speeds ranging from 4,800- to 15,000-RPM.
62 
63A spindle is always powered directly by electricity with no assistance from belts or gears. A spindle must spin smoothly, since bumps or vibrations could seriously disrupt reading and writing operations. A spindle motor receives instructions from a closed-loop feedback system designed to keep rotation speeds stable and constant. These instructions commonly originate from data written onto the disk platters themselves.
64Exterior Hard Drive Components
65 
66Hard Drive Circuit Board 
67A hard drive usually has one or more circuit boards connecting to the hard drive assembly's exterior. A hard drive's circuit board helps to regulate a drive's spindle movement, head actuator systems, internal circuitry and drive controller.
68Hard drives fail sometimes as a result of mechanical problems. Failures can also occur within a hard drive's logic boards. Consequently, a faulty hard drive can sometimes be repaired by replacing the damaged circuit board with a circuit board from the exact same model of hard drive. Replacing the drive's circuit board allows a technician to repair a drive without losing data from the platters. 
69Replacing a damaged circuit board makes it possible to re-establish access to a hard drive's contents. This should be considered an emergency measure and the drive should be replaced once data is retrieved. 
70Installing a completely new hard drive, means losing the data stored on the faulty drive.
71Hard drive logic boards are generally easy to install or replace, mounted with standard screw hardware into the case chassis.
72Hard Drive Cables and Connectors
73A hard drive typically has several connectors for communicating with a computer, receiving power, and grounding to a computer's chassis: interface connector, power connectors, grounding tab, and external ground.
74•	An interface connector (controller connector) transports data, instructions and command signals between the computer system and the hard drive. Often, the hard drive connector can be connected in a daisy chain or bus-type configuration.
75•	Power connectors are either Molex four-pin connectors or SATA connectors attached to a computer's power supply. Hard drives usually require between 5 and 12 volts of power. 
76•	A hard drive's grounding tab provides a secure ground connection between a hard disk drive and a computer's chassis. Usually, a hard drive is mounted directly to a computer's chassis and there is no need for additional grounding.
77•	If a hard drive is installed on non-conductive material, such as fiberglass or plastic, an external ground is required. Improper or a lack of grounding can lead to hard drive malfunctions, failure, or general hard drive errors. 
78Lesson 25: Introduction to the Hard Drive
7925.4 How Hard Drives Read Data
80Tracks and Sectors
81 
82Hard disk platters are magnetically organized into tracks and sectors. Tracks are the concentric "rings" arranged around the disk surface. Tracks are divided into 512-byte sections called sectors. The number and exact locations of the tracks and sectors on a hard drive are determined by the manufacturer before the hard drive ships and cannot be changed. 
83Cylinders
84 
85In addition to tracks and sectors, hard disks are organized by cylinders.
86A cylinder is the three dimensional combination of each track on each platter in a hard disk. To help you visualize this, imagine looking down at a hard disk and that each track on the lower platters is connected to the track directly above it. Since each track is connected to the one above and below, if you were to isolate one track and pull it upward, you would have a cylinder.
87Although tracks are not physically connected on hard disks, cylinders are logically used by some hard drives to organize and retrieve data. 
88The Cylinder Head Sector (CHS) method, for example, is used to locate data on a hard drive as follows:
89A.	Hard drive circuit board receives a request from the computer for data that is located on cylinder one, head 6, sector 1000. 
90B.	Hard disk locates cylinder one (the track has been identified but not the platter).
91C.	Hard disk locates read/write head 6 (the platter has been identified).
92D.	Head 6 retrieves the data from sector 1000 (the exact location on a track on platter 6 has been identified, and the data is found). 
93Clusters
94 
95The computer's operating system organizes the hard drive's sectors into logical units called clusters.  The exact number of clusters depends on the operating system used.  Unlike sectors and tracks, clusters can be changed by formatting a hard drive.
96Servos
97 
98To find data on a disk platter, a hard drive uses a guidance system called a servo. A servo surveys a disk platter and its components, then tells the hard drive assembly where the read/write heads are in relation to the disk platters.
99 Editor's Note
100The hard drive finds and reads data on disk platters using read/write heads to translate organizational data patterns into electromagnetic impulses. A separate read/write head is designated for each side of each platter in a hard disk.
101A four-platter hard drive with double-sided platters has 
102eight read/write heads
103During operation, the servo is able to give ongoing information about where the heads are, where the heads should be, and how the heads need to adjust.
104When the servo mechanism determines the position of the read/write heads and where the heads need to move, the servo mechanism sends a signal to the voice coil actuator.
105Voice Coil Actuators
106 
107Voice Coil Actuator
108A voice coil actuator consists of a fixed magnet and an electromagnet coil connected to the head rack. Based on the strength of incoming servo signals, the magnet emits an electromagnetic charge, energizing the voice coal actuator.
109Using the magnetic signals, the voice coil actuator physically moves a head rack and its control arms. Each control arm suspends a read/write head above a spinning platter. As a head floats over a platter, the head reads data as magnetic impulses. The read/write heads send this data to a computer's motherboard for processing. 
110When new data is requested, the servo mechanism again monitors and senses where the read/write heads are. The servo then measures how far the head needs to move in order to find the new information. The servo sends signals back to the voice coil actuator. 
111The voice coil actuator guides a control arm, and the control arm strategically positions its read/write head to a new location above a spinning disk platter. The read/write heads read the new information and send it to a computer's motherboard for processing. The process for writing data to a hard drive is the same, except that data is written rather than read.
112The reading and writing process repeats indefinitely as the read/write heads read and write data to a computer's hard drive.
113Lesson 25: Introduction to the Hard Drive
11425.5 Connecting a Hard Drive
115The hard disk assembly (HDA) is housed in a mounting chassis that is attached to the system chassis' drive brackets. The bottom of the HDA is attached to the logic board that contains the drive's control circuitry.
116Located at the rear of the circuit board, the hard disk drive has two connectors, a power connector, and interface (controller) connector. The hard drive connects to the motherboard, exchanging data via the interface (controller) connector. Electricity is supplied to the hard drive from the system's power supply via the power connector.
117Hard Drive Power Connector
118 
119As you learned in an earlier lesson, a cable from the power supply provides power to the hard drive.  With a Molex connector, the power cable's female plug connects with a 4-pin male interface at the rear of the hard drive.  The pin-outs (or wire scheme) are color-coded to identify the voltage carried by each wire.
120As with the floppy drive, the hard drive uses two different voltages. This is because different components in the hard drive require different amounts of electricity. The hard drive circuit board that hosts the logic chips is designed for low +5 volt power. The drive motors require more power, so they use +12 volts.
121Pin #	Signal	Wire Color
122Pin 1	+5v	Red
123Pin 2 	Ground	Black
124Pin 3 	Ground	Black
125Pin 4 	+12v	Yellow
126Large Power Connector Pin-outs
127SATA power connectors add an extra 3.3 volt connection and are hot-swappable. Due to Molex to SATA converters not having a +3.3 volt connection, some drive manufacturers are not adding +3.3 volt power. 
128Devices without the 3.3 volt power may not be hot-swappable. 
129 
130 
131Hard Drive Controller Connector
132 
133The hard drive exchanges data signals with the controller on the motherboard by means of a flat ribbon cable or a SATA cable.
134 
135The ribbon cable's pin-outs and cable width are dependent on the type of interface.
136Master-Slave Relationship
137 
138When you are using only two IDE devices on a computer, connect each one to its own IDE interface and set each one as master. When connecting two devices to one IDE drive interface, however, you will need to set one device as master and one as slave using jumpers. Refer to the documentation provided on the drive itself, in the manual provided, or check the manufacturer's web page for master / slave jumper configurations. 
139 
140Care and Maintenance of Hard Drives
141 
142Since hard drives are sealed, they require no internal cleaning. Nevertheless they still require regular maintenance, usually once a month, due to file fragmentation, viruses and even surface problems. Regular maintenance consists of defragging the hard drive and performing a surface scan that checks for bad sectors.
143DEFRAG or SCANDISK are Microsoft utilities that will perform the function of defragging your hard drive. Third party providers also make hard drive utilities for cleaning your hard drive. Be sure to verify that the hard drive tests are non-destructive to data before running them.
144When a file is deleted from the system, it is not actually erased off the hard drive. Only its name is removed from the file system's file tracking tables. The data can be retrieved with the right utilities unless that area of the hard drive is overwritten with a new file. It is possible to purchase a third party utility that will overwrite your hard drive by placing gibberish on it and thus making it difficult to find the files you originally deleted. The utilities can be set up to leave the operating system and all currently undeleted files in tact, or it can erase the entire hard drive.
145A less drastic step is to purchase a third party utility that will overwrite your hard drive by placing gibberish on it; thus making it difficult to find the files you originally deleted. Overwriting only those files in unoccupied areas allows you to leave the operating system and other files on your hard disk intact. 
146Continual care and maintenance on a regular basis of your hard drive will lead to better and faster system performance. Always consult the manufacturer's recommended guidelines for maintenance and cleaning procedures. If permitted, use only the recommended cleaning cartridges or disks. 
147Lesson 29: Introduction to Video Adapters
14829.1 Video Adapters
149The video adapter is an expansion board that plugs directly into a computer's main logic board. Current video cards typically have their own slot on the motherboard reserved exclusively for the video card. 
150 
151A video adapter (video card) translates digital data from the CPU into an analog format the video display monitor can use to display images.
152Because the video display monitor's circuitry is analog, the video adapter's job is to act as a liaison, translating and processing digital data into analog signals that the monitor can use to display the output data.
153PCI Express
154 
155Most video cards use the PCI Express (PCIe) slot(s) that have an even greater bandwidth interface to the motherboard than AGP video cards. PCIe also uses serial data transfer to allow for higher clockspeeds, and can simultaneously transfer data in both directions. 
156Scalable Link Interface
157 
158Scalable Link Interface (SLI), an nVidia technology, uses the PCIe architecture to allow video card and motherboard manufacturers to offer the ability to add two or four PCIe video cards in parallel in a single motherboard. This lets the video cards team up and power the graphics output together, ideally at twice the speed. The graphics cards and motherboard must support SLI, and the operating system must be 32 or 64bit Windows XP or Linux. Another similar product is ATI's Crossfire. 
159 
160Lesson 29: Introduction to Video Adapters
16129.1 Video Adapters
162The video adapter is an expansion board that plugs directly into a computer's main logic board. Current video cards typically have their own slot on the motherboard reserved exclusively for the video card. 
163 
164A video adapter (video card) translates digital data from the CPU into an analog format the video display monitor can use to display images.
165Because the video display monitor's circuitry is analog, the video adapter's job is to act as a liaison, translating and processing digital data into analog signals that the monitor can use to display the output data.
166PCI Express
167 
168Most video cards use the PCI Express (PCIe) slot(s) that have an even greater bandwidth interface to the motherboard than AGP video cards. PCIe also uses serial data transfer to allow for higher clockspeeds, and can simultaneously transfer data in both directions. 
169Scalable Link Interface
170 
171Scalable Link Interface (SLI), an nVidia technology, uses the PCIe architecture to allow video card and motherboard manufacturers to offer the ability to add two or four PCIe video cards in parallel in a single motherboard. This lets the video cards team up and power the graphics output together, ideally at twice the speed. The graphics cards and motherboard must support SLI, and the operating system must be 32 or 64bit Windows XP or Linux. Another similar product is ATI's Crossfire. 
172 
173Lesson 29: Introduction to Video Adapters
17429.3 Pixels and Resolution
175The displayed image you finally see "onscreen" when the four video card components—video chip set, video memory, video BIOS, and RAMDAC—have concluded their work is an image made up of pixels and defined by resolution.
176The basic element of every video image is a pixel (dot). Hundreds of thousands to millions of pixels comprise what you see displayed on a video monitor. Every dot has a location reserved in video memory. 
177The maximum number of dots which can be displayed relates to the resolution. 
178The onscreen image's resolution is its degree of sharpness.
179Resolution 
180 
181Resolution is commonly expressed as a pair of numbers. Each pair of numbers represents the maximum possible number of dots on a horizontal axis and the maximum possible number dots on a vertical axis. 
182Basic VGA 640 X 480 resolution means that there are 640 possible dots on each line displayed on the screen's horizontal axis and 480 possible lines composed of dots on the vertical axis. A resolution of 640 x 480 shows 307,200 pixels on the screen. XGA expanded upon VGA by supporting two additional resolutions that improved color greatly:
183•	800 x 600 pixels (65,536 colors) 
184•	1024 x 768 pixels (palette of 256 colors) 
185Although Super Video Graphics Array (SVGA) was originally intended as another VGA extension, it evolved into a separate standard. SVGA generally refers to a resolution of 800 x 600 pixels but it can refer to a resolution of 1024 x 768 pixels.
186Ultra eXtended Graphics Array (UXGA) is being utilized for fullscreen monitors with its resolution of 1600 x 1200 pixels, making it four times the resolution of SVGA. For smaller displays (most commonly used on 1415 inch LCD laptop screens) SXGA+ has a resolution of 1400 x 1050 pixels.
187Available in high end LCD televisions and computer monitors, Widescreen Ultra eXtended Graphics Array (WUXGA) offers a display resolution of 1920 x 1200 pixels (showing 2,304,000 pixels on screen) with a 16:10 aspect ratio. 
188 
189 Editor's Note
190SVGA has a resolution of 800 by 600 pixels. XGA has a resolution of 1024 by 768 pixels. The higher the resolution, the sharper and clearer the image will be. Also, the higher the resolution, the more memory is required to draw an image. 
191 
192WQXGA (2560 x 1600) was first introduced in 2010 for home theater projectors. In 2012 Google introduced their Nexus tablet featuring WQXGA resolution, which at the time, the highest resolution available was the Apple iPad 3's QXGA (2048 x 1536). Many manufacturers produce monitors capable of WQXGA in 27-30 inch. WQXGA requires more bandwidth than one DVI can provide, therefore dual-link capable cables and devices are necessary. 
193 
194WQUXGA (3840x2400), the maximum resolution supported by DisplayPort 1.0, may require multiple DVI connectors either from the same graphics card, different graphics cards, or even different computers.
195Color Depth
196 
197When an image is displayed in color (or grayscale), a certain number of bits must be assigned per dot (per pixel) to achieve a given color depth or possible number of colors. The more bits that are assigned for each pixel increases the quantity of colors that it can display. The number of colors that each pixel can display is known as color depth.
198Bits per Pixel	Color Depth per Pixel - Known as: 
1994 bits 	16 colors - Standard VGA
2008 bits 	256 colors - Super VGA
20116 bits 	65,536 colors - High Color
20224 bits 	16,777,216 colors - True Color
20330/36/48 bits 	One Billion + colors - Deep Color
204Bits for Color Depth
205Apple's Retina Display
206 
207Apple uses the Retina Display brand name for screens that possess a pixel density that is high enough so the human eye is not able to detect individual pixels from abnormal viewing distance. Products that utilize the Retina display include the iPad Air, iPhone, iPod Touch, iPad, iPad Mini and MacBook Pro. The Retina quality can differ depending on the size of the display. Higher pixels per inch (PPI) for smaller displays and lower PPI for larger displays: 326 PPI for the smallest devices, 264 PPI for mid-sized devices and 220 PPI for larger devices. With a Retina display, each user interface widget is doubled in width and height to make up for the smaller pixels and this mode is referred to HiDPI mode. With a Retina display, pixels-per-degree (PPD) takes into consideration the screen resolution and the distance from which the device is observed. 
208The onset for a Retina display begins at the PPD value of 53 PPD. The PPD parameter is not an absolute parameter of the display like the pixel resolution. PPD depends on the distance between the display and the eye of the person looking at the display. If the eye moves closer to the display, the PPD will decline. 
209Likewise, if the eye moves away from the display, the PPD is increased proportionately to the distance.
210Lesson 29: Introduction to Video Adapters
21129.4 The Evolution of Video Adapters
212Video cards are a good watermark for charting the evolution of computers. Video displays are what people remember the most about computers. In the 1980s the Atari game system burst on the scene with color, low-resolution graphics, but it was quickly superseded in popularity by the Commodore 64 and Apple computers, which had better, higher resolution graphics. Since then video adapter design reflects the cutting edge graphics solutions from one year to the next.
213This lesson will outline this evolution and explain the technology behind it.
2141981
215 
216IBM, a company whose name is synonymous with personal computers, was first on the scene with the monochrome display adapter and (later that year) color graphics adapter (MDA and CGA respectively).
217As its name implies, the MDA was a black-and-white adapter that boasted a resolution of 720x350. Besides being limited to black and white, the MDA also could not display graphics. The MDA was adequate for its needs, which were primarily word-processing and other basic office applications.
218The CGA adapter, also released in 1981 was a step up from the MDA because it offered users more flexibility. Besides giving users a maximum of four colors (16 were available, but only four could be used at a time), the CGA adapter also gave users the option of working in either alphanumeric (A/N) or all points addressable (APA) mode for graphics. Regardless of which mode was chosen, the CGA adapter and its maximum resolution of 640x200 (when using two colors) or 320x200 (when using four colors) still left a lot to be desired when compared with today's adapters.
2191984
220 
221In 1984 IBM introduced the Enhanced Graphics Adapter (EGA). Despite its high cost, these adapters proved to be a nice improvement over the CGA. Most notably, the EGA was capable of displaying 16 colors at once and producing a maximum resolution of 640x350 pixels. The EGA adapter was also very flexible, for example it could be used with older monochrome monitors, or newer monitors, capable of taking advantage of the card's enhanced capabilities. It could also be upgraded to recognize up to 1,024 characters, as opposed to the CGA's 256 character ceiling. 
222Although this was a nice improvement, there was still a lot to be desired. Backward compatibility with software and hardware was imperfect and required constant tweaking. EGA's high price magnified this shortcoming, prompting a lot of users to stick with their older CGA adapters.
223The Professional Graphics Adapter (PGA) was also a 1984 release and was designed to accommodate the graphics needs of engineers. At the time of its release, the PGA cost as much as a car (about $5,000), which explains why it never really became popular. Despite its lack of popularity, the PGA made a significant contribution to the video adapter: the PGA was the first adapter to feature its own processor. This advancement gave the PGA the ability to display animation.
2241987
225 
226Between 1984 and 1987, video adapters made significant strides in both quality and cost. The most significant improvement was the Video Graphics Array (VGA), developed by IBM. The VGA was far more popular than any other previously released video adapter. In fact, IBM released two other video adapters in 1987: the 8514/A and the multi-color graphics array (MCGA), which were quickly discarded when it became apparent how much more popular the VGA was. VGA adapters are capable of displaying 256 colors at a resolution of 320x200 pixels, or 16 colors at a resolution of 640x480 pixels.
227VGA was the last video standard to garner industry-wide acceptance. VGA's color and resolution specifications became the video industry's common denominator. This meant that all subsequent video adapters were designed to support VGA's specifications. VGA has support in BIOS, eliminating the need for drivers (they are part of the BIOS). However, video cards released after VGA (including all modern video cards) require proprietary drivers to access the card's specific enhanced features. 
228 Editor's Note
229The video game industry is generally the driving force behind improving graphic capabilities in computers. The video card industry has reaped the benefits of increased consumer demand for games with detailed, high-resolution graphics. Look for continuing growth in the video card industry to coincide with the popularity of video games.
2301990s
231 
232The 1990s marked the modern age of computing (of course this watermark changes every five to 10 years) and there was no better piece of hardware to represent this than IBM's XGA display adapter. The newest link in a chain of video enhancements, the XGA was built from VGA technology and boasted 32-bit bus mastering. Bus-mastering, a new technology in 1990, gave the XGA the ability to process graphic demands without having to go through the computer's CPU.
233Besides bus-mastering, the XGA adapter was capable of more colors at higher resolutions than any preceding card. The XGA could display up to 65,536 colors at a resolution of 640x480 or 256 colors at a resolution of 1,024x768.
234Despite these improvements, XGA and XGA-2 (1992) were not popular because they were very proprietary technologies and didn't mesh well with products designed by other companies.
235The success behind the SVGA is its flexible nature. SVGA was not designed by IBM, but rather by independent manufacturers, trying to create a better quality, universally accepted video adapter. SVGA does not refer to a specific video card or video card specifications, but rather to many different kinds of video cards that offer a range of colors and resolutions. Despite their differences, both SVGA and VGA adapters use the same DB-15 connector.
236and Beyond
237 
238Improvements in video cards during this decade primarily focused on improving 3D algorithms and clock speeds. Two companies have emerged as rivals in this market: ATI and Nvidia. To render enhanced 3D graphics, both have developed specialized graphics processing units (GPUs) that are embedded in CPUs. 
239Modern computers can have a GPU on its video card or on the motherboard.
240Gaming demands have largely driven the market for high level graphics and performance. Early in the decade ATI introduced its Radeon products that supply graphics for Nintendo (GameCube and Wii) and Microsoft’s Xbox 360. Nvidia’s product lines include GeForce, used in a number of gaming applications.
241 
242Nvidia was the first to launch DirectX 10 video cards in late 2006, based on Compute Unified Device Architecture (Cuda); these cards were the GeForce 8800GTS and GeForce 8800GTX.  The CUDA line grew to include the GeForce 9 series and eventually to the GeForce 200 series (the flagship card being the powerful dual GPU card GTX 295 that was launched in early 2009).  The GeForce 200 series includes physically huge cards with even greater performance over the previous 8 and 9 series lines. All of these cards support Nvidias Scalable Link Interface (SLI) technology, allowing multiples of the same card to be run in one system to enhance performance.
243ATI released their first DirectX 10 cards shortly after Nvidia with its Radeon series, the most powerful card being the Radeon HD 3870.  To match the Nvidia GeForce 200 series ATI launched the Radeon HD 4000 series.  In late 2009 ATI stepped out ahead of Nvidia by releasing the first set of DirectX 11 video cards with the highest performing single GPU card being the Radeon HD 5890.  ATI released another powerhouse with its Radeon HD 5970, which is the first dual GPU DirectX 11 card and is easily the company’s flagship card.   These cards are massive in size and support ATI's CrossfireX technology, allowing for multiples of the same card to be run in one system to enhance performance.
244Lesson 33: Printers
24533.1 What is a printer?
246A printer is an output device that makes it possible to transfer the work you've done on a computer into a physically tangible, transportable form: hard copy. The hard copy obtains your work through a process known as ink dispersion. Simply stated, this is the process by which ink particles are distributed or dispersed evenly onto paper and heated to recreate an image or text.
247Printers are also classified by the following characteristics:
248Impact and Non-Impact
249 
250Printers produce images by using either impact or non-impact methods. 
251An impact printer uses a mechanical device to physically transfer or force an image on to paper. The term 
252"impact" describes the physical activity that occurs between a printer and paper during the printing process. This makes impact printers much noisier than their non-impact counterparts. Impact printers are still used by some business to produce invoices and credit card receipts.
253The print heads from an impact printer strike an inked ribbon, which triggers the characters to be imprinted on the paper. Impact printers utilize continuous-feed paper, which is also referred to as a tractor feed. Perforations are used to separate one sheet of paper from the next. The perforated strips on the side are utilized to feed the paper and to avoid skewing or shifting. Sheet feeders which print one page at a time can be used on some higher quality printers. A large roller, called a platen, applies pressure to keep the paper from slipping. When using a multiple-copy paper, you can adjust the platen gap to correspond to the thickness of the paper. 
254Unlike impact printers, non-impact printers are able to transfer an image without physically touching the paper. Some examples of non-impact printers include laser, inkjet, solid ink, thermal wax transfer and dye sublimation. Offering better quality and faster printing, non-impact printers are more common for typical users.
255All-in-One
256 
257All-in-one printers (sometimes referred to as multifunction printers) are printers that offer a combination of printing, copying, scanning, and faxing capabilities. The advantage of using an all-in-one printer is that it takes up less space and is typically less expensive than purchasing multiple machines.
258 
259All-in-ones do have their drawbacks however. You may have to compromise one function in favor of another. While one device may offer a higher print quality, it may not be the best choice when you need to scan an image. Additionally, you may not be able to use all functions at the same time. If you are printing an image, you won’t be able to send a fax.  
260Nevertheless, all-in-one printers offer a great option for users who want to maximize desk space and increase their work efficiency.
261Speed
262 
263The speed of some older printers is measured in characters per second. Newer printers are measured in pages per minute. Primarily used as a marketing tool, the speed of a printer can vary greatly depending on what is actually being printed. For instance, pages containing a large amount of graphics or photos typically take a longer time to print compared to pages with only text. In addition, full color pages will take longer than black and white pages.
264Monochrome and Color
265 
266Monochrome printers, as their name implies, can only produce an image consisting of one color, typically black.
267Color printers are widely available and work the same as monochrome printers, except they use for different colors: cyan, magenta, yellow, and key (black). By combining these primary colors together in various proportions, color printers are able to output the total range of colors and shades we normally see.
268Lesson 33: Printers
26933.2 Modern Printers
270Today, most printers use non-impact technology. Of the variety of non-impact printers currently on the market, two popular types are inkjet and laser printers.
271Inkjet Printer
272 
273Commonly used as a lower cost alternative to laser printers, an inkjet printer (also called a bubble jet) creates characters and graphics by spraying ink onto a page.
274Inside an inkjet printer, specialized ink cartridges are set into carriers atop the print head and are made up of a series of small electrically heated nozzles. When sufficiently heated, the ink "bubbles" and bursts through the nozzles, resulting in dots on paper. Magnetic plates in the ink path direct the ink onto the paper to form characters.
275 
276 Editor's Note
277Some cartridges have the print head incorporated within the unit. The additional parts required generally make these cartridges more expensive.  Associated printers, however, tend to be cheaper since they don't include the print head. Alternatively, cartridges without print heads can cost less, but the printers may be somewhat more expensive.
278As with dot matrix printers, the density of the dots in the characters helps determine the quality of the print. The quality of an inkjet’s output is also determined by the amount of ink used.  Today’s inkjets are able to produce photo-quality images with resolutions between 1200 to 4800 dots per inch (dpi), depending on the model.
279Advantages	Disadvantages
280	
281Advantages	Disadvantages
282Price: When compared in price, inkjet printers present a quality, affordable laser printer alternative. 
283Quality: Inkjet printers offer a high quality output, in some cases surpassing laser printer quality. Inkjet printers greatly exceed dot matrix printers in their versatility and font selection. 	Speed: Inkjet printers are very slow compared to dot matrix and laser printers.
284Mess: Fresh ink tends to smudge on anything other than high quality paper and can take a long time to dry.
285Operation Cost – Although less expensive to purchase than laser printers, inkjet printers cost more to operate due to their high ink usage.
286Advantages and Disadvantages of Inkjet Printers
287 
288Inkjet printers use the following printing process:
2891.	Cut-sheet paper feeds into the paper channel from a paper tray in the front or rear of the printer.
2902.	The paper is pulled into the paper path by an arm and is friction-fed between rollers over a platen and under the print head path.
2913.	The print head moves across the paper on a rail to spray the ink in the desired pattern.
2924.	The hard copy comes out at the front into another tray. 
293Laser Printers
294 
295A laser printer is a common and popular printer type that uses a laser and electro-photographic technology to transfer images to paper. Laser printers are also known as page printers or electronic printers. 
296Commonly used in homes and business, laser printers' extremely sharp images are ideal for creating highquality presentations. Color laser printers offer superior quality print-outs, and are available with up to fourcolor toners.
297Advantages	Disadvantages
298High speed: Laser printers function at high speed, typically much faster than inkjet printers.
299Versatility: Laser printers are ideal for a variety of tasks: page printing, envelopes, double-sided printing, and other demanding jobs. Also, color laser printers make it possible to recreate excellent quality transparencies and other color presentations.
300Networking Capability: Laser printers are ideal for businesses which require network settings and multiple workstations.
301Quality: Laser printers excel in printing detailed text documents including those with small fonts. 	RAM expense: Laser printers print whole pages from memory, so complex print jobs require large amounts of RAM. Unlike computer memory which is relatively cheap, printer memory is usually proprietary and expensive.
302Supply expense: Toner and other replacement parts such as a developer unit and fuser are expensive, though they don’t need to be changed as often as inkjet cartridges.
303Price: Laser printers are generally more expensive than inkjet printers. 
304Advantages and Disadvantages of Laser Printers
305 
306In order to understand how a laser printer works, and how to troubleshoot a laser printer, it is important to be familiar with the laser printer's primary components:
307•	The laser printer's photosensitive drum is the most integral part of the printer because it is involved with nearly every stage of the printing process. The job of the photosensitive drum is to store a high negative electrical charge that attracts toner as the laser printer progresses through its seven-step process. Toner is then attracted to the drum by this charge and transferred onto the paper.
308•	The transfer corona wire does what its name implies: transfers toner from the electrically charged drum to the paper. The transfer wire carries a positive charge that attracts toner off the drum and onto the paper.
309•	During the writing stage, the primary corona wire carries a -1000v charge which is evenly applied across the photosensitive drum, preparing the drum to be written on.
310•	The cleaning blade resembles a windshield wiper and works in much the same way. At the beginning of the printing cycle, the cleaning blade removes any residual toner from the drum.
311•	Toner is a fine powder which carries a negative charge equal to the charge carried by the photosensitive drum that has been charged by the primary corona wire. It is drawn to the photosensitive drum during the developing stage of the printing process. Excess toner, left on the drum after a print cycle ends, is swept off the drum by the cleaning blade. 
312•	Two fuser rollers work together to finalize the laser print production. Toner, attracted from the drum to the paper, needs to be melted, or fused into place. The fusing rollers, which also push the paper out of the printer, fuse the toner powder onto the paper by melting it with intense heat and pressure. The top roller applies heat, while the bottom roller applies pressure. 
313How Laser Printers Work
314 
315Laser printers are the fastest printer type: some versions can print 4 to 32 full pages in less than 1 minute. 
316Laser printers can also create two-sided printouts, envelopes, and transparencies. 
317To fulfill print requests, a laser printer must first complete a unique seven-step process. The seven steps are integral computer technician information:
318 
3191.	Cleaning - First a laser printer cleans the printer drum. Inside a laser printer, a soft cleaning blade removes loose toner from the drum mechanism, preparing the drum for a print job.
3202.	Erasing - The photosensitive drum is exposed to a uniform light which erases the image that was written onto the drum.
3213.	Conditioning - Prior to printing, an electric charge is transferred to the drum from the corona wire as the drum rotates beneath the wire. The printer charges the printing drum with a negative, high voltage charge. This process is referred to as "preconditioning exposure," or simply, "conditioning." 
3224.	Writing - The printer then exposes the charged drum to a scanning laser. The laser drains electricity off of the drum, creating an image on the drum's surface having a negative charge that is much lower than the surrounding area. This process is referred to as a "scanning exposure."
3235.	Developing - Toner is then exposed to the printer's drum. Due to the high negative energy nature of toner, it is attracted to areas of the drum with low negative energy (such as the laser touched areas). This process causes toner to move from the cartridge to the drum.
3246.	Transferring - As the drum rotates, the paper and drum move in unison. A second corona wire gives a sheet of paper a positive charge. As contact occurs between a drum and paper, the negatively charged toner is attracted to the positively charged paper. 
3257.	Fusing - Finally, the paper is passed through heated rollers where pressure and heat fuse the toner to the paper's surface. 
326 Editor's Note
327The industry exam may only cover six steps for laser printing. The industry exam combines step 1 and 2 into one step called "cleaning," even though they are distinct phases.
328
329Lesson 33: Printers
33033.3 Legacy Printers
331The following printers are either considered legacy, or are limited to specific applications.
332 
333Once common for home and small office use, a dot matrix uses a pin and ribbon system that forms dots on paper.  
334The process begins when a dot matrix printer receives data from a computer, directing the printer to go to work. Specialized mechanisms inside dot matrix printers strike pins against an ink ribbon, transferring tiny dots to paper. 
335 Editor's Note
336On dot matrix printers, print that is too light or has uneven levels of darkness usually indicates that the ribbon is worn out.
337 
338Separately, these ink dots are small, round, black points on a paper. Together, however, the dots' strategic location in close relation to one another forms images, characters and shapes. When dealing with a dot matrix printer, the printed document's quality depends largely on how closely the dots are placed together. 
339The dots' proximity depends on the number of pins in a print head. 
340Earlier dot matrix printers have only 9 pins in their print heads and produced Draft Quality prints. Eventually, dot matrix printers were able to produce Near Letter Quality (NLQ) prints. Some dot matrix printers have 24 pins that produce Near Letter Quality or Letter Quality (LQ) prints. 
341Today, dot matrix have been relegated mostly to high-volume, low quality production printouts such as cash register receipts and invoices.
342Advantages	Disadvantages
343Impact capabilities: A dot matrix printer's impact design allows the machine to print multi-part forms: a critical function for organizations that require multiple copies of printed material.
344Inexpensive operation: Dot matrix printers are cheaper to operate than laser or inkjet printers: maintenance is less costly, and ribbons are less expensive than the toner and ink required by laser or inkjet printers.	Quality: The main disadvantage of dot matrix printers is they are unsuitable for high quality presentations.
345Noise: Dot-matrix printers can be very loud due to the physical force of the printer. 
346Advantages and Disadvantages of Dot Matrix Printers
347Line Printers
348 
349A line printer, like the name implies, contains a chain of characters or pins that print an entire line at one time. Considered the fastest of the impact printers, line printers were able to print as many as 3,000 lines per minute. A major drawback for line printers was their low quality and inability to print graphics. Although used by some businesses for bulk printing, line printers were never used with personal computers. They have since been replaced by laser printers.
350Daisy Wheel Printers
351 
352The daisy wheel printer is a type of impact printer that used the same principle as a ball-head typewriter. The “daisy wheel” refers to a metal or plastic disk within the printer that contained characters which would stand out in relief along the outer edge. To print a character, the printer would rotate the wheel until the desired letter faced the paper. A hammer would then strike the disk forcing the character to hit the ink ribbon and would then leave an impression of the character on the page. Like line printers, daisy wheel printers were unable to print graphics and were replaced by dot matrix printers.
353Lesson 33: Printers
35433.4 Other Printer Types
355Although less common, following are some other types of printers and print technologies that are still available: 
356Solid Ink Laser Printers
357 
358Solid ink printers are a color, laser-class printer that first melts the wax based inks into a liquid, squirts or ‘jets’ the liquid onto a drum then applied to the paper. 
359 
360A very vivid registration of color is produced by solid ink printers due to the fact that the drum is more tightly controlled then the moving paper. These cost effective printers provide good quality printing on a variety of media. Advantages to this printer type are its simplicity of printing process, outstanding reliability requires few consumables and easy to setup and operate. Solid ink printer is also known as phase-change printer.
361Dye Sublimation Printers
362 
363This printer contains a roll of transparent film, comprised of page-size color panels that use high heat to transfer the colors one at a time to the paper. Dye sublimation printers are best known for smooth color transitions that produce photo lab quality images.
364Thermal or Thermal Hot Wax Printers
365 
366Thermal or thermal hot wax printers form an image by melting wax that cools and becomes permanent then adheres onto a heat-sensitive paper. These printers produce good quality though not quite photo-realistic images since the images are printed as dots and therefore must be dithered first.
367Whether one line of print or a full page is transferred, these printers utilize an equivalent panel of ink for each page to be printed. Monochrome printers have a black page for each page to be printed while their color counter parts have either three or four colored panels for each page. These printers are used in some older fax machines and cash registers.
368Thermal paper has a waxy quality that has been chemically preserved and becomes black when heated. Once a roll of thermal paper is loaded, the feed assembly moves the paper across the printer. Next, the electrical current is sent to the heating element found in the print head to produce heat. The heated areas of the print head create the pattern on the paper.
369An advantage to using a thermal printer is that it operates more quietly compared to other printers such as a dot matrix. Additionally, since they contain only a few moving parts, thermal printers tend to have a long life. Finally, unlike other inkjet and laser printers, there is no cost for ink or toner. However, thermal printers do have their disadvantages. Thermal printer paper is more expensive, must be kept at room temperature, and has a short shelf life. As far as print quality, thermal printers are unable to print high quality images. 
370Lastly, there is no option to print in color.
371Plotters
372 
373A plotter is a specialized printer that is neither a non-impact nor an impact printer. Plotters fall into their own unique category of printing devices. The earliest computer device for printing pictures and full-size engineering and architectural drawings was the plotter.
374 
375Plotters are graphics printers that use ink pens to create images. Plotters are especially designed for industrial applications such as producing over-sized blueprints and engineering documents. Instead of using dots to form pictures, a plotter actually draws point-to-point lines directly from graphics files by moving pens over paper. The pen plotter's precise resolution supports it use for computer-aided design (CAD) printing. 
376Lesson 37: Modems
37737.1 What is a modem?
378A modem, short for modulator-demodulator, is an electronic device that converts the digital signals produced by a computer into specific frequencies for travel over telephone or cable television lines. This conversion is referred to as modulation. FM radio stations use a similar process to convert music into radio waves. After arriving at its destination, a modem receives the frequencies and demodulates the information, converting them back into digital code.
379Modem Communication
380 
381After understanding how a modem modulates and demodulates data to enable computer communication, the next step is to understand how the computer sends and receives data. Most stand-alone modems communicate asynchronously.
382During asynchronous communication the sending device sends a start bit, alerting the receiving device to the fact that the next eight bits (one byte) are going to be a data packet followed by one stop bit to signal the end of a packet. Each eight-bit packet is the equivalent of one letter or number. Between each letter and number in every transmission, the modem sends/receives a start and stop bit. Asynchronous communication contrasts with synchronous communication, which uses a clock to synchronize data transfers, negating the need for the extra overhead of start and stop bits. Synchronous modems are used for high-end systems' communication needs.
383Regardless of whether a modem uses asynchronous or synchronous communication, modems are capable of sending and receiving data simultaneously. The ability to receive and send at a single time means modems are capable of full duplex transmissions. Full duplex mode is when the modem sends data bits out on one pair of wires while receiving data bits on another pair.
384 Editor's Note
385Although modems can send and receive simultaneously, they may not necessarily send and receive at the same speed. For example, a 56Kbps modem can receive data at 56K, but can only send data at 33.6Kbps. Devices that can send and receive data—but not simultaneously—are known as halfduplex.
386Modem Form Factors
387 
388There are two main modem form factors: internal and external. A modem connected directly to the motherboard inside a computer is called an internal modem. A modem that resides outside a computer and connects to the computer through a modem port is called an external modem.
389•	An internal modem plugs into a computer's expansion slot and draws power from a computer's power supply unit. An internal modem does not display a series of indicator lights. Instead, users rely on the internal modem's communications program for information regarding changing modem states.
390•	Residing outside a computer, external modems once connected to a computer by way of cable plugged in to a computer's serial port or USB port. This is no longer the case. Modern modems connect directly to the computer via an Ethernet cable. One advantage of external modems is that the status lights are located on its front face, giving the user easy access when troubleshooting.
391•	Lesson 37: Modems
392•	37.2 Types of Modems
393•	Today, there are a number of different types of modems, each matching up with a specific type of Internet connection (such as dial-up, cable, DSL, etc.).  Although not all of these types of connections require conversion between analog and digital form, the collection of devices used to connect a PC to the Internet are collectively referred to as "modems."
394•	Below is a summary of uses and advantages of three common modem types: 
395•	Broadband Modems
396•	A broadband modem is a type of digital modem used with high-speed DSL or cable Internet service. A cable modem is used to connect a computer to cable TV services that provide Internet access, while DSL modems connect to residential public telephone service. 
397•	While broadband modems use complex waveforms to carry digital, rather than analog data, they are still classified as modems. 
398•	Wireless Modems
399•	Modems using mobile telephone services are called wireless modems (also known as mobile or cellular modems). Wireless modems provide internet access while on the move, or when a connection to a wireless access point is not always reliable. Connect cards, slide into a PCMCIA/PC or ExpressCard slot whereas USB wireless modems use USB ports. Wireless modems may also be embedded inside a laptop or a cellular router. Most cellular routers provide multiple connections while wireless modems support one connection. Just like mobile phones, wireless modems can be sim locked for particular service providers.
400•	 
401•	 Editor's Note
402•	In other parts of the world, a USB mobile broadband modem may also be referred to as a dongle.
403•	Dial-up
404•	 
405•	A dial-up modem, still used by some home users to connect to the Internet, are capable of download speed of up to 56 kbit/s. Popular in the late 1990s, their use has sharply declined in most developed countries as broadband technologies have been implemented with DSL and cable Internet, along with mobile data services such as 4G. 
406•	The Hayes Command Set
407•	The vast majority of dial-up modems use the Hayes command set in numerous variations. A standardized set of instructions to control modems, the Hayes command set was adopted by other manufacturers to ensure their product was compatible with other computer systems. The term "Hayes compatible" is synonymous with the ability to support AT (Attention) commands. 
408•	AT commands send instructions to the modem. However, applications that require a modem are able to send AT commands automatically. Therefore, AT commands are seldom used by computer users. Technicians, however, need to be familiar with helpful, troubleshooting AT commands. If your computer is in terminal or HyperTerminal mode and you have a modem installed, you can use AT commands to access, diagnose, or manipulate your modem.
409•	 
410Lesson 37: Modems
41137.3 Connection Types
412As the demand for faster, more efficient internet connections increase, so do the number of options developed to meet these needs. Following is a brief description of some common connectivity choices available today:
413Cable
414 
415Cable Internet access provides increased bandwidth and dramatically increases the speed between the user's computer and ISP. Cable modems provide connectivity using a broadband Ethernet access method, resulting in constant online service running at approximately 30Mbps, although speeds can vary. Ethernet is a shared medium; therefore, access speed will vary depending on how many customers are sharing the bandwidth.
416Bandwidth is a measure of how much data can be transferred along a particular pathway. Like a highway, the more lanes that exist, the more traffic that can proceed, at a faster pace through those lanes. When the highway traffic bogs down with a lot of cars, everyone slows down.
417DSL
418 
419DSL technology caters to two types of uses: asymmetric DSL (ADSL) is for Internet access where quick downstream is required, but slow upstream is acceptable. Symmetric DSL (SDSL, HDSL, etc.) is designed for shorter distance connections that require high speed downstream and upstream.
420 
421Essentially DSL is a home- or office-installed digital phone line that allows a computer to bypass analog transmissions. DSL speeds depend on the distance between a customer and a telephone central office. With greatly increased digital service, this is widely available today. A DSL will provide a constant connection.
422Leased Line
423 
424Most commonly used by businesses for their faster data transfer rates and cost-effective Internet access, a leased line connects two locations for private voice and data communications. Like cable, leased lines offer a permanent, available anytime connection. Two common leased lines are T-1 and T-3.
425 
426A T-1 connection operates at 1.55 megabits per second (Mbps). 
427A T-3 is the equivalent of 30 T-1 lines, offering 45Mbps transfer rates. Both T-1 and T-3 are broadband digital network connections and are intended for business use or environments where many users will need to access the Internet simultaneously.
428Dial-Up
429 
430Dial-up is the oldest form of internet connection, capable only of 56Kbps or lower. It uses your phone line to connect to your Internet Service Provider (ISP). Also, if you only have one phone line you won’t be able to access the internet while talking on the phone. Dial-up modems are much slower compared to cable and DSL and are rarely used in most developed areas.
431ISDN
432 
433An integrated services digital network (ISDN) is an international telecommunications standard for the transmission of voice, video, and data over digital lines, and runs at 64Kbps.
434 
435Telephone companies often use a single 64Kbps channel for digitized, two-way voice transmissions. ISDN service is available in most parts of the U.S. ISDN connectors are not considered actual modems.
436Wireless
437 
438Wireless communication is a radio transmitted connection between sender and receiver that take place via airwaves. Various wireless transmissions include infrared line of sight, cellular, microwave, satellite, packet radio and spread spectrum. Multi-party teleconferencing, personal digital assistants, distributed work sessions and electronics newspapers are a few applications for wireless networks.
439Wireless is the freedom of mobility without losing a connection. Other benefits include greater range and the fact that no cables are required.
440 
441Fiber Optics
442 
443Fiber optics offers outstanding speed and bandwidth. However, it is expensive and typically used by businesses due to the costs. Fiber to the Home (FTTH) provides high-speed connectivity to homes such as Verizon’s FiOS, which provides single-mode optical fiber to the home. FiOS bundles Internet access with phone and television services. 
444 
445Cellular
446 
447While connecting to the Internet using WiFi is the easiest method for mobile computing, connecting with a cell phone is possible under other conditions. Most cell phone companies allow users to access the Internet through their laptops/notebooks.
448•	Digital mode phone: a dual mode phone operates on both the 1900 MHz and 800 MHz digital networks while a tri-mode phone can additionally operate on the 800 MHz analog network. 
449•	Data port – most modern cell phones have a port that allows you to connect to various Internet connecting devices 
450•	Special cable or connecting devices—including any software that may be required to connect to your laptop 
451•	Proper service plan—one that includes data services 
452•	Internet Service Provider (ISP)
453 
454Developed in the early 1980s, the older Advanced Mobile Phone System (AMPS) uses analog technology, so it does not offer Web browsing or e-mail services. Neither does Narrowband Advanced Mobile Phone System (NAMPS) since it operates only on the 800 MHz band.
455Second generation (2G) cell phones launched in 1991. These digital devices use one of three technologies:
456•	Frequency division multiple access (FDMA) – too inefficient to be adopted 
457•	Time division multiple access (TDMA) – uses channels and operates digitally in either the 1900 or 800 MHz frequencies 
458•	Code division multiple access (CDMA) – a form of spread spectrum technology 
459TDMA is the access method that was adopted by the Telecommunications Industry Association (TIA) and Electronics Industry Alliance (EIA). Fastest download speeds for second generation cell phones is up to 144Kbp.
460The new Millennium brought great improvements. Third generation (3G) cell phones are significantly faster and more efficient; thus, they are much better for downloading from the Internet. With transfer speeds approaching 3 Mbps third generation phones can perform various broadband applications—streaming audio/video from the Web, handing e-mails with attachments, video conferencing, etc.
461Common technologies used by third generation cell phones are:
462•	CDMA2000 
463•	Wideband Code Division Multiple Access (WCDMA) 
464•	Time-division Synchronous Code-division Multiple Access (TD-SCDMA)
465The recent release of 4th generation (4G) cell phones provides transfer speeds of up to 100 Mbit/s.
466 
467WiMAX
468 
469WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communications standard that delivers high-speed broadband internet access over a wireless connection. Unlike other wireless technology, WiMAX doesn’t require a direct line of sight between the source and its endpoint. Providing a shared data rate of up to 70Mbps, WiMAX is considered to be the ultimate solution to deliver broadband to locations where wired connections would prove to be too difficult or costly.
470Satellite
471 
472Internet over Satellite (also referred to as IoS) uses a satellite to handle data transmissions. Unlike cable or DSL where speed fluctuations can and will occur, satellite internet allows for smoother connections. 
473 
474Combined with an outdoor antenna and subscription to a satellite service, a satellite modem is one of the fastest modem options available and remains a top choice for users in remote locations where conventional forms of connectivity are not available.
475Lesson 37: Modems
47637.4 Modem Components
477Since the majority of users today access their Internet via a cable modem, it is important to have a basic understanding of common components featured on a standard cable modem.
478Internal Components
479 
480Internal components of a typical cable modem contain a tuner, demodulator, modulator, MAC device, and microprocessor.
481•	The tuners job is to separate the Internet channel from normal television channels and pass the signal to the demodulator.
482•	The Demodulator and Modulator control the duplex of information in the cable modem. The demodulator takes the signal from the tuner and converts it from analog to digital, checks the signal for any errors, then arranges and corrects them.  Upstream data is handled in the modulator where information is moved in reverse order. The data is first checked for errors and then converted from digital to analog for outbound transmission.
483•	Every networking component receives its own unique MAC address and the cable modem is no different.  The MAC device in a cable modem acts to manage the hardware and software of network protocols.  
484•	If more complex tasks are necessary such as receiving user input, they are sometimes carried out by a microprocessor.
485External Modem Lights
486 
487External modems are equipped with indicator lights that show what is happening during the communication process. Knowing what each light means helps to troubleshoot modem problems and is important to understanding a modem's status.
488 
489•	STANDBY BUTTON – Offers added Internet Security.  When pressed, interrupts Internet connection until pressed again.
490•	POWER LED – Flashes when startup is being performed.  A solid light indicates modem is turned on.
491•	RECEIVE LED – Flashes when scanning for a receive channel connection.  A solid light indicates the connection is acquired.
492•	SEND LED – Flashes when scanning for a sends channel connection.  A solid light indicates the connection is acquired.
493•	ONLINE LED – Flashes when scanning for a network connection.  A solid light indicates the network connection is acquired.
494•	PC/ACTIVITY – Flashes when transmitting or receiving data.  No light indicates the modem is not transmitting or receiving data.
495•	STANDBY LED – A solid light indicates the Internet service is blocked because the standby button on top of the modem was pressed.  If this light is on, all other lights are automatically turned off.
496•	Lesson 26: Hard Drive Interfaces
497•	26.1 Hard Drive Interfaces
498•	A hard drive, together with hardware and software necessary for the hard drive to exchange data with the computer's motherboard, is the hard drive "interface." The ST-506, ESDI, IDE, ATA, and SATA (Serial ATA) drives are frequently called hard drive "interfaces."
499•	 
500•	Earlier hard drive interfaces required a separate controller which would attach to the motherboard through an expansion slot, such as ISA. In modern drives, the controller has been moved from a separate board and integrated directly into the hard drive. This innovation allows hard drive manufacturers to fine-tune the controller specifically to the device being controlled, instead of relying on a generic controller.
501 
502•	
503Lesson 26: Hard Drive Interfaces
50426.2 Early Interfaces
505As hard drive technology has evolved, so have the hard drive subsystems that make up the drives. 
506ST-506 (The First Hard Drive)
507 
508The first hard drive type was the ST-506. The ST-506 controller was on a separate expansion board that was plugged into the motherboard through an expansion slot. The hard drives were considered "dumb" because they did not have a controller integrated onto them. Since the controller worked with many different brands and sizes of hard drives, it had to be a very generic interface. Drive manufacturers were not able to customize their hard drives to optimize size and speed because of ST-506's generic nature.
509Configuring ST-506 drives was cumbersome because the controller was not integrated with the drive. One complication was defect mapping. 
510All drives contain bad or defective sectors that cannot be used. Defect mapping—finding and configuring bad sector information—was done manually with ST-506 drives. This meant the user had to get a list of the bad sectors from the manufacturer and manually input the addresses of bad sectors as part of the configuration process.
511Enhanced Small Device Interface (ESDI)
512 
513The Enhanced Small Device Interface (ESDI) offered some improvements over the ST-506, but never gained popularity due to superior interfaces that soon followed.
514ESDI offered two primary advantages. First, ESDI was faster than the ST-506, offering up to 2.4 megabyte per second faster transfer rates. Second, ESDI offered automatic defect mapping, making configuration an easier task. Besides these two advantages, system software written for ST-506 drives was compatible with ESDI drives, which was helpful for upgrading.
515Both ESDI and ST-506 drives used one-bit-at-a-time serial data transfer that would be improved in future hard drives.
516Integrated Drive Electronics (IDE) and ATA-1
517 
518To make hard drives faster and easier to install, the Integrated Drive Electronics (IDE) was developed. Previously, ST-506 and ESDI hard drives were cumbersome to configure because the separate controller card had to be configured. ST-506 even required two cables be connected to the hard drive for data communications. IDE did exactly what its name implied, "integrated" the controller and drive into one unit, requiring one configuration and only one data cable. Today, the IDE interface is more commonly referred to as ATA or Parallel ATA (PATA).
519Considered the original standard defining compatible register sets, the ATA has 40-pin connector ribbon cables and accompanying data signals. Unlike its predecessors which used serial data transfer, the ATA family of drives can transfer data in parallel, allowing sixteen bits to be transferred at one time.
520ATA-1 specifies two methods to transfer data from the hard drive to the system: Programmed Input/Output mode (PI/O) and Direct Memory Access (DMA).
521•	PIO (Programmed Input/Output) mode allows peripherals to exchange data with the RAM with the help of commands managed directly by the processor. PI/O's major advantage is its compatibility. All IDE hard drives must be able to use PI/O 0 if needed. PI/O has a major drawback, however. It requires the CPU to control all of the data transfers to and from the drive, wasting precious CPU time. In fact, PI/O data transfers can consume over 90% of the CPU's time, leaving very little left over for other work. 
522•	DMA modes allow the CPU to issue requests for data to the DMA controller on the motherboard. The DMA controller can then manage the data transfer between the hard drive and the system, allowing the CPU to spend its time performing other tasks. Unfortunately, DMA needs to be supported by the operating system, and some manufacturers did not implement DMA properly on their drives when DMA was released thus, many users were not able to take advantage of DMA technology during the early days of IDE drives.
523Since the adoption of ATA-1 standards, the industry has proceeded to ATA-7, defining standards to improve limitations and technology. For many years ATA provided the most common and the least expensive interface for this application. It has largely been replaced by Serial ATA (SATA) in newer systems.
524Enhanced IDE (EIDE) and ATA-2
525The ATA standard needed to be revised to support newer hard drives that boasted better speeds and greater capacities. The first such revision occurred in 1996 and was called ATA-2 (also referred to as EIDE (Enhanced IDE). ATA-2 made a number of changes over ATA, including support for added PIO and multiword DMA modes, allowing a significant increase in maximum disk size thanks to LBA (Logical Block Addressing).
526ATA-2 defined LBA to be a new method of tracking sectors on a hard drive. Instead of the old CHS method, each sector on the drive is assigned a linear number in a progressive order. By the LBA method, the BIOS recognizes the first sector of the hard drive as "0", the next sector is labeled "1", and so on. 
527 
528ATA-3
529The ATA-3 interface features S.M.A.R.T. technology, which allows ATA-3 to communicate interface problems.
530S.M.A.R.T. gives IDE drives the ability to log errors that might result in the drive's malfunctioning. ATA-3 also introduced password security for device access.
531ATA-4
532ATA-4 combined a number of unofficial standards, (including ATAPI and UDMA) into one official standard. ATAPI also added features to allow ATA to perform better under multitasking environments. ATA-4 also specified new BIOS support for drives up to 9.4 trillion gigabytes (9.4 trillion billion bytes)! Even with this new BIOS support, maximum ATA drive size is approximately 138GB due to specifications created in ATA-1.
533•	UDMA - Ultra DMA uses bus mastering DMA. Bus mastering DMA improves upon standard DMA methods defined in ATA-1 and ATA-2 by allowing the hard drive controller and PCI bus to perform dynamic memory access directly. This frees the motherboard's DMA controller from handling hard drive transfers.
534•	ATAPI - ATAPI is a very user-friendly convention for interfacing peripheral drives like CD-ROM's and Zip drives on the motherboard's IDE interface. ATAPI was actually introduced around the same time as ATA-2, but it was a separate standard. Due to ATAPI's popularity and flexibility, ATA-4 added ATAPI to the official standard.
535ATA-5
536ATA-5's best known enhancement to the IDE family is Ultra DMA/66 cable. ATA-5 also introduced cyclical redundancy check (CRC). ATA-5 is compatible with legacy ATA-implementations. However, transfer rates will reflect only the maximum speeds of the legacy device.
537 Editor's Note
538Cyclical redundancy check (CRC) provides the IDE with an error checking method that can verify the integrity of transferred data. CRC works as follows: the devices involved in the transfer use a mathematical algorithm to arrive at a value, and when the data arrives at its destination, the two values will have to match.
539ATA-6
540Since 2001, ATA-6 defines Ultra DMA/100, which allows drives to, in theory, reach transfer rates of 100 Mb/s.
541ATA-7
542The ATA-7 standard defines Ultra DMA/133, which allows drives to, in theory, reach transfer rates of 133 Mb/s. 
543Transfer Mode Summary
544 
545Name	Mode (PIO/DMA/UDMA)	Transfer Rate (Mb/s)
546		
547
548Name	Mode (PIO/DMA/UDMA)	Transfer Rate (Mb/s)
549ATA-1	PIO mode 0
550PIO mode 1	3.3 
5515.2
552	PIO mode 2	8.3
553	DMA mode 0	8.3
554ATA-2	PIO mode 3
555PIO mode 4	11.1 
55616.7
557	DMA mode 1	13.3
558	DMA mode 2	16.7
559ATA-3	PIO mode 3
560PIO mode 4	11.1 
56116.7
562	DMA mode 1	13.3
563	DMA mode 2	16.7
564ATA-4/ATAPI-4	UDMA mode 0
565UDMA mode 1	16.7 
56625.0
567	UDMA mode 2	33.3
568ATA-5/ATAPI-5	UDMA mode 3	44.4 
569	UDMA mode 4	66.7
570ATA-6/ATAPI-6	UDMA mode 5	100
571ATA-7/ATAPI-7	UDMA mode 6	133
572
573Lesson 26: Hard Drive Interfaces
57426.3 Serial ATA (SATA)
575Serial ATA (SATA or S-ATA) has replaced the Parallel ATA (aka IDE) interfaces. The first SATA standard, SATA 1, supports data transfers of up to 150MB/s. SATA has been improved to currently support a maximum data transfer rate of 600MB/s. Some hard drives cannot transfer data at these speeds, however, so the actual data transfer rate depends upon the hard drive. Thus, hard drives speeds will need to improve before the benefits of this standard are more widespread.
576Only four wires are needed to support the SATA interface, compared to the 40 found in a parallel ATA cable. This makes the SATA cable much thinner and more flexible. The cables are easier to manage and do not block the airflow through the case.
577SATA is easy to configure as the master/slave setup has been eliminated. Only one hard drive can be connected to a SATA cable, but multiple SATA connectors can be placed onto a controller. 
578 
579Standardized in 2004, External SATA (eSATA) is an offshoot of SATA that offers an external storage alternative to the more common USB and FireWire interfaces. It has a transfer rate of 300MB/s with a maximum cable length of 2 meters.
580 Editor's Note
581Another method of connecting a hard drive is to use a USB port. External USB hard drives are useful for backing up data and for expanding a computer's data storage capabilities.
582 
583
584Lesson 27: Small Computer System Interface (SCSI)
58527.1 What is a SCSI?
586A Small Computer Systems Interface (or SCSI bus) is a widely used hardware interface that permits the simultaneous connection of up to 16 peripheral devices (including the adapter), using a single expansion board.
587A SCSI interface offers greater expandability. SCSI-connected peripheral devices are connected in a series called a daisy-chain. Additionally, SCSI interfaces are available with two controllers that can support a combined 30 peripheral devices. SCSI, like newer versions of IDE and SATA, also uses direct memory access (DMA), reducing the demands made on a computer's CPU.
588SCSI drives are used in computers, ranging from PCs to mainframes. (PCs usually feature IDE or SATA drives because of their lower cost and simpler configuration). A single SCSI interface can simultaneously accommodate scanners, hard drives, CD and DVD drives, and many other devices—all on the same cable. Although SCSI remains popular on high-performance workstations and servers, desktop computers and laptops have replaced SCSI interfaces with USB, eSATA, and FireWire connections for external devices. 
589The Advantages of SCSI vs. IDE 
590 
591Both SCSI and IDE or SATA offer distinct advantages. For the average home PC users, IDE or SATA has proven itself to be easy to install, operate, and upgrade. IDE or SATA is also much cheaper to implement than their SCSI counterpart. IDE and SATA do have disadvantages, on the other hand. They can only install a limited number of devices, and they have limited fault-tolerance.
592 
593SCSI has found a booming niche where multiple high speed drives are necessary to maintain servers and complex databases. SCSI can access multiple devices on the same cable at the same time, making it better for multitasking.
594SCSI buses can also include a variety of peripherals such as scanners, CD drives, and printers. SCSI also supports multiple fault-tolerant drives (RAID), ensuring data recovery in the event of hardware or software failure. SCSI's biggest disadvantages are the increased expense and more complex configurations—confusing cabling, setting proper termination, and setting device IDs.
595SCSI Bus Standards
596 
597With each advance in SCSI technology a new SCSI standard was born. The following section discusses each SCSI standard. Make sure to become familiar with each standard’s implementations and specifications
598 
599SCSI-1 Standard
600 
601SCSI-1 was the first SCSI standard. Although the SCSI-1 standard functioned the way it was supposed to, it is not nearly as efficient as today's SCSI standards. SCSI-1 adhered to the following specifications:
602 
603SCSI-1 Specifications
604Bus width	8-bit
605Transfer Speed	5MB/s
606Parity	No
607Clock speed	5MHz
608Maximum cable length	6 meters
609Maximum number of devices	8
610SCSI-2 Standard
611 
612For most new technologies to survive, they must adapt to the specific needs of IT departments. In this case, the development of the SCSI-2 standard sent a positive message to the industry that SCSI technology would provide IT departments with a tool that could be implemented in a useful and cost-effective way. 
613 
614SCSI-2 improved upon the preceding model with three separate standards: Wide SCSI-2, Fast SCSI-2 and Fast/Wide SCSI-2. SCSI-2 also supported SCSI bus parity. Which means that, like RAM, a parity bit must be sent with each data transfer, ensuring the data's integrity. SCSI-2 adheres to the following specifications: 
615SCSI-2 Specifications	
616Bus width	8-bit
617Transfer Speed	5-10MB/s
618Parity	Yes
619Clock speed	5MHz
620Maximum cable length	6 meters
621Maximum number of devices	8 or 16
622SCSI-2 Fast
623 
624SCSI-2 Fast was a slight variation of the original SCSI-2 standard. As the name implies, this standard outlined faster data transfer rates by doubling the original clock speed to 10MHz. SCSI-2 Fast adheres to the following specifications: 
625 
626SCSI-2 Fast Specifications
627Bus width	8-bit
628Transfer Speed	10MB/s
629Parity	Yes
630Clock speed	10MHz
631Maximum cable length	3 meters
632Maximum number of devices	8
633Wide SCSI-2
634 
635Wide SCSI-2 doubled the bus to 16-bits but kept the clock speed at 5MHz. This wider bus could handle transfer rates of 10MB/s. Wide SCSI is able to support 16 devices (15 devices and the adapter card). After Wide SCSI-2 was released, 8-bit versions of SCSI often became known as "narrow" SCSI. Wide SCSI-2 adheres to the following specifications: 
636 
637Fast/Wide SCSI-2 
638Fast/Wide SCSI-2, the third generation of SCSI-2 technology, introduced a 10MHz clock and a 16-bit bus, quadrupling the SCSI-1 transfer rate to 20MB/s. Fast/Wide SCSI-2 supports the same number of devices as Wide SCSI-2. Fast/Wide SCSI-2 adheres to the following specifications: 
639 
640 Editor's Note
641SCSI-2 also introduced command queuing. Traditionally, read and write requests could only be sent one at a time. Command queuing allows multiple requests to be sent to a device at once. Some IDE devices now support a limited form of command queuing, but the SCSI implementation offers higher performance.
642Ultra SCSI/Ultra-Wide SCSI
643 
644Ultra SCSI (also known as Fast-20) uses a 20MHz clock and an 8-bit bus allowing maximum data transfer speeds of 20MB/s. The Ultra-Wide version increases the bus width to 16-bits, allowing 40MB/s. Ultra SCSI and Ultra-Wide SCSI adhere to the following specifications: 
645 
646 
647Ultra-2 SCSI/Ultra-2 Wide SCSI
648 
649Ultra-2 SCSI uses a 40MHz clock and an 8-bit bus allowing maximum data transfer speeds of 40MB/s. The Ultra-2 Wide version increases the bus width to 16-bit, allowing 80MB/s. Ultra-2 SCSI also uses low-voltage differential signaling to accommodate longer cable lengths. Ultra-2 SCSI and Ultra-2 Wide SCSI adhere to the following specifications: 
650 
651 
652 
653SCSI-3 (Ultra-3, Ultra 160 or Ultra SCSI)
654 
655The SCSI-3 standard uses a 16-bit bus enabling maximum data transfer speeds of 160MB/s. Unlike the previous versions of SCSI (such as Ultra-2), there are no "narrow" 8-bit versions of Ultra-3, Ultra 160 or Ultra 320 SCSI. 
656 
657Ultra 160 SCSI transfers data as fast as Ultra-3 SCSI (160MB/s), but it improved upon previous SCSI standards and includes features that ensure reliable data transfer. Ultra 160 SCSI uses a process during boot-up called Domain Validation to ensure that all of the devices on the SCSI chain can be used reliably at maximum speed. If a device cannot be used at the highest level of performance, Ultra 160 SCSI will slow down until it finds a reliable speed. 
658Both Ultra SCSI and Ultra160 SCSI use the low-voltage differential signaling to accommodate longer cable lengths. These versions of SCSI are sometimes referred to collectively as Low-Voltage Differential (LVD) SCSI. Ultra-3 SCSI adheres to the following specifications: 
659 
660 Editor's Note
661If only one device, besides the SCSI adapter, is on the SCSI chain, then LVD is capable of cable lengths up to 25 meters.
662The most important advice to heed when dealing with modern SCSI equipment is to check (and double check) with the manufacturer to ensure that your SCSI device, SCSI adapters and cabling are compatible with your needs. 
663Lesson 27: Small Computer System Interface (SCSI)
66427.2 SCSI Signaling Types
665A technician's SCSI knowledge includes being familiar with types of available SCSI signaling methods. 
666Currently there are three different ways SCSI devices can transmit on a cable:
667•	Single-ended
668•	Low voltage differential (LVD)
669•	High voltage differential (HVD)
670Each is designed to work with a specific SCSI bus, but some may be compatible with more than one type of SCSI bus.
671 
672Single-Ended SCSI
673 
674Single-ended (SE) devices were common until the recent introduction of Low Voltage Differential signaling. Single-ended SCSI uses two wires for each pin; one carries the signal and the other is a ground. This configuration is not as good at dealing with EMI and RFI as the differential signaling methods, which are explained below.
675Single-Ended SCSI signaling is still common with slower devices, such as CD-ROMs and scanners. Singleended SCSI is limited to 1.5 meters to 6 meters in length, depending on the implementation.
676High Voltage Differential (HVD) SCSI
677 
678HVD, like single-ended signaling, uses two wires per pin. Instead of one wire carrying a signal and the other serving as a ground, both wires carry the signal. One wire carries a positive voltage version of the signal, while the other wire carries a negative version of the signal. This differential signal helps combat EMI and RFI. Because HVD carries a higher voltage through the SCSI bus it is possible for the cable to extend 25 meters, more than twice the distance of LVD and four times the length of SE.
679HVD was ahead of its time when it was released. HVD signaling was not yet reaching its limitations, but it did not catch on due to the extra cost to implement HVD. It is now considered obsolete.
680Low Voltage Differential (LVD) SCSI
681 
682Like HVD, LVD uses a positive and negative version of the signal for each ping. The difference between LVD and HVD, as their names imply, is the amount of voltage used. LVD can carry a signal up to 12 meters. LVD is quickly becoming the most common form of signaling.
683Compatibility
684 
685Some LVD devices are capable of running on the same cable with SE devices. These devices are referred to as multimode devices. If a multimode device is placed on an SE chain, it loses all of the benefits of LVD and behaves as a SE device.
686Mixing any HVD devices into either a single-ended or LVD bus is not possible and will probably damage the SCSI components and SCSI adapter. All of the forms of signaling use the same connectors, so it is easy to mistakenly connect a HVD device to a SE chain.
687Refer to manufacturer documentation to determine whether specific LVD devices support multi-mode operations or simply support the ability to work as both an LVD device and a single-ended device. Recognizing appropriate device support is important because when you combine HVD and LVD on the same bus, the LVD device will need to work as a single-ended device. 
688 Editor's Note
689Connecting an HVD device to a LVD or SE can destroy all of the devices on the chain! Due to the fact that all forms of signaling use the same connectors, it is important to know the signaling type of your SCSI devices. Refer to the device manuals for more information.
690
691Lesson 27: Small Computer System Interface (SCSI)
69227.3 Configuring SCSI Drives
693Physically, a SCSI drive is similar to an IDE drive. Both drives bolt to a PC chassis (if the drives are internal) and accommodate cables connecting a computer and fixed disk drive. 
694 
695SCSI drives tend to be more difficult to install than IDE drives. Simply cabling a SCSI drive requires establishing SCSI bus termination and device addressing. Now that you are familiar with the different types of SCSI characteristics, it is important to understand how to correctly configure SCSI devices.
696There are three areas to consider: termination, SCSI identification numbers (SCSI IDs), and cabling. 
697Termination
698If a SCSI chain is not terminated, the signal will bounce back at the end of the cable, creating echoes on the cable. These echoes will interfere with the operation of all of the devices on the SCSI chain. Terminators are placed at the ends of the SCSI chain to absorb the signal, preventing echoes.
699 
700Each end of a SCSI cable must be terminated in order for all the devices along the cable to work without glitches. If your devices are all internal, or all external, then you can easily terminate the SCSI cable at the last device and at the adapter. Some advanced adapters and devices feature automatic termination.
701 
702 Editor's Note
703Mixed SCSI systems (devices located internally and externally) also need to be terminated at the first and last device. But with mixed systems, the adapter is not the first device: with mixed systems, the adapter is in the middle. Therefore, with mixed systems, the adapter should not be terminated as if it were on an internal-only or external-only system.
704Often SCSI devices come with a terminator already on. This terminator needs to be removed when configuring your devices
705 Editor's Note
706The last device in a SCSI daisy chain must be terminated so the computer knows there are no more devices to consider for priority. Terminate a device by either setting a switch or plugging a resistor module into a device's outgoing port.
707Types of Terminators
708 
709Understanding where to terminate the SCSI bus is half the termination battle. The other half requires understanding what type of terminator to use. Currently there are four types terminator types: passive termination, active termination, forced perfect termination (FPT), and low voltage differential termination.
710•	Passive
711Passive termination can be considered the simplest form of termination, consisting of a series of resistors. The passive scheme is most effective with slower transfer rates over short distances. As SCSI standards improved, the types of terminators also adapted to keep pace.
712•	Active 
713Passive terminators use resistors to bring down the circuit's voltage. But passive termination is not as accurate as active termination which actually induces a specific termination voltage with the use of voltage regulators. Active termination is required for Fast and Wide SCSI configurations. 
714•	Forced Perfect Termination (FPT) 
715Forced Perfect Termination is a type of active termination that employs a diode to exact a specific voltage to terminate a SCSI device more effectively than active or passive. FPT is an improvement over basic active termination because forced perfect termination protects against signal overshoot and undershoot. Different types of FPT terminators are available, each catering to specific SCSI termination needs.
716•	Low Voltage Differential 
717Low Voltage Differential terminators are designed to work on LVD buses. However, in many cases, LVD devices may co-exist on a single-ended bus. If you use single-ended terminators, then LVD devices will function as single-ended.
718SCSI ID
719 
720Devices connected to a SCSI drive interface are often daisy chained together. Most external SCSI devices have two ports: one for incoming data and one for outgoing data traveling to the next device. 
721Internal devices usually have just one port that connects to a ribbon cable. Whether one port or two port, each drive is assigned a unique identification number based on the total number of devices. 
722For example, if you have eight devices, each device will get a number between 0 and 7. Device IDs are actually binary numbers, and internal device IDs require setting a binary sequence with jumpers on the back of the device. A closed bridge with a jumper represents a "1" and an open bridge without a jumper represents "0."
723 
724 Editor's Note
725A device ID is established by flipping electronic switches on external devices and by setting jumpers in binary sequence for internal devices. A SCSI ID determines a device's "priority" number. From highest to lowest, the priority order is 7 to 0 and then 15 to 8.
726Although a SCSI bus can accommodate up to 8 devices (16 in the Wide versions), one of those devices always has to be the adapter.  The adapter, like any other device on  the SCSI bus, needs an identification number, which is usually preset (and not changeable) at 7 from the factory.
727Which of the following is true about SCSI ID priority? A. 8 is the highest.
728B.	8 is the lowest.
729C.	15 is the highest.
730D.	15 has a higher priority than 0.
731E.	7 has a lower priority than 15.
732Cabling
733 
734As you've already learned, there are many different SCSI "flavors." Therefore a host of different cables and connectors connect SCSI devices. Connecting devices to a SCSI bus requires a pin connector and an accompanying conductor cable. A technician needs to know which cable-connector goes with which type of SCSI bus.
735One important aspect of SCSI cabling is that newer, high-speed SCSI drives are extremely sensitive to and dependent on proper installation and cable condition. It is important to use the utmost care with a SCSI's cables because a bent pin or loose cable can cause severe malfunctions.
736•	Centronics connector
737The first type of SCSI device interface was the low-density 50-pin Centronics connector. The 
738Centronics connector is attached the device on one end, with the Centronics 50-conductor cable (known as an A cable) leading from the device to the SCSI card. Internal SCSI devices connected to the SCSI bus, using an unshielded 50-pin flat cable. External SCSI devices take advantage of the shielded 50-pin Centronics connector. 
739 
740SCSI-2 updated the original 50-pin Centronics (which is very large) connector to be more practical. The high density 50-pin D shell connector was the solution. This new connector looks like a slimmed down version of the original low density 50-pin Centronics connector. One good thing about the high density 50-pin D shell connector was that it still attached to the same A cable.
741•	68-Pin Connector, the B Cable
742To accommodate 8-bit and 16-bit bus widths outlined in SCSI-2, the industry developed a 68-pin connector and conductor cable (B cable). B cable was not independent, and still needed to be used with A cable. Consequently, the B cable was quickly phased out with the inception of SCSI-3 standards.
743 
744•	68-Pin D-Shell Connector, the P cable
745The 68 conductor cable was modified to complement a new 68-pin shielded ( for external devices) and unshielded (for internal devices) D-shell connector. This connector looks a lot like the 50- pin D shell, but is a little longer. 
746A new P cable was outlined for SCSI-3. Although P cable was not mandated for SCSI-2, a lot of SCSI-2 devices incorporated the P cable because it was more practical than A and B cable combination.
747	•	Alternative-4
748The latest innovation in SCSI cabling is Alternative-4. Alternative-4 refers to an 80-pin connector used for Wide SCSI implementations. Alternative-4 enables hot-swapping, or the removal and addition of devices while the power is on. 
749Remember, it is important to adhere to specifications governing SCSI cable length. Unless you are using a differential SCSI bus (differential SCSI will be discussed later in this lesson), your maximum cable length will be limited to 6 meters.
750Low-Level Formatting 
751 
752Low-level formatting of a SCSI disk can help to remedy corrupt drives. With low-level formatting, the tracks and sectors are created on the hard drive's blank magnetic patterns. Low-level formatting of SCSI drives by the end-user can only be performed on very old SCSI drives, but it may help save a preciously needed drive. Modern SCSI hard drives are low-level formatted at the factory and cannot be low-level formatted by the end user. Older SCSI hard drives, like the obsolete MFM, required the user to perform low-level formatting. 
753 Editor's Note
754Low-level formatting is very useful when trying to eradicate a particularly troublesome virus. Also, it usually detects physical errors on hard drives and maps them so they will not be used for storage. 
755Low-level formatting can sometimes be performed to repair a corrupted hard drive. As a drive gets old, its heads may start to drift due to wear and tear. Even a millimeter of drift could disable a hard drive since it will no longer be able to find the data. Low-level formatting creates new tracks and sectors that are adjusted for the drift. (Check with the hard drive's manufacturer to be certain low-level formatting is possible on the specific hard drive.) A hard drive that is old enough to experience head drift should be replaced.
756Low-level formatting is performed by the SCSI controller. The user issues commands with the SCSI BIOS ROM found on SCSI controllers or diagnostic software accompanying a SCSI drive. SCSI BIOS ROM also allows SCSI drives to act as boot drives. However, if your SCSI card does not have its own BIOS, the system cannot boot from a SCSI device.
757 Editor's Note
758WARNING: Low-level formatting erases all data stored on hard drives. Further, low-level formatting, when performed improperly, can destroy the hard drive. Always consult with the hard drive's manufacturer or documentation before performing low-level formatting.
759Other SCSI drives, such as CD-ROM drives, have installation requirements similar to those SCSI hard drives, connecting to the SCSI bus like any other internal or external device. The major difference between a SCSI hard drive installation and other SCSI devices is that the SCSI device often requires a special driver for proper operation. You need a software driver specific for your operating system. Drivers are usually provided on disks with the SCSI device or at the manufacturer's Web site.
760 Editor's Note
761WARNING: There are SCSI utilities and BIOS routines that claim to provide low-level format functions. This is not the same as the manufacturer's low-level format. These functions force the SCSI drive to overwrite data on a hard drive with 0s or 1's, or some pattern, erasing all data on the drive.
762Troubleshooting
763 
764SCSI is a wonderful bus for supporting multiple devices, but it can be quite complex.  Fortunately, there are several generic strategies that work to solve many common SCSI related problems.  Below is a list of some typical SCSI errors and some associated troubleshooting tips.
765	•	Missing Devices
766It is not uncommon for a SCSI adapter to not realize that a new SCSI device has been added to a SCSI chain. When this happens there are a few places to check. First, make sure the device is turned on. Turn on external SCSI devices before powering on the PC, otherwise they will not be seen by the SCSI adapter during boot-up. 
767Make sure the device is properly terminated. For example, if a new hard drive is added but not acknowledged, it is an indication that the hard drive immediately before it on the SCSI cable may be terminated, preventing the SCSI chain from reaching the new hard drive. 
768Also, make sure the proper type of device is being attached to the cable. For example, if the SCSI adapter only supports LVD and you connect a SE device, the chain will not work properly.
769If this does not solve the problem, check the new device's ID. Make sure it is unique and not conflicting with other devices on the chain—don't forget that the SCSI adapter also uses a device ID.
770•	Drivers
771SCSI cards need drivers. Make sure the proper drivers are installed for the operating system in use.
772•	SCSI Device Malfunctions
773Check termination. If termination is not activated, or improperly installed, all sorts of odd problems may occur—most notably, data corruption. Make sure the proper terminator is used because different types of SCSI need different types of termination. Refer to the SCSI adapter's manual to see what type of terminator is recommended for a specific configuration. 
774Also, check cabling types and lengths. Using the improper type of cable, or exceeding cabling length, will also result in intermittent problems.
775Lesson 27: Small Computer System Interface (SCSI)
77627.4 Fault Tolerance and RAID
777A distinct advantage of using a SCSI interface on a network server is that several hard drives can be easily configured as a fault-tolerant Redundant Array of Inexpensive Disks (RAID). A RAID can described as a data storage system combining multiple disk drives into a single logical unit with data redundancy and improved efficiency.
778 
779With fault tolerance, a failed drive can be removed, and a new one can be inserted without any loss of data—all while the system is still operational. SCSI-based RAID systems are widely used in file servers, database servers, and other network servers.
780Since almost all modern hard drives are considered inexpensive compared to ten years ago, RAID is sometimes called a Redundant Array of Independent Disks. 
781How data is written to the drives influences the RAID'S speed and performance and also how fault tolerance is implemented in the event of a failure. Depending on the storage system used, it will likely be one of many different RAID configurations, or "RAID levels". 
782Factors to consider among different RAID levels are: 
783•	Reliability
784•	Availability
785•	Performance
786•	Capacity RAID 1
787 
788RAID level 1 uses mirroring, a type of fault-tolerance that safeguards against lost data. 
789Mirroring does just what its name implies: creating a mirrored image of all data on a partner disk drive. When a primary drive fails, the controller switches instantly to the second drive containing the mirrored data. Although RAID 1 provides fault-tolerance, writing data occurs more slowly in a RAID 1 configuration due to the creation of multiple copies.
790 
791RAID 1 requires two hard drives. One drive is active and one is the mirror. Since all data is duplicated, only half of the total hard drive space is usable.
792RAID 0
793 
794RAID level 0 uses striping, allowing for the fastest read/write performance. Data is broken into blocks and then simultaneously written to multiple hard drives. With multiple hard drives working together as one, data can be read and written much more quickly than if just one drive was used.
795RAID 0 requires at least two hard drives to be implemented. Due to the fact that there is no parity information or mirroring function in RAID 0, all stored data is lost permanently if one drive in the RAID fails. 
796 
797RAID technology is constantly advancing, with new innovations adapting to new technology. If you are interested in learning more specifics about RAID check the following Web sites: www.adaptec.com (http://www.adaptec.com) or www.digidata.com (http://www.digidata.com).
798RAID 3
799 
800RAID 3 combines two separate features to provide faster reading and simultaneous fault tolerance. Like RAID 0, RAID 3 provides striping to speed up data transfer, but it also includes an extra disk to store parity information. In the event of a crashed drive, lost data can be rebuilt using the data on the parity disk.
801 
802Compared to RAID 0, write times are slower with RAID 3 because data is written to the striped sets and then parity information is written to the parity drive. RAID 3’s performance also lags because it uses bytelevel striping, rather than blocks like RAID 0.
803Implementing RAID 3 requires at least three drives—two for striping and one for parity. More disks can be added, keeping in mind that the parity drive must always be at least equal to the size of the other striped drives.
804RAID 5
805 
806RAID 5 is the most common RAID currently in wide use because RAID 5 supports striping and parity for fault tolerance. 
807Parity data is generated from the data it receives from the computer. The data and parity information is then evenly divided among the multiple hard drives in the RAID. 
808If one hard drive fails, lost data is recovered by combining the remaining data on the good hard drives with the parity information stored on the good hard drives. The computer will still function, but it will run much slower because the data needs to be reconstructed on the fly. When the bad hard drive is replaced with a new drive, the computer will return back to full performance levels.
809 
810RAID 5 requires three hard drives to be implemented. One of RAID 5's disadvantages is inefficient use of hard drive space. The parity information takes up enough space to equal one hard drive. If you have four 5GB drives in a RAID 5 configuration, you can only use 15GB of storage, as 5GB are consumed by parity.
811RAID 10
812 
813A RAID 10 configuration has the best of RAID 1 and RAID 0; that is why it is sometimes referred to as RAID 
8141+0. As with RAID 1, RAID has redundancy requiring twice the number of disks for mirroring. As with a RAID 0, RAID 10 spreads data evenly across all the drives. RAID 10 offers high fault tolerance, high data availability, and has the fastest disk access. Since it is very costly to implement and drive spindles must be synchronized, it is ideal for databases that frequently have write operations and where high performance and redundancy are critical.
815Depending on the specific drives lost, it is possible for a RAID 10 array to lose up to half of its hard drives and continue functioning. RAID 10 boasts better performance than RAID 5 but suffers from RAID 1’s inefficient use of space.
816 
817RAID 30 (also known as RAID 3+0) is a combination of RAID 3 and RAID 0. It offers high data transfer rates and high data reliability. It achieves this by striping across a number of RAID 3 sub-arrays. The simplest RAID 30 configuration, for example, features a minimum of six drives. Four drives are used to store striped data, while two are used for parity information. The drives are distributed evenly with two data drives and a single parity drive on each side of the RAID 30 array. RAID 30 is very costly to implement and best for data warehousing.
818RAID 50
819 
820Similar to RAID 30, RAID 50 is very costly to implement and is thus only recommended for data warehousing. Its cost is due to offering the highest level of redundancy and performance. Despite the added cost, RAID 50 is a good solution for mission-critical networks because, depending on the drive, it can survive multiple hard drive failures. RAID 50 is a combination of RAID 5 and 0. It comprises both parity and disk striping across multiple drives. RAID 50 is applied across two RAID 5 arrays with data striped across both disk arrays. RAID 50 breakdowns the data into smaller blocks and then stripes the blocks to each RAID 5 raid set. 
821Lesson 29: Introduction to Video Adapters
82229.1 Video Adapters
823The video adapter is an expansion board that plugs directly into a computer's main logic board. Current video cards typically have their own slot on the motherboard reserved exclusively for the video card. 
824 
825A video adapter (video card) translates digital data from the CPU into an analog format the video display monitor can use to display images.
826Because the video display monitor's circuitry is analog, the video adapter's job is to act as a liaison, translating and processing digital data into analog signals that the monitor can use to display the output data.
827PCI Express
828 
829Most video cards use the PCI Express (PCIe) slot(s) that have an even greater bandwidth interface to the motherboard than AGP video cards. PCIe also uses serial data transfer to allow for higher clockspeeds, and can simultaneously transfer data in both directions. 
830Scalable Link Interface
831 
832Scalable Link Interface (SLI), an nVidia technology, uses the PCIe architecture to allow video card and motherboard manufacturers to offer the ability to add two or four PCIe video cards in parallel in a single motherboard. This lets the video cards team up and power the graphics output together, ideally at twice the speed. The graphics cards and motherboard must support SLI, and the operating system must be 32 or 64bit Windows XP or Linux. Another similar product is ATI's Crossfire. 
833 
834Lesson 29: Introduction to Video Adapters
83529.2 Major Video Adapter Components
836All video adapters in use today have four major components that collectively function to generate a video display: 
837•	Graphics Accelerator 
838•	Video Memory or Video RAM (VRAM) 
839•	Video BIOS 
840•	RAMDAC 
841Graphics Accelerator
842 
843A graphics accelerator is a high-performance adapter providing hardware support to help increase speeds of 2D displays, 3D displays, and other video operations. Support provided by the graphics accelerator reduces the CPU's work load.
844 
845Graphic accelerators commonly provide the following basic support: line draw and pixel block, texture mapping, color space conversion, and hardware scaling. Many other functions can be added depending on the cost of the video accelerator. When more functions are handled by the video card the CPU is free to do other work.
846Video Memory
847 
848Video cards are almost like a small computer with a very specific purpose. The accelerator chip processes data like a CPU. Video cards have a BIOS for basic operations. They even have memory (RAM) installed on the card.
849 
850Video memory is a collection of memory chips for temporarily storing the information a monitor displays. Like RAM, video memory functions as the video adapter's working memory—its "scratch pad." They even have a data bus that carries data to and from the memory and accelerator. In fact, video cards feature some of the most advanced data buses available. 
851The data bus in advanced desktop PCs may run at 1000Hz, transferring 64-bits at time. Advanced video cards feature 512-bit data buses running at more than 2GHz. Most use Double Data Rate (DDR) memory for even more performance.
852Increased memory is especially useful for boosting the performance of systems running high-definition, graphics-intensive software. Upgrading video cards with memory chips to improve card and monitor capabilities is no longer as common as it was previously because modern video cards supply high capability display function.
853Most video cards use GDDR SDRAM, but many different memory technologies have been used in the past. 
854The latest version is GDDR-5.
855 Editor's Note
856Though SGRAM is a form of DRAM and SGRAM is commonly used for video memory, DRAM may not be considered to be a type of video memory on industry certification exams.
857VRAM	Video 
858memory	Dual-ported	Older memory format 
859Formerly high-end video cards
860WRAM	Speeds up 
861Windows OS	Dual-ported	More bandwidth and less expensive than 
862VRAM
863
864MDRAM	Video 
865memory	Single-ported, supports interleaved memory	Almost as fast as dual-ported DRAM, 
866SGRAM
867SGRAM & 
868DDR 
869SGRAM	Video 
870memory	Single-ported	Almost as fast as VRAM, but less expensive
871FPM DRAM	Main 
872memory	Memory bits accessed through row and column coordinates	Obsolete
873	Video 
874memory		
875SDRAM & DDR SDRAM	Main 
876memory	Synchronized with CPU clock, eliminates wait states	Supports interleaved memory
877	Video 
878memory		
879EDO DRAM	Main 
880memory	Improved FPM DRAM with enhanced access speeds to memory locations	Obsolete 
881Not efficient at bus speeds greater than 
88266MHz
883	Video 
884memory		
885Types of Video Memory
886Video BIOS
887 
888When SVGA technology became an industry norm, video BIOS implementation incompatibilities led to the development of a standardized video BIOS.
889 
890•	Non-Video Driver Systems 
891For computers running operating systems that do not have specific video card drivers, the video 
892BIOS provides a set of limited video functions for software programs to access the video hardware. 
893In non-video driver systems, the video BIOS is the governing logic circuit allowing graphics software to interface with the video chip set, much in the same way a system BIOS interacts with a motherboard chip set. Specific video card drivers, designed by video card manufacturers, must be used to access the full capabilities of a video card.
894•	Video Driver Systems
895In systems with specific video drivers, video card functions—displaying application graphics—are managed after boot up by the video card driver: customized software for controlling the video card's sophisticated capabilities.
896 Editor's Note
897In operating systems with specific video card drivers—virtually all Windows operating systems—the video BIOS is responsible for rudimentary video card tasks as the computer is booting up. Once the computer has booted up completely and the operating system's drivers takes over video function, video BIOS responsibilities conclude.
898Which of the following are considered to be types of 
899 
900Random Access Memory Digital-to-Analog Converter 
901 
902Older video adapters used a Random Access Memory Digital-to-Analog Converter (RAMDAC) separate from the graphics accelerator to support analog CRT monitors. Today's RAMDAC chips are part of the graphics accelerator.
903The display information is stored and manipulated in the video memory in standard binary 1 and 0 code. 
904Binary bit patterns control the resolution and color of each pixel on a monitor's display screen.
905 
906A Random Access Memory Digital-to-Analog Converter (RAMDAC) chip reads the video memory contents, converts memory content to an analog signal, and sends the converted signal over a cable to the video monitor. All Modern LCD displays, plasma displays and TVs use digital signals rather than analog and do not require a RAMDAC. To support older CRT monitors, many video adapters come with a VGA port as well as a DVI port. If not, and the display supports one but not the other, adapters will allow either monitor type to be used.
907 
908 Editor's Note
909As DVI, HDMI or other technologies become more mainstream, The "DAC" part of RAMDAC will likely become obsolete.
910
911Lesson 29: Introduction to Video Adapters
91229.3 Pixels and Resolution
913The displayed image you finally see "onscreen" when the four video card components—video chip set, video memory, video BIOS, and RAMDAC—have concluded their work is an image made up of pixels and defined by resolution.
914The basic element of every video image is a pixel (dot). Hundreds of thousands to millions of pixels comprise what you see displayed on a video monitor. Every dot has a location reserved in video memory. 
915The maximum number of dots which can be displayed relates to the resolution. 
916The onscreen image's resolution is its degree of sharpness.
917Resolution 
918 
919Resolution is commonly expressed as a pair of numbers. Each pair of numbers represents the maximum possible number of dots on a horizontal axis and the maximum possible number dots on a vertical axis. 
920Basic VGA 640 X 480 resolution means that there are 640 possible dots on each line displayed on the screen's horizontal axis and 480 possible lines composed of dots on the vertical axis. A resolution of 640 x 480 shows 307,200 pixels on the screen. XGA expanded upon VGA by supporting two additional resolutions that improved color greatly:
921•	800 x 600 pixels (65,536 colors) 
922•	1024 x 768 pixels (palette of 256 colors) 
923Although Super Video Graphics Array (SVGA) was originally intended as another VGA extension, it evolved into a separate standard. SVGA generally refers to a resolution of 800 x 600 pixels but it can refer to a resolution of 1024 x 768 pixels.
924Ultra eXtended Graphics Array (UXGA) is being utilized for fullscreen monitors with its resolution of 1600 x 1200 pixels, making it four times the resolution of SVGA. For smaller displays (most commonly used on 1415 inch LCD laptop screens) SXGA+ has a resolution of 1400 x 1050 pixels.
925Available in high end LCD televisions and computer monitors, Widescreen Ultra eXtended Graphics Array (WUXGA) offers a display resolution of 1920 x 1200 pixels (showing 2,304,000 pixels on screen) with a 16:10 aspect ratio. 
926 
927 Editor's Note
928SVGA has a resolution of 800 by 600 pixels. XGA has a resolution of 1024 by 768 pixels. The higher the resolution, the sharper and clearer the image will be. Also, the higher the resolution, the more memory is required to draw an image. 
929 
930WQXGA (2560 x 1600) was first introduced in 2010 for home theater projectors. In 2012 Google introduced their Nexus tablet featuring WQXGA resolution, which at the time, the highest resolution available was the Apple iPad 3's QXGA (2048 x 1536). Many manufacturers produce monitors capable of WQXGA in 27-30 inch. WQXGA requires more bandwidth than one DVI can provide, therefore dual-link capable cables and devices are necessary. 
931 
932WQUXGA (3840x2400), the maximum resolution supported by DisplayPort 1.0, may require multiple DVI connectors either from the same graphics card, different graphics cards, or even different computers.
933Color Depth
934 
935When an image is displayed in color (or grayscale), a certain number of bits must be assigned per dot (per pixel) to achieve a given color depth or possible number of colors. The more bits that are assigned for each pixel increases the quantity of colors that it can display. The number of colors that each pixel can display is known as color depth.
936Bits per Pixel	Color Depth per Pixel - Known as: 
9374 bits 	16 colors - Standard VGA
9388 bits 	256 colors - Super VGA
93916 bits 	65,536 colors - High Color
94024 bits 	16,777,216 colors - True Color
94130/36/48 bits 	One Billion + colors - Deep Color
942Bits for Color Depth
943Apple's Retina Display
944 
945Apple uses the Retina Display brand name for screens that possess a pixel density that is high enough so the human eye is not able to detect individual pixels from abnormal viewing distance. Products that utilize the Retina display include the iPad Air, iPhone, iPod Touch, iPad, iPad Mini and MacBook Pro. The Retina quality can differ depending on the size of the display. Higher pixels per inch (PPI) for smaller displays and lower PPI for larger displays: 326 PPI for the smallest devices, 264 PPI for mid-sized devices and 220 PPI for larger devices. With a Retina display, each user interface widget is doubled in width and height to make up for the smaller pixels and this mode is referred to HiDPI mode. With a Retina display, pixels-per-degree (PPD) takes into consideration the screen resolution and the distance from which the device is observed. 
946The onset for a Retina display begins at the PPD value of 53 PPD. The PPD parameter is not an absolute parameter of the display like the pixel resolution. PPD depends on the distance between the display and the eye of the person looking at the display. If the eye moves closer to the display, the PPD will decline. 
947Likewise, if the eye moves away from the display, the PPD is increased proportionately to the distance.
948Lesson 29: Introduction to Video Adapters
94929.4 The Evolution of Video Adapters
950Video cards are a good watermark for charting the evolution of computers. Video displays are what people remember the most about computers. In the 1980s the Atari game system burst on the scene with color, low-resolution graphics, but it was quickly superseded in popularity by the Commodore 64 and Apple computers, which had better, higher resolution graphics. Since then video adapter design reflects the cutting edge graphics solutions from one year to the next.
951This lesson will outline this evolution and explain the technology behind it.
9521981
953 
954IBM, a company whose name is synonymous with personal computers, was first on the scene with the monochrome display adapter and (later that year) color graphics adapter (MDA and CGA respectively).
955As its name implies, the MDA was a black-and-white adapter that boasted a resolution of 720x350. Besides being limited to black and white, the MDA also could not display graphics. The MDA was adequate for its needs, which were primarily word-processing and other basic office applications.
956The CGA adapter, also released in 1981 was a step up from the MDA because it offered users more flexibility. Besides giving users a maximum of four colors (16 were available, but only four could be used at a time), the CGA adapter also gave users the option of working in either alphanumeric (A/N) or all points addressable (APA) mode for graphics. Regardless of which mode was chosen, the CGA adapter and its maximum resolution of 640x200 (when using two colors) or 320x200 (when using four colors) still left a lot to be desired when compared with today's adapters.
9571984
958 
959In 1984 IBM introduced the Enhanced Graphics Adapter (EGA). Despite its high cost, these adapters proved to be a nice improvement over the CGA. Most notably, the EGA was capable of displaying 16 colors at once and producing a maximum resolution of 640x350 pixels. The EGA adapter was also very flexible, for example it could be used with older monochrome monitors, or newer monitors, capable of taking advantage of the card's enhanced capabilities. It could also be upgraded to recognize up to 1,024 characters, as opposed to the CGA's 256 character ceiling. 
960Although this was a nice improvement, there was still a lot to be desired. Backward compatibility with software and hardware was imperfect and required constant tweaking. EGA's high price magnified this shortcoming, prompting a lot of users to stick with their older CGA adapters.
961The Professional Graphics Adapter (PGA) was also a 1984 release and was designed to accommodate the graphics needs of engineers. At the time of its release, the PGA cost as much as a car (about $5,000), which explains why it never really became popular. Despite its lack of popularity, the PGA made a significant contribution to the video adapter: the PGA was the first adapter to feature its own processor. This advancement gave the PGA the ability to display animation.
9621987
963 
964Between 1984 and 1987, video adapters made significant strides in both quality and cost. The most significant improvement was the Video Graphics Array (VGA), developed by IBM. The VGA was far more popular than any other previously released video adapter. In fact, IBM released two other video adapters in 1987: the 8514/A and the multi-color graphics array (MCGA), which were quickly discarded when it became apparent how much more popular the VGA was. VGA adapters are capable of displaying 256 colors at a resolution of 320x200 pixels, or 16 colors at a resolution of 640x480 pixels.
965VGA was the last video standard to garner industry-wide acceptance. VGA's color and resolution specifications became the video industry's common denominator. This meant that all subsequent video adapters were designed to support VGA's specifications. VGA has support in BIOS, eliminating the need for drivers (they are part of the BIOS). However, video cards released after VGA (including all modern video cards) require proprietary drivers to access the card's specific enhanced features. 
966 Editor's Note
967The video game industry is generally the driving force behind improving graphic capabilities in computers. The video card industry has reaped the benefits of increased consumer demand for games with detailed, high-resolution graphics. Look for continuing growth in the video card industry to coincide with the popularity of video games.
9681990s
969 
970The 1990s marked the modern age of computing (of course this watermark changes every five to 10 years) and there was no better piece of hardware to represent this than IBM's XGA display adapter. The newest link in a chain of video enhancements, the XGA was built from VGA technology and boasted 32-bit bus mastering. Bus-mastering, a new technology in 1990, gave the XGA the ability to process graphic demands without having to go through the computer's CPU.
971Besides bus-mastering, the XGA adapter was capable of more colors at higher resolutions than any preceding card. The XGA could display up to 65,536 colors at a resolution of 640x480 or 256 colors at a resolution of 1,024x768.
972Despite these improvements, XGA and XGA-2 (1992) were not popular because they were very proprietary technologies and didn't mesh well with products designed by other companies.
973The success behind the SVGA is its flexible nature. SVGA was not designed by IBM, but rather by independent manufacturers, trying to create a better quality, universally accepted video adapter. SVGA does not refer to a specific video card or video card specifications, but rather to many different kinds of video cards that offer a range of colors and resolutions. Despite their differences, both SVGA and VGA adapters use the same DB-15 connector.
974and Beyond
975 
976Improvements in video cards during this decade primarily focused on improving 3D algorithms and clock speeds. Two companies have emerged as rivals in this market: ATI and Nvidia. To render enhanced 3D graphics, both have developed specialized graphics processing units (GPUs) that are embedded in CPUs. 
977Modern computers can have a GPU on its video card or on the motherboard.
978Gaming demands have largely driven the market for high level graphics and performance. Early in the decade ATI introduced its Radeon products that supply graphics for Nintendo (GameCube and Wii) and Microsoft’s Xbox 360. Nvidia’s product lines include GeForce, used in a number of gaming applications.
979 
980Nvidia was the first to launch DirectX 10 video cards in late 2006, based on Compute Unified Device Architecture (Cuda); these cards were the GeForce 8800GTS and GeForce 8800GTX.  The CUDA line grew to include the GeForce 9 series and eventually to the GeForce 200 series (the flagship card being the powerful dual GPU card GTX 295 that was launched in early 2009).  The GeForce 200 series includes physically huge cards with even greater performance over the previous 8 and 9 series lines. All of these cards support Nvidias Scalable Link Interface (SLI) technology, allowing multiples of the same card to be run in one system to enhance performance.
981ATI released their first DirectX 10 cards shortly after Nvidia with its Radeon series, the most powerful card being the Radeon HD 3870.  To match the Nvidia GeForce 200 series ATI launched the Radeon HD 4000 series.  In late 2009 ATI stepped out ahead of Nvidia by releasing the first set of DirectX 11 video cards with the highest performing single GPU card being the Radeon HD 5890.  ATI released another powerhouse with its Radeon HD 5970, which is the first dual GPU DirectX 11 card and is easily the company’s flagship card.   These cards are massive in size and support ATI's CrossfireX technology, allowing for multiples of the same card to be run in one system to enhance performance.
982Lesson 30: Video Display Monitor
98330.1 Video Display Monitors
984Usually called simply the "monitor," a display monitor is a computer system's output peripheral device. The monitor's job is to present, on a screen, output from a computer, camera, VCR or other video generator. 
985 
986Essentially, the display monitor takes the output from the video card and displays the output according to the RAMDAC chip's instructions. 
987Digital Monitor
988 
989The first generation of digital monitors offered text-only displays and were called monochrome display adapters (MDA). In 1982, Hercules Computer Technology produced a monochrome graphics adapter—Hercules—the first digital adapter capable of graphic displays. 
990The first digital monitors offered high resolutions, but even the Hercules could only offer black and white. Color Graphics Adapters (CGA) were the next generation in video cards, doing what no other video card had done: offer color graphics displays. With the CGA, IBM led display technology development and continued to lead with their updated Enhanced Graphics Adapter (EGA). 
991Subsequent adapters all provided adequate colorized graphic displays. However, even the EGA could not display more than 16 colors. In fact, it was not until analog monitors were developed that more advanced color palettes were available to users.
992Analog Monitor
993 
994In 1982 IBM designed the analog monitor as an accessory to their new PS/2 line of computers.
995Analog displays, which could produce more color gradations than digital displays, were more appealing to the human eye. Called the VGA or Video Graphics Array, this analog display standard eventually replaced earlier standards such as Monochrome Display Adapter (MDA), Color Graphic Adapter (CGA), and Enhanced Graphics Adapter (EGA). Subsequently, VGA became the basis for all video display technology.
996 Editor's Note
997The reason IBM chose to use the analog display format was the company discovered analog displays could show more gradations of color than a digital display. Studies have shown that color gradation is more important to human perception than resolution, therefore, IBM chose to use an analog display system.
998IBM continued to develop the VGA adapter along their proprietary lines. However, competitors soon created their own advanced implementations, generally called Super VGA or SVGA. Since SVGA is not an official standard, drivers must be created by each manufacturer for each of these cards. 
999Early Video Adapter Evolution	
1000Video Adapter 
1001Type 	Graphics 	# of Colors 	Type of 
1002Monitor 
1003MDA 	No 	2 (black and white) 	Digital 
1004Hercules 	Yes 	2 (black and white) 	Digital 
1005CGA 	Yes 	16 	Digital 
1006EGA 	Yes 	16 	Digital 
1007VGA 	Yes 	256 	Analog 
1008SVGA 	Yes 	256-16.7 million 	Analog 
1009 Editor's Note
1010Test Tip: Although SVGA is not an official standard, the term SVGA is used to refer to a resolution of 
1011800 x 600. VGA refers to a resolution of 640 x 480
1012
1013Lesson 30: Video Display Monitor
101430.2 Video Display Technologies
1015Two common video display technologies are CRT and LCD. CRT (cathode ray tube) may be found in legacy desktop PCs. Now standard technology, LCD (Liquid Crystal Display) is used in laptop computers and flat screen monitors.
1016CRT
1017 
1018A cathode ray tube (CRT) is a vacuum tube used as a display screen in video monitors or television sets.
1019In the past, the term CRT referred just to the display screen. Today, the term CRT usually refers to the entire monitor, not just the tube itself. More commonly, the entire device is simply called the "monitor."
1020LCD
1021 
1022A liquid crystal display (LCD) is a modern display technology using rod-shaped molecules (liquid crystals) that possess liquid qualities and can bend light. 
1023When the liquid crystals are in a neutral unexcited state, the crystals direct light through two polarizing filters, permitting a natural background color to show through.
1024When energized, the crystals redirect light to be absorbed in one of the polarizing filters, causing a dark appearance in certain crystals. The contrast between energized and un-energized crystals defines shapes and graphics.
1025 
1026LCD displays are lighter than CRTs, more energy efficient, and free of geometric distortion, which can cause flickering and other display hindrances. 
1027 Editor's Note
1028Flat panel systems should be viewed from directly in front of the screen. Images can appear fuzzy, dim, and indistinct when viewed from an angle.
1029Liquid crystal display screens became standard in portable computer systems for a variety of reasons. The LCD monitor is lightweight, produces very low glare, and has very low power requirements. Some LCD screens require as little as five watts of power for operation.
1030LED Verses LCD Backlighting
1031Backlighting refers to the method used by the LCD display to illuminate the pixels. LED-backlit LCD displays use a series of LEDs for it's source of illumination while other LCDs use a series of fluorescent tubes. LED-backlit displays have an advantage over other LCDs' picture quality while being thinner and lighter and also marketed as being more energy efficient. 
1032LED-backlit displays use one of these types of systems:
1033•	Edge-lit: most LCDs are edge-lit without local dimming with its LEDs placed along the panels edge. Local dimming is a feature that enhances black levels by making them darker. 
1034•	Full array: delivers the highest level of picture quality. Rows of LCDs cover the entire LCD panel. Full array LCD displays feature local dimming of individual groups of LEDs to enhance the blacks. Full array backlit displays are slightly larger and heavier than edge-lit displays and are generally more expensive.
1035Monitors and Projectors
1036 
1037Organic LED (OLED) displays are thinner and lighter than LED display and use a layer of organic material that responds to electrical stimulus to emit light, which enables each pixel to light individually and as a result, much deeper black levels than LED.
1038A Plasma display is flat panel monitor that possesses high levels of brightness, deep black levels, and a very wide range of colors are typically used in home theater applications because of their accurate representation of video. Plasma displays use of tiny cells of ionized gas that light up when stimulated by electricity and can be up to 150 in (381 cm) or more.
1039Digital Light Processing (DLP) projectors use a spinning color wheel with a microprocessor-controlled array of mirrors called a digital micro-mirror device (DMD). Each mirror corresponds to a specific pixel and reflects light toward or away from the projector optics, which creates a monochromatic image of up to 1024 shades of gray in between white and black. Lastly, the color wheel adds the color data to finish the projected color image. 
1040Touch Screens
1041The iPads operating system features a specialized interface. Built originally for mobile phones with a finger driven "multitouch" interface, multiple simultaneous finger touches are recognized, allowing for enhanced user manipulation. 
1042Over the decade, there have been as many variations as there are manufacturers, regarding their construction.
1043The most common types of Tablet PCs are:
1044•	Slates have only onscreen virtual keyboards. They resemble a clipboard and are often used in health care, education, and field work. 
1045•	Booklets are composed of two multi-touch screens that fold together like a book. Booklets are designed for use as digital day planners, e-readers, Internet access, and multimedia.
1046Convertibles closely resemble laptops with a flip-around screen which folds over the standard keyboard. 
1047Tablet PCs now refer to any tablet-sized personal computer regardless of its operating system.
1048Touchscreens usually are one of two types:
1049Resistive touchscreens are very precise, and usually require a stylus or fingernail. Resistive screens are less capable of implementing multi-touch technology.
1050Capacitive touchscreens are less precise, but more responsive. A conductive material is needed for input, like a finger tip or a stylus with a special tip. Most use multi-touch screens. 
1051Lesson 30: Video Display Monitor
105230.3 How Display Monitors Work?
1053Monitors can be very complex pieces of hardware. Their ability to display high resolution graphics came about after years of experimentation. The following section explains how CRT and LCD monitors work.
1054LCD (Liquid Crystal Display) Monitors
1055 
1056For a long time CRT monitors have been the only type of monitors that were used with personal computers. But, like most other types of hardware, improved technology has led to better quality. Thus, CRT monitors are now legacy. 
1057LCDs have become standard; they feature high resolution images, are lightweight, and do not require a picture tube. They provide an easy to read, energy efficient, flat screen that significantly cuts down on glare. LCD monitors also take less space because they do not have a tube like legacy CRT monitors and televisions. 
1058 
1059Despite the fact that the first LCD monitors were not created until 1968, LCD technology began as a very basic experiment in the late 1800s. It had been observed that liquid crystals (which are derived from cholesterol) have some very unique characteristics. More specifically, liquid crystals display qualities of both liquid and solid. Liquid crystals are actually rod-shaped molecules that can twist and untwist when they are stimulated with electricity. When a light source is added to this equation, the liquid crystals can open to let light through and close to keep light out—just like window blinds. 
1060Liquid crystal displays are more complex than the simple explanation above but they are built on the same scientific foundation of knowledge. There are two types of LCD monitors: passive matrix and active matrix color. 
1061	•	Passive Matrix LCD 
1062Passive matrix monitors are fairly simple to understand. In a passive matrix display the screen is divided into a grid with both horizontal and vertical coordinates (columns and rows). There is one layer of glass for each axis (columns and rows) that has either horizontal or vertical gridmarks outlined by a conductive metal (usually indium tin oxide). When the two pieces of glass are pressed together the screen is broken down into a matrix of columns and rows, that can be differentiated by a unique coordinate.
1063Before the two pieces of glass (called substrates) are put together, the liquid crystal material is sandwiched between. Next, a polarized film is attached to the outside part of both glass pieces. In order for the display to work, a fluorescent light source is placed either above or behind the LCD mechanism. 
1064 
1065When electricity is applied to the LCD, current will proceed to the appropriate grid coordinates, lighting up that region of the screen.
1066Passive matrix monitors are very efficient but they have two notable drawbacks, poor response time and poor voltage control. The poor response time problem is evident when a screen's display is hampered by "ghost" images or images that should be erased but are still slightly noticeable. 
1067When electric current is run to a specific coordinate on the LCD's grid, it can affect the adjacent coordinates, resulting in imperfect images. Despite these drawbacks, passive matrix technology is still popular and used in computers throughout the world.
1068	•	Active Matrix LCD
1069Active matrix displays are a step up from the passive matrix displays discussed above. Active matrix displays rely on thin film transistors (TFT) that are arranged in coordination with the screen's grid intersection points. Each thin film transistor is a small switching transistor and capacitor. These components work together to capture, then regulate and hold a charge over a specific screen coordinate. 
1070 
1071Because the voltage can be regulated, the liquid crystals can be opened and closed with great precision, allowing for lighter and darker shades of the same color (remember, when voltage is applied to the liquid crystals, they open. The more voltage that is applied, the more the liquid crystals will open, and vice versa). Active matrix displays are better because it is easier to control the flow of electricity to each coordinate of the screen. Additionally, each capacitor can retain a charge so images have better resolution. 
1072Color LCD Displays
1073Up until now we have only explained the technology behind monochrome LCDs. Monochrome LCDs are capable of displaying 256 different shades of gray, however, in order to display colors the LCD must have blue, red, and green pigmented sub-pixels for each coordinate on the screen grid. 
1074Take an active matrix display for example, with a resolution of 1600x1200 (remember, this means there are 1600 pixels going across the screen and 1200 pixels going up and down). If it were monochrome, there would need to be a transistor for each pixel (1600 Rows x 1200 Columns) bringing the number of transistors to 1,920,000. In order to enable color, there would need to be a transistor for each sub-pixel (1,920,000 Pixels x Three Sub-Pixels) bringing the total number of transistors to 5,760,000.
1075Because of the sheer number of transistors required for a color active-matrix display, it is common for these types of displays to have "bad" pixels. Creating this complex a display will become more precise over the next few years, but until then they will remain very expensive.
1076 
1077Lesson 30: Video Display Monitor
107830.4 Choosing a Video Display System
1079Since nearly all the communication between a computer and user takes place via a display system, the display adapter and monitor chosen can have a significant impact on the computing experience. As a rule, more colors, higher resolution and higher refresh rates result in slower video adapter operation. Higher settings use more memory and processing power; so you may notice slower graphic drawing on the monitor. 
1080When you need more colors and faster drawing, think about installing a video card with more memory and a faster graphics accelerator. A video card may also have more than one video display connector to enable using multiple monitors. There are also motherboards that can support multiple video cards. 
1081Since display adapters can be quite expensive, it is important to accurately gauge your display needs. If you don't foresee tapping an expensive, high-end card's potential, a less-expensive card will likely suit your needs at a more economical cost.
1082 
1083Maybe utilizing more than one monitor would be worth the extra investment, provided the video card and motherboard can support that feature. With a second monitor you can add extra work space, or use it as a projector for presentations. Using the second monitor as extra workspace is a common setup. This allows the user to spread windows across both monitors, essentially doubling the workspace. One consideration though, is once you've used dual monitors for that purpose, you won't want to go back. 
1084Listed below are some factors to consider when choosing a video display system.
1085Digital Video Interface (DVI)
1086CRT monitors have used the DB15, or in some cases BNC cables that transmit signals in analog. 
1087LCD monitors are digital, and thus should use the DVI interface to interface with the video card. Having a pure digital interface to a digital display (an LCD monitor) allows for precise graphic output that isn’t prone to electronic interference and produces an accurate picture.
1088 
1089Display Connector Type:
1090•	Digital Visual Interface (DVI) - 24 pins for digital signals and 4 pins for analog signals
1091•	DVI-I - used for both analog and digital signals
1092•	DVI-D - only handles digital signals 
1093•	DVI-A - only handles analog signals
1094•	DB-15 - has 3 rows and 15 pins and is commonly used for analog video.
1095•	BNC (Bayonet Neill–Concelman) connector - connect coaxial cable to devices using a quarter-turn connection scheme and used with digital or analog audio or video.
1096•	RCA connector - has a central plug with a ring around it and can be used to carry audio or video and the connectors are groups of three: a yellow connector carries video and a pair of red and white connectors carry left and right channel audio
1097The following display cables transfer video signals from the computer to display devices:
1098•	Component/RGB - Carries analog video signals over three shielded cables (red, green, blue) 
1099•	Composite - Carries analog audio or video signals.
1100While some inexpensive LCD monitors might come with only a DB15 for backward compatibility and economic reasons, this leads to an digital-to-analog, then analog-to-digital conversions that while being more complicated also leads to the same interference problems that exist with standard analog CRT monitors.
1101 
1102All digital video interfaces found on devices used today other than DVI will be one of the flowing: 
1103•	HDMI integrated digital video and audio into a single cable making it useful for connecting personal electronics such as camcorders, video game consoles and PCs. HDMI is 
1104backward compatible with DVI's improved clarity and color over the previous VGA standard (with the exception of DVI-A).
1105•	DisplayPort video and audio connector have the ability to connect up to 4 monitors over a single connection. DisplayPort was developed by Video Electronics Standards Association (VESA) to replace, while still having backwards compatibility via adapter dongles for VGA and DVI.
1106•	Mini DisplayPort is a miniaturized version of DisplayPort developed by Apple specifically for their computers. Capable of supporting resolutions up to 2560 x 1600, it is now used by other PC notebook manufacturers. With the proper adapter, Mini DisplayPort may be used to drive VGA, DVI, or HDMI interface displays. 
1107•	Thunderbolt was developed in collaboration with Apple and Intel as a successor to Mini DisplayPort. Thunderbolt adds support for PCI Express and maintains backward compatibility with peripherals that are Mini DisplayPort based.
1108Monitor Size and Resolution
1109Basically, a monitor needs to fit into your workspace and be capable of supporting commonly used graphics software. A monitor's resolution—how many pixels are displayed on the screen—is highly important in determining how sharply graphics are presented onscreen. The higher the resolution, the larger the viewing area, and the "better" the image. A 1280 x 1024 resolution serves some users well. Other users' needs will be satisfied only by larger, higher resolution 1600 x 1200 or even 2880 x 1800 displays.
1110Native resolution
1111Native resolution has the same number of pixels that the monitor has.  Change the display settings with the Display Settings utility and change the appearance of the desktop by modifying the resolution and color quality. Change more advanced display settings, such as the wallpaper, screensaver, power settings, and other options:
1112•	In Windows 7: Start > Control Panel > Display > Change display settings
1113•	In Windows Vista: Start > Control Panel > Personalization > Display Settings
1114•	In Windows XP: Start > Control Panel > Display > Settings Adjust the following features in Windows 7:
1115•	Screen resolution
1116•	Orientation 
1117•	Refresh rate
1118•	Display colors
1119Access the display settings in Windows 7 and Windows Vista in the Display link of the Personalization control panel utility.
1120Widescreen
1121Because display monitors are used for entertainment purposes, as well data processing, widescreens have become the mainstream standard for computer displays. Though movie watching and gaming popularized widescreen displays, a more practical reason may be their ability to fit two standard letter sized pages side-by-side, aside from the extra desktop area they offer. 
1122 Editor's Note
1123Aspect ratio is defined as the ratio of width-to-height of the display in this case. It is expressed as two numbers separated by a colon (x:y). Displays with the aspect ratio wider than 4:3 are considered widescreen. The larger the resulting fraction or the greater the value between the numbers, the wider the display is. Newer monitors mostly use a 16:10 or 16:9 widescreen aspect ratio. The 16:9 is typically used for HDTVs.
1124Today's flat panel televisions sport resolution ranges close to, or at computer monitors ranges. Most consumer televisions support 1080p which is an HDTV term for high definition video - meaning 1080 lines of vertical resolution. A 1080p HDTV is equivalent to 1920 x 1080 resolution. Most consumer televisions being sold today supporting full high-def resolutions are equipped with ports supporting 1080p such as HDMI.
1125Number of Colors 
1126The number of colors displayed on a monitor will determine much of what you see onscreen. The standard number of colors displayed on monitors ranges from 16 to 256 to 65K (65,000), and up to 16M (16 million).
1127Most modern multimedia applications require a minimum of 65K colors. Applications displaying realistic photos or full motion video may require 16M colors. More standard application such as word processing and spreadsheets function fine using only 16 or 256 colors.
1128Display adapters with drawing functions significantly increase the speed with which images are displayed onscreen. Drawing function inclusion on display adapters is known as a "graphics accelerator," and no modern video card should be without one. Video cards should also feature video acceleration which supports full-motion video operability.
1129Contrast Ratio
1130The ratio is the equivalent to the brightness of the white level divided by the brightness of the black level of the LCD monitor. The higher the ratio the better. (example would look like 5000:1 contrast ratio)
1131No standardization for this measurement exists, so it is at the discretion of the LCD panel manufacturer to report this number. Due to obvious discrepancies, it is best to read reviews and compare LCDs first hand before making a big purchasing decision. 
1132Pixel Response time
1133Measured in milliseconds (ms) it is a measure of how long an LCD display takes for a liquid crystal cell in the display to go from black, to white, and then back to black again. The lower the number the better animation, video, and games will run on the LCD. A high pixel response time will cause picture tearing, running, or other such undesirable output.
1134Again, no standardization for this measurement exists, so it is at the discretion of the LCD panel manufacturer to report this number. Because these discrepancies obviously occur, it is best to read reviews and compare LCDs first hand before making a big purchasing decision. 
1135Viewing angle
1136If a computer user views an LCD at too great of an angle the picture will seem blurred, darker, or completely black. Given in degrees this shows how much of an angle you can view the screen at without any deterioration. Unless there is some reason you don't want others around you to be able to see your monitor, the higher viewing angle is preferred.
1137Power Management
1138In this day and age it is important to be conscious of any and all energy-saving strategies and practices. There are still a lot of organizations whose users leave both their computers and monitors running at all times of the day and night, including lunch breaks and after leaving the building for the day. Surely any energy conscious individual would see that this is clearly a waste of electricity. Fortunately, a lot of computer and monitor manufacturers are building their hardware to be energy efficient.
1139 
1140Power saving monitors, denoted with the Energy Star compliance certification are one of the best tools that an IT department can use to combat frivolous wastes of electricity. Energy Star compliant monitors feature sleep mode and standby/sleep mode options to help users conserve energy. 
1141Compliant monitors will simply turn off after a specified amount of time if there have been no keystrokes or mouse movements. In order to turn the monitor back on, a user has to either move the mouse or enter a keystroke.
1142Privacy and anti-glare filters
1143Privacy and anti-glare filters can be added to a monitor. With a privacy filter, only the user and people directly behind the user are able to read the screen and people to the side of a monitor are prevented from reading information on the screen. An anti-glare filter makes it much easier to read the screen in the daylight or when a light is behind the user and can be attached to the screen and helps prevent the glare of the sun and bright lights from reflecting off the screen. 
1144Power Supply and Cable Interface
1145 
1146A monitor's power supply converts and delivers power to a monitor's internal components. Most monitors connect directly to an AC power outlet. A monitor's power supply functions similarly to a computer's power supply. 
1147The cabling interface makes up the connection and interaction between hardware, software, and user. The interface also acts as the data path between the computer and the monitor, supplying a monitor with data for graphics, images, and instructions.
1148 
1149 
1150Lesson 30: Video Display Monitor
115130.5 Video Display Troubleshooting
1152Because the display is such an essential component, most operating systems now automatically install drivers and choose basic settings such as screen resolution, refresh rate, and color, based on the monitor. If you want to change the settings to something other than what was originally assigned, resolution for instance, then you must access the control panel's display settings. Follow the simulation below to access Windows 7's display settings.
1153 
1154Accessing the Display Settings Panel
1155in Windows 7.
11561.	Step One: Click on the Start button → Control Panel
11572.	Step Two: From the Appearance and Personalization group, choose Adjust screen resolution
1158An easier way to access the control panel is by right-clicking the desktop and choosing Resolution. If you have a video adapter installed, it most likely came with its own drivers and may also include it's own utility console. These third party utilities may also provide their own shortcut on the same menu accessed from the desktop. Depending on the adapter, special features or enhancements such as 3D settings may be included in addition to basic display configurations such as display resolution, refresh rate, and multiple display settings. 
1159 
1160Desktop Shortcuts - NVIDIA Display Control Panel with 
1161Screen Resolution 
1162If there are problems with the display's appearance, there are some factors that can improve performance:
1163•	reduce the number of open windows and running programs
1164•	refrain from running simultaneous graphic-intensive programs
1165•	lower the resolution
1166•	upgrade to a higher quality video card
1167•	Turn off the Windows 7's Aero features
1168Some of Windows 7's Aero features such as transparent windows may be too much for some systems to handle with efficiency. In any case there is a troubleshooter program that can be used to insure the optimum settings are employed by letting Windows decide on the proper configuration. Follow the simulation below to run the Windows 7 troubleshooter: 
1169 
1170Troubleshooting Aero in Windows 7.
1171Troubleshooting: Multiple Displays
1172 
1173If an additional monitor is connected, Windows 7 will detect it, install drivers and apply settings that will best suit it. If that same monitor is disconnected, the previously used settings will be applied. Windows will remember the settings used for additional monitors, but will only configure one automatically. Any more than that will have to be initially manually configured. 
1174In Windows 7, pressing the Windows + P keys simultaneously, will launch a multiple display setup console. From here you can choose to show only the computer with no additional monitor, show a duplicate the first monitor, use both monitors as a single desktop, or show only the additional monitor.
1175 
1176Windows 7 multiple display setup console.
1177Troubleshooting: Refresh Rate
1178 
1179When inexperienced users begin making changes to critical monitor settings like refresh rate and resolution, the end result is usually a blank screen. There are two variables to focus on when confronted with this problem.
1180Unfortunately, it is possible to set the monitor's refresh rate beyond its bandwidth capabilities. When this happens, the user will either get a blank screen, a monitor error message or a nonsensical display. In any of these cases, the user should just leave their machine alone for 15 seconds and the previous settings will be restored. If this strategy does not work, it will be necessary to restart the computer in Safe Mode and return the refresh rate to its original setting.
1181 
1182Windows can be setup to keep users from being able to select refresh rates outside of the acceptable range. By checking Hide modes that this monitor cannot display, users will be prevented from selecting an inappropriate refresh rate.
1183A user changed the refresh rate on his computer, and the desktop is no longer available. What should be done?
1184A.	Replace the video adapter
1185B.	Run! 
1186C.	Call a doctor
1187D.	Press Control/ALT/Delete
1188E.	Boot up in Safe Mode
1189Troubleshooting: Resolution
1190 
1191The number of pixels on the screen (known as resolution) is directly related to the quality of the screen's display. Of course, every user would like to be able to utilize the maximum resolution capable, unfortunately it is a request not every monitor is able to accommodate.
1192As a technician it is important to be familiar with the maximum resolutions for every monitor being used—this information is available in the monitor's documentation. Unfortunately this level of familiarity is not a requirement for all users, and it is possible for users to easily change a monitor's resolution to a value beyond its acceptable limits.
1193When this happens, the strategies for returning the monitor to a working state are essentially the same as those discussed in the previous section. The user should just leave their machine alone for 15 seconds and the previous settings will be restored. If this strategy does not work, it will be necessary to restart the computer in Safe Mode and return the refresh rate to its original setting.
1194In order to help prevent either of the aforementioned errors, the system automatically tests any new settings before they are applied. If an invalid setting has been entered the user will be able to revert to the previous settings by either pressing No in the monitor settings box (pictured below), or by not pressing anything. 
1195 
1196In some cases, when new settings do not permit the screen to be visible, the monitor settings box will be present, but because it too will not be visible, after 15 seconds the screen's resolution and refresh rate will revert to their previous setting
1197Troubleshooting: Garbled Image
1198 
1199When diagnosing a monitor that is displaying a garbled image while Windows is running, the problem needs to be isolated as either a software or hardware problem. 
1200Shutdown and restart. If the text on the boot screen is clear, then most likely the monitor is fine and it's a driver issue (either a bad driver or improper settings) is mostly the cause of the problem. Boot into Windows Safe Mode to enable the generic Windows video driver and then install a new video driver or diagnose the problem.
1201If the image is still garbled, try a new monitor to see if the monitor has failed or if the video card has failed. 
1202Or connect the suspected monitor to another computer and see if the problem persists.
1203Safe Mode is an alternate boot method that makes it easier to diagnose problems. The only programs loaded in Safe Mode are the operating system and drivers for the mouse, keyboard, and a basic (generic) display.
1204Troubleshooting and Maintenance
1205 
1206The first and most important thing to know about monitors is that they can be very dangerous. Only trained professionals should ever open the monitor's case and explore its contents. The component within the case is capable of holding an electrical charge whether the monitor is on/off, or whether it is plugged in or not. 
1207There is enough electricity within the case to cause serious injury or death.
1208The best preparation for repairing a monitor is knowing when it is really broken, and when it is simply misadjusted. In some cases a monitor that appears to be broken is just improperly set and can be fixed by manipulating the monitor's settings (discussed above). When a monitor is actually broken, it is best to contact the manufacturer or the store from which it was bought. Before coming to the conclusion that a monitor is not working, eliminate any variables that may be contributing to display problems. 
1209•	Video Adapter
1210Just because the display doesn't appear properly does not mean the monitor is broken. In many cases the problem is actually with the video adapter. Like any other circuit, an adapter can succumb to common problems that occur over time. When diagnosing a bad display begin by attaching the problem monitor to a computer that is working properly. If the problem monitor works fine at a different terminal, then it can be assumed the problem is not with the monitor.
1211Another important point to keep in mind is that when an adapter malfunctions it may be an indication that there is a problem with the video adapter's driver. If possible, try installing the newest driver form the video adapter manufacturer's Web site.
1212•	Video Cable
1213Once it has been determined that the monitor is not the problem, it is necessary to determine if the problem lies with the video adapter or the video cable. This can be done by swapping video cables between a working terminal and the malfunctioning terminal. If the display on the working terminal continues to work without problems, then it is safe to say that the video cable is not malfunctioning.
1214On the other hand, if a properly working display shows a problem after the cables are swapped, then it can be assumed there is a problem with the cable. In most cases, the problem is actually with the connector. The connector has small, fragile and easily bent pins that are used to connect the video adapter to the monitor. Check to make sure each of the connector's pins are straight. If not, it is possible to straighten them.
1215Cleaning
1216 
1217With daily use, monitors can become dusty or smudged with fingerprints. There are two important factors to remember when cleaning a monitor. First, always remember to remove power from the monitor before cleaning. This will prevent potential shock to yourself or damage to the monitor. Second, use the recommended cleaning product or suggested cleaning solutions indicated in the installation manual accompanying your monitor. It is important to use the proper cleaning solvents as some contain chemicals that can damage a monitor screen. 
1218Very basic steps are required to clean your monitor; screen and casing. First for dust removal, simply use a dry micro-fiber cloth (avoid using paper towels or other items that may scratch the monitor surface). If dust is the only problem, this will suffice. 
1219Typically the screen can be cleaned with an appropriate cleaning solution with a soft cotton or anti-static lint free cloth. For anti-glare or glare-free monitors, it is recommended using only water and a damp cloth. 
1220To clean the monitor screen, spray the cleaner onto the cloth until it is damp, not soaked, and then rub the screen evenly in one direction moving from top of the display to the bottom. 
1221It is important to spray the cloth and not the monitor screen to prevent any cleaning liquid from dripping into the monitor's casing and causing damage to the monitor's electrical components. NEVER apply the cleaner directly to the screen; this is an easy way to ruin your monitor.
1222The following is a list of acceptable cleaning solutions:
1223•	Water (Tap water is acceptable but distilled is preferred) 
1224•	Isopropyl Alcohol (mixed with water)
1225•	Computer wipes (handy for fast clean ups) 
1226There are a few factors to remember when cleaning the monitor casing: 
1227•	Make sure that nothing (i.e. papers or books) has been placed on or covering the monitor's air vents 
1228•	Any obstruction to the vents could cause the monitor to overheat or catch on fire 
1229•	Never open the casing as you could seriously electrocute yourself! Leave this to the professionals 
1230To clean the monitor casing, vacuum or using a damp anti-static cloth, wipe it over the casing to remove any dust particles on the casing and ventilation holes. Then take compressed air to clean away any remaining dust particles. If you do use a vacuum, make sure that it is a small vacuum specifically designed for computers. Otherwise, using the right attachment (usually a hand held dusting brush or a Wacky Vac Vacuum Attachment), and the lowest setting, a vacuum will remove the accumulated dust particles on your monitor casing.
1231Options are limited once it has been determined that the display is actually broken. If this is the case the best course of action is to either contact the retailer where the monitor was purchased, or the monitor's manufacturer for repair information. Depending on location there may also be third-party repair outlets that specialize in fixing monitors.
1232Lesson 31: Sound Cards
123331.1 Sound Card
1234A sound card, also known as an audio card, is an expansion card that manages the input and output of audio signals to and from a computer. Typical sound card functions include recording and playing back audio files, interpreting and directing data gathered from a microphone, and preparing data for output to a set of speakers or other external amplifier.
1235 
1236Many motherboards today feature an integrated sound card within one of its chip sets. Still referred to as a “sound card”, these integrated sound systems often use the same basic components as a typical plug-in type card and are generally adequate for most users. Some enthusiasts, however, still prefer to use plug-in cards, which incorporate higher quality components and can achieve a higher quality sound. 
1237 
1238
1239Lesson 31: Sound Cards
124031.2 Sound Card Evolution
1241In the early 1980s, computers could only produce simple beeps or chirps as standard alert sounds. Not until the mid-1980s, when Creative Labs and Ad Lib Inc. separately designed the first consumer, home-user sound cards, were more sophisticated sounds possible.
1242A significant change in sound card technology came about when Creative Labs developed the 
1243SoundBlaster card in the late '80s. Monaural versions of the Sound Blaster sound cards were introduced in 1989, and a stereo version was introduced in 1992.The SoundBlaster was such a welcome advancement in sound technology, the computer industry quickly began to build motherboards and software to conform to Sound Blaster’s specifications.
1244Today, technology continues to create even greater PC audio enhancements: more realistic sound, speech recognition features, 3D sound, audio communication via the Internet, surround sound support, recording, mixing, and editing sound capabilities.
1245Modern sound cards have color coded audio connectors such as a front speaker port (green), rear speaker port (black), center speaker port (orange), microphone port (pink), and line-in port (blue). Along with standard audio connections, some sound cards may also include a game/MIDI port (yellow) and/or SonyPhilips Digital Interface Format (S/PDIF) port. The MIDI port is a dual-purpose port that is used to connect a joystick for gaming, electronic instruments or a synthesizer for music. S/PDIF facilitates the output of digital audio signals from the computer to audio components used in home theaters or other high fidelity systems.
1246 
1247Some include a front bay interface that feature a second line-in, instrument ports for recording music, a headphone jack with its own volume control, as well as other options. Having these ports in a drive bay in the front of the computer, rather than at the back, can be highly advantageous for those using the computer as a personal recording studio.
1248Like many types of hardware components, sound cards are designed to fit into either PCI Express (PCIe) or Peripheral Component Interconnect slots (PCI slots). ISA buses, once the industry standard, are no longer used for sound cards. A major disadvantage to ISA cards was their heavy reliance on a computer's CPU, which slowed a computer's overall performance. Although PCI and PCIe sounds cards are similar, an advantage to using PCIe slots is their faster data transfer rates and ability to send more data at one time via increased bandwidth channels. Many PCIe sound cards contain an on-board processor to free up the CPU.
1249 
1250PCIe Sound Card 
1251Lesson 31: Sound Cards
125231.3 How Sound Cards Function
1253Sound itself is analog, but computers see and store data in a digital form. Therefore, before a computer can even begin to process sounds of the world (i.e. from a microphone), sound data must be converted into a usable digital format. Conversely, digital code from a computer has to be reproduced into analog signals in order for audio to be heard from a speaker. 
1254Analog-to-Digital Conversion
1255 
1256To make an analog-to-digital sound conversion possible, an Analog-to-Digital Converter (ADC) is used. An ADC, usually contained within a single chip on a sound card, converts varying analog sound waves into digital signals and values. Once an ADC converts the sound to a digital code, the data is stored in a file using the Pulse Code Modulation Method (PCM). This conversion process is also called sampling.
1257 
1258Digital-to-Analog Conversion
1259 
1260When sending sound to a computer’s speakers, a Digital-to-Analog Converter (DAC) is used. During the playback of an audio file, the digital bit stream is converted to analog signals, which can then be sent to the speaker’s amplifier.
1261Sound cards use two basic methods to translate digital data into analog sounds:
12621.	FM synthesis artificially simulates a sound through mathematical calculation, and even the best FM Synthesis sounds artificial. 
12632.	Wavetable synthesis relies on stored sample recordings of real instruments, using a digital signal processor (DSP). Wavetable synthesis produces a better sound but is costlier. Most sound cards support wavetable synthesis, but the quality varies greatly between manufacturers. Even the poorest wavetable synthesis is better than FM synthesis.
1264About Sampling
1265 
1266As mentioned earlier, the basic concept of digital recording of sound is called sampling.  How well a digital sound file represents an original analog sound depends on a sound card's sample rate and its sample size.
1267Sampling rate refers to the number of sound samples made per unit of time: a high sampling rate creates a more accurate sound. The sampling frequency should be at least twice that of the analog sound being recorded. Common sampling rates range from approximately 44,100 Hz to 192,000 Hz. 
1268 
1269A large sample size is a good indicator of sound quality because it represents the number of values (expressed in bits) for each sample. Audio is usually recorded at 8-, 16-, and 20-bit depth. 8-bits per sample will generate some "hiss", comparable to hisses on a cassette tape. 16-bit samples are CD-quality level. Some new cards offer sample rates of 20-bits, allowing for very clear audio samples. The more bits used per sample, the clearer the sound but the more space consumed.
1270Samples may contain one channel (mono) or two channel (stereo) formats.
1271Lesson 31: Sound Cards
127231.4 Audio File Extensions
1273When dealing with audio files on the computer, three of the most common file formats you will come across are .WAV, .MP3 files, and ACC.
1274WAV Files
1275 
1276A Wave file is the native digital audio format used in Windows and is short for "waveform." Windows uses WAV files for general system sounds. 
1277Using a WAV format, 8-bit or 16-bit samples are commonly taken at rates of 11025 Hz, 22050 Hz and 44100 Hz. A typical WAV file (16-bit samples at 44100 Hz) uses roughly 88KB of storage per second in mono and 176KB per second in stereo.
1278The biggest drawback is that WAV files, when uncompressed, can be quite large. For example, capturing five minutes of CD quality sound in WAV format requires just over 50MB of storage. At this rate you can see how quickly a hard drive can become filled with just a small library of sound recordings. It is also the reason why file sharing of WAV files over the Internet is uncommon, with more users opting for MP3 files to store and transfer audio.
1279MP3 Files
1280 
1281MPEG stands for Motion Pictures Expert Group, which is the group that defines industry standards for digital video and audio.  MPEG-1 Layer 3, or more commonly known as "MP3" files, is the most popular format for audio files in use today. MP3's popularity became widespread for one important reason, the Internet. 
1282Using a form of “lossy” data compression technology, MP3 encoders scan a WAV file and remove portions of the sound that the human ear is not likely to hear. For example, very quiet levels of sound may be overshadowed by a much louder sound at the same time. Due to the sensitivity of the human ear, the loud sound will drown out the quiet sounds, so the quiet sounds can be safely removed without a loss in quality. 
1283This type of distilling allows transformation of large WAV files to smaller, but still CD-quality, MP3 files. For example, a 20MB WAV file converted into quality level near that of a CD only requires less than 2MB in .MP3 format. The huge reduction in size facilitates much quicker transferring of high quality audio files across the Internet. As a result, MP3 files of songs, whether illegally or legal copied, are now exchanged all over the world through the Internet.
1284AAC/MPEG-4
1285 
1286Advanced Audio Coding (AAC) is a lossy compression file format that was designed to be the replacement to MP3. ACC, also referred to as MPEG-4 or MP4, became popular when Apple began using the file format for its iPod and iPhone devices as well as their iTunes music store. 
1287An MP4 container enables the storage of video, audio, still images and subtitles in a single file and can include advanced content such as menus, user interaction and 3D graphics. The MP4 format uses compression and decompression techniques referred to as codecs to significantly decrease the size of the files by eliminating all superfluous information from each frame of the video, without losing any of the quality. 
1288The MP4 file format enables video to be more accessible. Using a high-speed broadband connections, MP4 files have streaming capabilities that allow them to be viewed in real time. Additionally, MP4 files can be downloaded, saved and viewed using an MP4 player. Low file sizes allow MP4 files to be easily shared via email. MP4s files have the .mp4 extension along with .mp4a or .mp4v extension for audio or video. MP4 technology is commonly used on websites for various purposes such as advertising and product promotion along with other purposes such as education and training.
1289Lesson 31: Sound Cards
129031.5 Audio Output
1291Computer audio has advanced far beyond the simple beeps that came out of early PCs. When properly equipped, the audio quality from a modern PC can easily rival that of a home theater.
1292There are a wide variety of computer speakers ranging in quality and price.  Two-piece speaker systems that come packaged with some computer systems are generally small, inexpensive, and have low to mediocre sound quality. Additionally, some computer displays will have basic speakers built-in to the unit. These are commonly seen in laptops. Like packaged speakers, built-in speakers also produce lower quality sound due to being restricted within a smaller space.
1293For the majority of users, these speakers will likely prove adequate for hearing standard alerts sounds and for listening to the occasional audio CD. However, for multimedia applications, home theater systems, and video games featuring 3D sound effects, a higher end speaker system can greatly enhance the listener's audio experience.
1294 
1295These more advanced speaker systems generally contain multiple small satellite speakers in combination with a subwoofer unit. 
1296•	Satellite speakers are the left and right desktop speakers commonly placed on either side of a computer monitor. Satellite speaker systems come in sets of two, three, four, and even five pieces. Subwoofers are common in satellite systems consisting of three or more speakers. 
1297•	A subwoofer is a speaker designed to exclusively reproduce sounds with lower frequencies and to enhance bass reproduction. Subwoofer speakers are always bundled with a three-to-five-piece sound system. Speakers included with subwoofers usually round out high and medium range sound frequencies to create a balanced overall sound. 
1298USB Speakers
1299 
1300USB speakers were designed to compete with sound cards. USB speakers move the digital-to-analog conversion function of the sound card to specialized sound circuitry contained within the speakers. 
1301The EMI and RFI inside a computer can cause hissing and distortion in the output that a sound card produces. By moving the sound functions out of the computer and into the speaker, EMI and RFI problems are eliminated.
1302USB speakers, however, have not received widespread popularity. USB's transfer rate is not quick enough to keep up with today's high-quality 3D sound applications and games. Also, data transferred to the speakers across the USB interface leaves little bandwidth left for devices such as scanners and printers, causing possible slowdown of the system. USB speakers are a good choice for low-end systems, but highend users should purchase a high-quality sound card.
13033D sound vs. Surround Sound
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1305Most sound cards also provide mixing capabilities, combining signals from different input sources and controlling different sound levels. 3-D sound is typically found in computer games to enhance a player’s experience. Based on a user’s location in a game, 3-D sound can be realistically produced from different directions and can reproduce the effects of sound traveling around obstacles.
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1307Common with home theater systems, surround sound also produces sound from many directions, but it doesn't change according to what the listener is doing. Rather than a two-channel recording, where sound is played on either side of the listener, surround sound supports additional channels so audio can be heard from three or more directions.  Using speakers placed in front and behind a listener, the audio appears to surround the listener providing a more immersive experience. 
1308Dolby Digital Sound
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1310Dolby digital sound is a digital audio encoding system developed by Dolby laboratories for movie and home theater systems.
1311Introduced in 1995, Dolby Digital uses Dolby's AC-3 (Audio Coding-3) coding and compression technology, providing up to six sound channels: with speaker locations at the front left, front right, front center, rear left, rear right, and a subwoofer. Dolby Digital is widely used for applications such as HDTV broadcasts, DVDs, Blu-ray discs and game consoles.
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131920-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson41/lesson41_1.html 1/2 Lesson 41: Recommendations for Workstations  41.1 Design Workstations Computers can be built to run graphics software, computer-aided design (CAD) software, or computer-aided manufacturing (CAM) software. The users of these specialized workstations are tasked to design products and parts, control the manufacturing process, create blueprints for buildings, design magazine layouts, and build websites to name just a few responsibilities. A computer that is used to run such software must support the need of the software and any connected devices. Design workstations should have a powerful processor, high-end video card, and a large amount of RAM. Selecting a Processor Select a 64-bit processor to load massive amounts of data into the system's memory. Also choose hyperthreading, which allows multithreaded software applications to perform threads in parallel on a single multi-core processor rather than processing threads one at a time. Dual-core or multiple-core CPUs are also suitable for designers’ needs. For example, dualcore is a CPU that includes two complete execution cores for each physical processor and has a grouping of two processors and their caches together with the cache controllers on a single integrated circuit. Dual-core processors are utilized for multitasking environments because there are two complete execution cores rather than one. Each core has an independent interface to the front-side bus as well as its own cache, therefore, the operating system has an abundant number of resources to handle even the most demanding tasks in parallel. Selecting a Video Card PCI Express (PCIE, PCI-E, or PCIe) operates at a high speed and is based on the PCI system. PCIe is intended to replace AGP. PCIe has a higher maximum system bus throughput and lower I/O pin count. In addition, PCIe has better performancescaling for bus devices as well as a smaller physical footprint. Lastly, PCIe contain a more comprehensive error detection and reporting mechanism along with native hot plug functionality. Selecting RAM 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson41/lesson41_1.html 2/2 Choose the maximum RAM available. Some memory caches are constructed into the design of microprocessors. These kind of internal caches are usually refer to as Level 1 (L1) caches. Today’s PCs come with external cache memory on the system board know as Level 2 (L2) caches. External caches sit in the middle of the CPU and the DRAM. Like L1 caches, L2 caches are made up of SRAM though they are larger in size (512KB to 2MB). SRAM is high-speed static RAM (SRAM) and is preferred over the slower and cheaper dynamic RAM (DRAM) used for main memory. By keeping as much of this information as possible in SRAM, the computer evades using the slower DRAM.
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132120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson41/lesson41_2.html 1/2 Lesson 41: Recommendations for Workstations  41.2 Audio/Video Editing Workstations When creating audio or video material, one can use an audio or video editing workstation. An audio editing workstation can used to record music and audio tracks, create music CDs, and design CD labels while a video editing workstation can be utilized to produce videos for businesses or the arts. An audio or video editing workstation require specialized hardware and software. Audio software is used to record audio, mix audio tracks, and publish the finalized piece. Video software is used to record, edit, and publish video clips. Consider the following hardware when you need to run audio and/or video editing software: Specialized audio card – Choose an audio card capable of handling multiple inputs for microphones and other input devices. Similarly, the audio card should have outputs to equipment that you may use to record audio from the computer. Specialized video card – Choose a video card that can handle high resolutions and multiple displays so that you can combine and edit different video feeds and special effects in real time. If multiple monitors are needed, specialized video cards that support multiple monitors are necessary when constructing an audio or video workstation. Large, fast hard drive – Modern video cameras record in high resolution at fast frame rates so even the smallest recorded video will encompass a great amount of data. Small hard drives will fill up very quickly, hence it may not be able to sustain the demands of video editing, leading to missed frames. To avoid errors or missed frames, a hard drive that is large and fast is required for recording high-end video. To increase storage speed, RAID levels such as 0 or 5, where striping is used, can be utilized. Dual monitors – When functioning with audio and video, two or more monitors can be very useful to keep track of multiple audio tracks and video clips. Remember if using multiple monitors, specialized video cards are required when constructing an audio or video workstation. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson41/lesson41_2.html 2/2
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132320-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson41/lesson41_3.html 1/1 Lesson 41: Recommendations for Workstations  41.3 Virtualization Workstations Virtualization is the simultaneous running of two or more operating systems on one computer. One type of virtualization is called Virtual Desktop Infrastructure (VDI). VDI lets users to log in to a server to get on to their own virtual computers. You may need to build a computer for a person that uses virtualization technologies. Virtual computing demands more powerful hardware configurations since each installation requires its own resources. A modern computer with modest hardware can be used to run one or two virtual environments, but a comprehensive VDI installation may need fast, expensive hardware to sustain multiple users in various environments. Some of the hardware necessary to run virtual computers include: Maximum RAM – You will need enough RAM to meet the requirements of each virtual environment and the host computer. A standard installation using simply a small number of virtual machines may need as little as 64 MB of RAM to sustain a modern operating system such as Windows XP. With multiple users, supporting many virtual computers for each user, you might need to install as much as 64 GB of RAM or more. CPU cores – Even though a single core CPU can carry out virtual computing, a CPU with extra cores can increase speed and responsiveness when hosting multiple users and virtual machines. Some VDI installations utilize computers with multiple CPUs and multiple cores.
132420-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson42/lesson42_1.html 1/1 Lesson 42: Recommendations for Desktop PCs  42.1 Gaming PC Gaming typically requires powerful hardware and large amounts of memory to ensure a smooth and enjoyable gaming experience. If building a gaming computer, consider these hardware requirements: Powerful processor – A powerful processor with multiple cores increases the responsiveness of hardware and software so that all the components work together flawlessly. High-end video card – A video card that has a fast, specialized GPU and high amounts of fast video memory is necessary to make sure that the gaming images shown on the monitor are high quality, clear, and smooth. Some gaming machines utilize multiple video cards to creates high frame rates or use multiple monitors. High-end sound card – A high-quality sound card provides a higher quality of sound for a more engaging gaming experience. A dedicated sound card also aids in overall performance improvement by decreasing the demand off of the processor. High-end cooling components – High-end video and sound components usually generate more heat than standard components. Thus more robust cooling hardware is often required to ensure computer cooling under heavy loads while playing advanced games. To keep CPUs, GPUs, and RAM cool, gamers often utilize oversized fans, heat sinks, and water cooling devices. Large amounts of fast RAM – Computer games call for large amounts of memory to function as video and sound data are continually being retrieved. Computer with more RAM, will need to read from slower storage such as hard drives or SSDs less often. Faster RAM allows the processor save all the data in sync because the data that it wishes to calculate can be retrieved when it is required. Fast storage – It is best to purchase a 7200 RPM or 10000 RPM drive. They can recover data at a much quicker rate than 5400 RPM hard drives. SSD drives are more expensive but they increase game performance drastically. Multiple monitors – The use of more than one monitor may benefits certain games. For example, flight simulators can be configured to show cockpit images through two, three, or even more monitors simultaneously. Gaming-specific hardware – If the gamer is playing games that involve talking to other players, a microphone and speakers or a headset are necessary. Some games can be played in 3D so special glasses and specific video cards may be needed to utilize the feature.
132520-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson42/lesson42_2.html 1/1 Lesson 42: Recommendations for Desktop PCs  42.2 Home Theater PC A home theater can be controlled by a specially built PC known as a Home Theater PC (HTPC). A Home Theater PC can be accessed by multiple devices at the same time. It shares files and streams video, audio, and photos not only to televisions but laptops, tablets, desktops, and other media devices. It may also be set up to record programs. Consider the following hardware when building a Home Theater PC: HTPC Compact Form Factor – When building an HTPC, use smaller motherboards so that the components can fit into a more compact form factor case, which is similar to the component typically found in a home theater. An HTPC case is consisted of large fans that move more slowly and generate less noise than those found in an average workstation. Power supplies without fans can be utilized to cut the amount of noise generated by the HTPC. Some HTPC designs have high-efficient components and does not need fans for cooling. Surround sound audio – An HTPC can utilize surround sound from the motherboard when the chipset allows it. For even better sound, use a dedicated sound to output high-quality surround sound to speakers or an additional amplifier. HDMI output – The HDMI standard permits the transmission of high-definition video, surround sound, and data to media receivers, projectors, and televisions. TV tuners and cable cards – For the HTPC to show television signals, a tuner need to be use. A TV tuner can turn analog and digital television signals into audio and video signals that can be used and stored by the computer. To receive television signals from a cable company, cables cards are needed. To access premium cable channels, a cable may be necessary. Some cable cards may get up to as many as six channels at once. Specialized hard drive – Install an A/V (audio/video) hard drive that has low noise levels and has reduced power consumption.
132620-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson42/lesson42_3.html 1/2 Lesson 42: Recommendations for Desktop PCs  42.3 Standard Thick Client/Thin Client Thick Client A thick client is not a specialized computer. Instead, a thick client is a standard computer that can be bought off the shelf. Most PCs are thick clients. A thick client is a computer that meets the recommended requirements for Windows and runs desktop applications. A thick client has hard drives and software installed on it. A thick client does not rely on a central processing server because the processing is done by the system installed on the thick client. A thick client is functional whether or not it is connected to a network. When it is not connected to a network, a thick client is usually called a “workstation”. When it is connected to a network, it is usually called a “client” since it can access servers, programs, and files on the network. Thin Client Thin clients lack hard drives, applications, and processing capabilities. Thin clients are only functional when connected to a network. They use a central processing server and access centralized applications to perform tasks. As a result, thin clients can perform difficult calculations quickly because the calculations are being performed on a server that is much more powerful than a computer such as a thick client. This also allows all end users' systems to be centrally managed and software deployed on a central server location as opposed to installed on each individual system. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson42/lesson42_3.html 2/2 Thin clients are low-powered devices. Thin clients meet the minimum requirements for running windows and run basic applications from the server. Thin clients are often used in public spaces such as airport terminals, malls, hotels, car rental agencies, schools, hospital waiting rooms, etc.
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132820-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit11/lesson42/lesson42_4.html 1/1 Lesson 42: Recommendations for Desktop PCs  42.4 Home Server PC Instead of building an HTPC, some customers ask for a Home Server PC instead. The Home Server PC can be accessed by multiple devices at the same time. Like an HTPC, a home server shares files and streams audio, video, and photos to computers, laptops, tablets, televisions, and other media devices over the network. But it can also control appliances, heating, air conditioning, lights, blinds, etc. throughout the home. Furthermore, it acts as a central server for the network allowing printing and file sharing between all computers in the home. Choose components similar to those used for the Home Theater PC. In addition, it is best practice to install a gigabit NIC to stream data to multiple devices without delays. You should also consider installing a RAID array to protect data from a hard drive failure.
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133020-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_1.html 1/3 Lesson 43: BIOS Setup  43.1 Main Menu The Basic Input/Output System (BIOS) is a computer chip on the motherboard. The BIOS contains the core firmware used to control the computer’s hardware. The BIOS provides the basic functions needed to boot a computer and to allow the operating system to access the hardware. Without the BIOS, the processor would not know how to interact or interface with the computer components, and the computer would not be able to function. It works even in the absence of an operating system. The BIOS is most critically invoked during the bootstrap process after power-up. The power-on self-test (POST) is a diagnostic program built into BIOS. At startup, BIOS executes the POST diagnostic program which checks the CPU type and speed, checks the RAM, and attempts to detect hardware including hard drives, disk drives, optical drives, floppy drives, USB ports, sound cards, video cards, NICs, etc. The BIOS gathers the current state of the hardware and displays them in the BIOS settings. The BIOS also reads information from the CMOS chip during the boot up process; the CMOS contains instructions on how hardware is loaded at start up including if some of the hardware or ports are disabled. In addition, the BIOS detects the CPU type and speed automatically. The BIOS provides basic monitoring of the following: Temperature monitoring: The BIOS displays the CPU temperature. When the CPU overheats, the computer may reboot or shut down. Fan speed: The BIOS displays the speed of the fans including the CPU fan. Chassis intrusion detection: If the computer chassis has been opened, the BIOS will show that event if this function is enabled. Voltage: The voltage settings can be monitored in the BIOS including CPU voltage, memory voltage, and motherboard voltage. Clock: The operating system gets its time from the BIOS clock at boot time. Bus speed A password can be set for the BIOS. It is set using the CMOS Setup program. When the computer boots, a password prompt will appear; if the correct password is not entered, the computer will not boot. If the password is lost, remove the CMOS battery to reset the CMOS. A BIOS is typically written to an Electrically Erasable Programmable Read-Only Memory (EEPROM) chip. The BIOS can only be updated using the manufacturer’s software, which is called “flashing the BIOS”. When you flash the BIOS, the older instructions are erased from the EEPROM chip and new instructions are written to the chip. If POST encounters a problem, the boot process stops. To troubleshoot the problem, listen for a beep code and use BIOS Central (http://www.bioscentral.com/ (http://www.bioscentral.com/)) to look up the BIOS manufacturer’s beep code; the beep code is unique for each hardware component so you can use it to determine which hardware component caused the boot process to stop. Alternatively use a POST card, which is a circuit board that fits into an ISA or PCI expansion slot in the motherboard. The POST card reports a numeric code as it checks each hardware component as the boot process progresses. If the boot process stops, the POST card stops at a number that you can look up either in the POST card manual or at BIOS Central (http://www.bioscentral.com/ (http://www.bioscentral.com/)); that will be the hardware component that caused the boot process to stop. The computer’s system provides a BIOS setup menu, which is used to configure the BIOS. To enter the BIOS setup menu, press the key or key combination specified by the startup message after turning on the computer. If the computer is used to host a virtual machine (VM), the motherboard and associated BIOS settings typically need no alteration to provide services to these virtual machines. However some hypervisors such as Microsoft Hyper-V require that the motherboard support hardware-assisted virtualization because they are installed directly on bare metal. The hypervisor 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_1.html 2/3 will need to dynamically allocate memory and CPU to the VMs as required. When the motherboard and the BIOS support this technology, make ensure that it is enabled. The BIOS Main Menu provides basic information about the system, date and time, memory, processor, and buses. BIOS Main Menu Instructions on the keys that allow you to manipulate the BIOS are located on the bottom right portion of the screen. BIOS is not GUI based; instructions are given with the Enter, Escape, Function and Arrow keys. BIOS Version The first item presented is the BIOS version. This, along with the motherboard name, is helpful for obtaining BIOS updates and information. Date and Time Be sure to correctly set the date and time. This information is passed to the operating system upon startup and is used for dating and time stamping files, email programs and other applications, cookies, and to record transactions that take place. There are online shareware utilities that synchronize the operating system clock with the accurate time. Memory Each memory slot and the amount of memory in each is listed on the BIOS Main screen. In the example above, there are four slots, and two of them contain 512MB each. This information is useful for troubleshooting memory that is not recognized by the system. Processor and Buses The processor's speed, cache, and type are listed along with the speeds of the system bus and data bus. If any of the information on the processor is incorrect, the BIOS may need to be updated. An outdated BIOS that doesn't recognize a processor can result in processor features not being enabled and the processor may run at slower speeds than it is capable of. One other feature that effects the processor is AW Single Processor Mode. This deals with dual-core processors. If enabled, only one of the processors on the dual-core will be used, which will reduce the overall processing power. Be sure to disable this feature on motherboards that contain a dual-core processor. Flashing the BIOS 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_1.html 3/3  Editor's Note BIOS software is, in some regards, like other computer software. There are newer versions available that contain updates, enhanced features, new features, and bug fixes. To erase the BIOS and reprogram it, a special program called a flash utility is used. On systems with a non-flashable BIOS, the entire CMOS chip must be replaced to perform an upgrade. BIOS upgrades are often found on the manufacturer's Web site. To get the right BIOS, it is essential to know the model number of the motherboard. Important! Before flashing the BIOS, make sure to write down the BIOS settings. The settings must be reentered after flashing. Warning! Do not turn off the PC while flashing the BIOS. The motherboard will be rendered inoperable.
133120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 1/7 Lesson 43: BIOS Setup  43.2 Advanced Menu The BIOS Advanced Menu provides configuration options for peripherals, drives, video, the chipset, and USB along with hardware monitoring options. As the screen warns, do not change these settings unless you are certain that you know what you are doing. Otherwise, your system may malfunction. BIOS Advanced Menu Boot Configuration The Boot Configuration has options that control settings that occur during bootup. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 2/7 Numblock - Numblock determines whether the number lock will be enabled or disabled by default after the system boots up. CPU Fan Control and System Fan Control - The CPU and System Fan Control should be enabled so that the CPU and system fans can be manipulated as the system and the processor's temperature increases and decreases. Max CPUID Value Limit - The Max CPUID Value Limit is used for older operating systems that are used with newer processors. When the system boots up, CPUID instructions identify the processor's capabilities. For example, if an operating system such as Windows ME or 9x is used with a Pentium 4, which was created after those operating systems were designed, the system will not be able to use the extra functions of the Pentium 4 such as Hyper-Threading. In this example, the Max CPUID Value Limit should be enabled so that the processor can be used with the older operating system, however the processor's advanced functions such as HyperThreading will not work. In most cases, the Max CPUID Value Limit should be disabled. Display Setup Prompt - The last option in the Boot Configuration menu is the Display Setup Prompt, which sets whether the prompt "BIOS Settings " is displayed while the system is booting. This setting should be set to "On." Peripheral Configuration 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 3/7 The Peripheral Configuration menu simply allows the enabling or disabling of peripherals such as the serial port, parallel port, integrated audio ports, onboard LAN port, and onboard 1394, which are FireWire ports. Drive Configuration The Drive Configuration menu configures drive settings for IDE and SATA controllers. Use Automatic Mode - The Use Automatic Mode setting allows manual or automatic configuration of IDE controllers. Set to enable to allow automatic configuration and disable to allow manual configuration. ATA/IDE Mode - ATA/IDE Mode set on legacy mode will force the IDE controller to use dedicated IRQs that cannot be shared and should be used if the operating system is Windows Dos, ME, 98, or NT. This setting should be set to 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 4/7 native, which would allow the IDE controllers IRQs to be shared with other devices and would enable all SATA and PATA resources. Configure SATA As - The Configure SATA As setting can be either IDE, AHCI (sometimes called SATA), or RAID. IDE mode uses a different driver for the SATA controller and does not allow RAID. This setting is not recommended. AHCI mode enables SATA to operate normally, but does not allow a RAID configuration. RAID mode is the most flexible since it allows normal SATA operation and RAID configuration. S.M.A.R.T. - S.M.A.R.T. is a technology that enables monitoring of hard drives so that potential failures to the hard drive can be reported before they happen, thus allowing data to be backed up prior to a fatal failure of the drive. S.M.A.R.T., used in conjunction with a hard drive monitoring utilities such as the free DiskCheckup by PassMark, reports on the time to spin up, attempts to reread or rewrite due to defective sectors, and head seek failures along with information such as hard drive temperature and basic hard drive manufacturing information. This can be crucial information that gives a warning to save data before a hard drive crashes. A home hard drive that crashes is an annoyance. A company hard drive that crashes may lose that company thousands of dollars or more worth of data work and essential information. S.M.A.R.T. technology can be very useful. SATA Port X and Primary Master / Slave - This setting displays the devices that are connected to the SATA and IDE controllers. Event Log Configuration All POST errors are logged. The Event Log Configuration menu allows users to look at these logs and configure the event log. View Event Log - This displays all POST errors. Clear Event Log - This option deletes all errors that were previously logged or retains event log errors when the system restarts. Event Logging - Enables or disables event logging. Mark Events As Read - This option sets all unread events as read. Video Configuration 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 5/7 DVMT Mode - DVMT stands for Dynamic Video Memory Technology which sets the maximum amount of needed memory to be used for graphics, but not more than is needed so that system performance is not needlessly effected. IGD DVMT Memory - This option sets how much system RAM is reserved for graphics. "Max" is the default and recommended setting. IGD Aperture Size - Aperture memory is used when the video card's memory runs out. Set this to a lower setting if a video card with lots of memory is used or if graphical demands on the system will be low. If the system is used for games that require large amounts of texture memory, use the largest setting. Primary Video Adapter - This option sets up which video adapter to use during the boot process. Auto allows the system to sense the monitor connection. PCI and PCIE allow a video card slot to be selected while Integrated Graphics (IGD) uses the integrated monitor port. Hardware Monitoring This screen allows monitoring of critical voltages, temperatures, and fan speeds. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 6/7 Chipset Configuration Memory Configuration - Memory configuration can be set to automatic, manual aggressive, or manual user defined. Automatic sets all memory timings to be set according to the specifications of the detected memory. Manual aggressive sets all memory timings to their most aggressive settings. Manual user defined allows manual setting of all SDRAM settings. PCI Express Configuration - PCI Express settings such as the negotiated width of the installed PCIe card are displayed. Another option is Compliance Test Pattern, which must be enabled for this PCIe troubleshooting option to work. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_2.html 7/7 PCI Latency Timer - The length of time that a device on a PC bus can hold the bus when another device has requested the bus. If this setting is high, devices may have to wait longer before they get a chance to send data on the PCI bus. If this setting is low, devices will switch control of the bus more often. This prevents large data bursts, which results in larger overheads and reduced performance of attached devices. System stability, however, may improve because devices do not have to wait for the bus. Usually this setting is in the middle which provides balanced system stability and device performance. HPET - HPET is an improved timer that replaced the legacy 8254 Programmable Interval Timer and Real Time Clock which generate interrupts for hardware requests. This option should be set to enable. USB Configuration USB Ports - This option enables or disables the USB ports. USB Legacy - This option allows the BIOS to interact with a USB keyboard and mouse.
133220-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_3.html 1/2  Editor's Note Lesson 43: BIOS Setup  43.3 Security Menu The BIOS Security Menu deals with system security issues such as passwords, chassis intrusion, and virus protection. Supervisor Password The Supervisor Password screen has one feature: setting up a master password for locking user(s) out of the system BIOS setup screen. A supervisor password is used in large institutions where BIOS settings are kept standardized by a computer support staff. Once set, BIOS setups are locked with a master password only known to the network administrator or a designee. Password security prevents users from accidentally or experimentally changing the settings and causing system problems requiring support staff intervention. You are not likely to find Supervisor password security outside of large institutions like corporations or large school districts. Password Security, when enabled, prompts you to enter a password, then enter it again for confirmation. Instructions for Supervisor Password are found in your motherboard manual. If you accidentally engage Supervisor, bypass it easily by pressing the Enter key without entering a password at the prompt. Following the prompt, the message, "Password Disabled!!!" will appear. Pressing any key will return you to the main setup screen. User Password The User Password option allows you to install a password that will keep the system from booting unless the proper password is entered. This option also prevents access to the BIOS. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_3.html 2/2 The BIOS password is a nice, basic security feature, but what if the password is forgotten? The password can be cleared by removing the motherboard’s CMOS battery or by clearing the CMOS with a jumper on the motherboard. The BIOS will not be cleared because it is stored in ROM. The CMOS is actually a small section of the BIOS chip that is cleared with the loss of electricity. Expansion Card Text This option enables or disables add-in BIOS cards (i.e. a SCSI/RAID card) to display text on the screen when initializing during system boot. Chassis Intrusion Chassis Intrusion can be either enabled or disabled. If Chassis Intrusion is enabled and a system's case is opened, this event is logged in the event log and the event is posted on the screen during the next POST. F4 must be pressed in order for POST and booting to continue. This will occur during every POST until Clear Chassis Intrusion Status is selected in the BIOS. Although most cases can be locked, this is a useful tool that can at least report if a case has been accessed by inappropriate persons. XD Technology This setting enables Intel's Execute Disable Bit technology, which protects data pages against attacks by malicious worms which attempt to execute large amounts of code that can overwhelm the processor. This option should be set to enable. Test Your Knowledge You are attempting to enter a system's BIOS, but realize you've forgotten the password. What can you do? A. Use the generic password of BIOS1234. B. Contact the motherboard manufacturer for the override password. C. The password can be found in the operating system's registry. D. Clear the BIOS by removing the CMOS battery or by using jumpers. E. Buy a new computer or motherboard. There is no way to access the BIOS unless the password is entered.
133320-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_4.html 1/1 Lesson 43: BIOS Setup  43.4 Power Menu The BIOS Power Menu allows changing the system’s optional device power management features. When device power management features are enabled, you can control if and when some devices in the system will go into sleep or into suspend mode. After Power Failure This setting sets the mode of operation if the AC power loss occurs. Stay Off means the power will stay off until the power button is pushed. Last State means that if the system was on it will turn back on once AC power is restored, however if the system was off it will remain off. Power On means that the system will turn on once AC power is restored. Wake On LAN From S5 This setting enables the system to turn on for a Wakeup On LAN event, or it disables this function. Enhanced Intel Speedstep Technology Enhanced Intel Speedstep Technology (EIST) allows a system to control processor voltage and core frequency in order to decrease power consumption. Wake System From S5 This setting enables the system to turn on for a Wakeup event, or it disables this function.
133420-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_5.html 1/2 Lesson 43: BIOS Setup  43.5 Boot Menu The BIOS Boot Menu section allows boot features and the boot sequence to be set. Boot Device Priority This option specifies the boot sequence according to device types. Hard Drive, Floppy Drive System will first search for hard disk drive, then floppy disk drive. Floppy Drive, Hard Drive, USB System will first search for floppy disk drive, then hard disk drive, then USB drive. CDROM, Hard Drive, USB System will first search for CDROM drive, then hard disk drive, and then USB drive. Hard Drive, CDROM, USB System will first search for hard disk drive, then CDROM drive, and then USB drive. Hard Drive, CD/DVD-ROM, and Removable Drive Order This option lists the name of the particular device to be used for the Boot Device Priority menu. Boot to Optical Devices, Removable Devices, and Network Boot Sequence 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_5.html 2/2  Editor's Note This option enables or disables booting through optical devices, removable devices, or through the network. USB Boot This option enables or disables booting through USB boot devices. Zip Emulation Type This option enables booting with a USB zip drive by setting it to emulate a hard drive. Boot USB Devices First This option enables or disables USB devices to boot first. USB Mass Storage Emulation Type This option sets the emulation type for USB drives. Auto checks and uses the USB drive's settings. All Removable sets the USB drive to emulate removable drives. All Fixed Disc sets the USB drive to emulate fixed discs. Finally, the Size setting sets the USB drive to emulate based on the media's size. If a computer will not boot up, make sure that the proper boot order is set in the BIOS. For example, if you want the PC to boot off of the primary master hard-drive first and the CD-ROM second, set the boot order to C, CD-ROM.
133520-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_6.html 1/2 Lesson 43: BIOS Setup  43.6 Exiting and Saving The BIOS Exit menu presents various options to exit with or without saving changes to the BIOS settings and also allows the loading of default and optimal BIOS settings. Exit Saving Changes Save and Exit Setup is the only setting for exiting the BIOS setup program and saving your changes to the CMOS chip. Although there are shortcuts, it is always best to use the exit feature to keep from accidentally losing all your setup modification entries. Exit Discarding Changes Exit Without Saving discards all modified settings you have made to the BIOS and exits the BIOS. Load Optimal Defaults This option provides a choice of whether to reset the BIOS setup screens to optimal default settings. Load Custom Defaults The BIOS Load Custom Defaults option provides a choice of whether to reset the BIOS setup screens to custom default settings. The Load Custom Defaults section returns the system to a stable state, helpful when it comes time to troubleshoot the system. Always be sure to document the BIOS settings before making any changes. Save Custom Defaults This option sets the current values as the custom default. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_6.html 2/2 Discard Changes All changes to BIOS settings are discarded and returned to their previous states without exiting the BIOS setup.
133620-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 1/9 Lesson 43: BIOS Setup  43.7 Unified Extensible Firmware Interface The Unified Extensible Firmware Interface (UEFI) is the next generation of the BIOS and provides advanced control of the boot-up process. The UEFI runs before the primary OS starts up. UEFI accesses the PC hardware such as the mouse and network connections. In addition, UEFI leverages modern video cards and monitors and can access the Internet. UEFI provides an intuitive user interface and enables a simpler dual-booting process. UEFI also offers a greater visual experience and is able to be controlled by a mouse. UEFI exists on a disk or in nonvolatile memory on the motherboard along with being able to exist on a network share. Windows 8 utilizes the UEFI for system repair store and image recovery and UEFI secure boot uses Public Key Infrastructure (PKI) digital certificates to validate programs, peripherals, and OS loaders prior to running. UEFI secure boot has two options. PCs allow the user to turn off UEFI secure boot entirely or a user can use the custom secure boot mode by typing in a signature for the desired OS loader. With Windows 8, all PCs have the Windows 8- certified logo to with the secure boot feature enabled. Depending on the manufacturer, the UEFI interface may appear as simple as the outgoing BIOS, or it might make use of images and icons, while also providing mouse and screenshot support. In addition to overcoming the limitations of the traditional BIOS, UEFI allows for manufacturers and vendors to re-use code for modularity and to allow room for customizations, innovation, and quicker time-to-market for their products. MSI, ASUS, and Gigabyte motherboard manufacturers UEFI 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 2/9 ASUS UEFI Interface - Notice the Cursor 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 3/9 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 4/9 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 5/9 Accessing BIOS Information In order to determine if a PC uses UEFI or BIOS: 1. Open File Explorer. 2. Go to the folder: C:\Windows\Panther. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 6/9 3. Within the Panther folder, there is a text file titled setupact.log, which will automatically open in Notepad. 4. When the setupact.log is open, click Ctrl+F. 5. The Find box will pop up. 6. Search for Detected Boot Environment. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 7/9 7. BIOS or UEFI will appear: Callback_BootEnvironmentDetect: Detected boot environment: BIOS Or Callback_BootEnvironmentDetect: Detected boot environment: UEFI To determine if a PC running Windows 8 or 8.1 uses UEFI or BIOS: 1. Access the Run command utility. 2. Enter MSInfo32, and press Enter. 3. System Information will open. 4. Listed in the summary list, among the BIOS entries will be BIOS Mode which will display either Legacy or UEFI. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 8/9 Booting into UEFI Firmware BIOS from Windows 8 - 8.1 Follow the simulation below to enter the UEFI Firmware settings in Windows 8: Boot to UEFI Firmware Settings in Windows 8 In order to access UEFI Firmware settings on Windows 8: 1. Access PC settings from the Charms panel → Settings → Change PC settings. 2. From the PC settings screen, click on General. 3. Click the Restart Now button under the Advanced startup section. 4. Choose Troubleshoot from the Options screen following reboot. 5. On the Troubleshoot screen, click Advanced options. 6. On the Advanced options screen, click the UEFI Firmware settings button. 7. To reboot into the UEFI, click the Restart button. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson43/lesson43_7.html 9/9 8. The PC will restart and automatically boot to the UEFI firmware settings screen associated with the model of the Motherboard.. In order to access UEFI Firmware settings on Windows 8.1: Follow the simulation below to enter the UEFI Firmware settings in Windows 8.1: Boot to UEFI Firmware Settings in Windows 8.1 1. Access PC settings from the Start screen → All Apps → PC settings. 2. From the PC settings screen, click on Update and recovery. 3. On the Update and recovery screen, click Recovery. 4. Click the Restart Now button under the Advanced startup section. 5. Choose Troubleshoot from the Options screen following reboot. 6. On the Troubleshoot screen, click Advanced options. 7. On the Advanced options screen, click the UEFI Firmware settings button. 8. To reboot into the UEFI, click the Restart button. 9. The PC will restart and automatically boot to the UEFI firmware settings screen associated with the model of the Motherboard.
133720-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_1.html 1/1 Lesson 44: Introduction to Operating Systems  44.1 What is an Operating System? The operating system is the software that controls hardware and provides higher level routines for application programs. For example, most operating systems read and write data to and from files. The operating system translates requests for operations on files, while converting files into primitive operations the disk controller can carry out (for example, read a block, write a block). Operating systems perform the following basic tasks: recognizing input from the keyboard or mouse sending output to the monitor or printer keeping track of files on the hard drives controlling peripherals such as printers, modems, etc.
133820-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_2.html 1/2  Editor's Note Lesson 44: Introduction to Operating Systems  44.2 OS Components The operating system is composed of modular components, each of which has its own distinct function. The major design components of any operating system are the following: User interface Kernel File management system What is the User interface? The User interface is the operating system shell used to issue commands to a computer. There are two main types of user interfaces: command prompt and Graphical User Interface (GUI). A command prompt interface requires a user to type commands when given a prompt. A Graphical User Interface (GUI), replaces command prompts with graphics, a cursor, and the ability to "point and click" with a mouse. A user interface acts as a mediator between complex computer operations and people. A user interface presents data in a logical graphical manner, and provides users the ability to issue commands and exchange data with a computer. What is the kernel? The kernel is the core of the operating system. A kernel takes responsibility for memory management, program objectives (tasks), program execution (processes), and disk files. Operating systems can either manage one program at a time, called single tasking, or several concurrently, called, multi-tasking. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_2.html 2/2 When a kernel is multi-tasking it appears as if it is working on separate tasks simultaneously. However this is not the case. Actually, in multitasking, the system is spending a fraction of a nanosecond on each task, switching back and forth between them. What is the File Management System? A file management system is the operating system portion that organizes and manages files. A file is a collection of data that has a single logical name (filename); nearly all computer information is stored in file form. Files types vary: video, programs, and text, to name a few. Most operating systems use a hierarchical file system, meaning files and directories are organized in a tree-like structure. The top, or highest directory is called the root directory.
133920-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_3.html 1/4 Lesson 44: Introduction to Operating Systems  44.3 Modern Operating Systems A variety of non-proprietary operating systems are currently available. Choosing an appropriate operating system depends on the purpose type of the computer [being used] and performance level desired by user. When choosing an operating system, it is important to consider its features and compatibility. There are many different operating systems to choose from, each offering its own distinct advantages and disadvantages. This section takes a closer look at some of the most popular operating systems being used today, while the next section discusses some of the legacy operating systems that have since been replaced. Windows 8 The Windows 8 operating system was released for general availability on October 2012. New features are comprised of a touch-optimized Windows shell, the Start screen, a new platform for creating apps stressing touchscreen input, assimilation with online services, and a Windows Store. Windows 8 supports USB 3.0, Advanced Format hard drives, near field communications, and cloud computing. In addition, Windows 8 includes several security features including built-in antivirus software and integration with SmartScreen phishing filtering. Support for UEFI Secure Boot is also included, which stops malware from contaminating the boot process. Additional functionality in Windows 8 includes: A quicker startup through UEFI integration A "Hybrid Boot" mode that hibernates the Windows kernel on shutdown (which speeds up the subsequent boot) Support for near field communication The ability for Enterprise users to create live USB versions of Windows Support for the hard disk 4Kn (4K native mode) Advanced Format support A new lock screen with a clock and notifications Native support for USB 3.0 devices permitting faster data transfers and enhanced power management with compatible devices 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_3.html 2/4 In Windows 8, the Windows Explorer consists of a ribbon in place of the command bar. The file operation dialog boxes offer more thorough statistics along with the ability to suspend file transfers and manage conflicts when copying files. The new File History permits incremental revisions of files to be backed up to and restored from a secondary storage device. Storage Spaces permits the combination of various sizes of hard disks into virtual drives. The Task Manager consisted of a processes tab with the possibility of displaying fewer or more details of running applications and background processes along with a heat map utilizing various colors to show the level of resource usage, network and disk counters, assembled together base on the process type, and friendly names for processes. As far as safety and security features, Windows 8 contains new authentication methods designed for touchscreens including PINs and picture passwords along with antivirus abilities with Windows Defender. Both SmartScreen filtering and Family Safety provide activity reports and safety controls. In Windows 8, system recovery is available through the “Refresh” and "Reset” functions along with system recovery from the USB drive. The UEFI specification known as secure boot is supported by Windows and utilizes a public-key infrastructure to authenticate the integrity of the operating system, which stops unauthorized programs such as bootkits from contaminating the device's boot process. Windows 8 offers access to on-line services in order to synchronize applications and settings among devices and comes with a client app for the Microsoft's SkyDrive cloud storage service, which also permits apps to save files straight to SkyDrive. Windows 8 ships with Internet Explorer 10 and incorporates improved provision for mobile broadband in addition to an airplane mode setting to globally inactivate all wireless connectivity as well. Windows 7 In response to a large number of criticisms about Vista, Windows 7 offers many of the same features in a less cumbersome way--easier installation, fewer windows to juggle, fewer compatibility issues, and a simpler interface to navigate. Windows 7 requires less memory than its predecessor and has reworked its GUI scheduling to create fewer conflicts and improve its speed and stability. The most obvious visible different appearing feature is the Windows 7 taskbar; it replaces small icons with text labels with larger unlabeled icons to reduce clutter (a feature that you can customize as desired). Windows Vista Microsoft's Windows Vista offered a plethora of new features over XP, with a brand new look. Vista introduced a new visual style called Windows Aero (similar to Mac OS X's Aqua). Vista was made more intuitive and helpful with its new GUI. One example of this is the ability to play, share, and burn MP3s in the music folder. Multimedia functions such as DVD Maker, Photo Gallery, speech recognition, and all of the functions included in XP Media Edition were been included. There are simply too many improvements from XP in Vista to adequately explore them all. Windows Vista made a completely new operating system, not just a slightly improved version of XP. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_3.html 3/4 MAC OS X The Mac OS has gone through many revisions. The most current is Mac OS X, an open source operating system that is very stable and more powerful than previous versions. OS X competes with Microsoft's operating systems by including powerful new search tools, improved shortcuts, an improved look with Aqua, and software development tools. Mac OS X now provides support for easier networking between Macs and PCs. Taking the mixing of Mac and PC even further, a software package called Parallels Desktop allows both operating systems to run on an Intel Mac at the same time, switching between the two as needed and running applications from both simultaneously. Apple Macs continue to grow in popularity as newer Mac OS versions continually improve. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_3.html 4/4 UNIX UNIX is the oldest, most stable, and most robust of the operating systems run on non-proprietary computer servers and workstations systems. Originally developed by Bell Labs with AT&T in the 1970’s, UNIX has spawned several variants and several different sets of standards, and continues to be improved with each new version. UNIX has a reputation for being an enormously powerful, multi-tasking system that supports several robust file systems. Unfortunately, UNIX suffers from a difficult, non-standardized graphical user interface. Numerous UNIX variants are not crosscompatible. Historically, its difficult interface and its lack of cross-compatibility have limited UNIX's acceptance amongst the general computer-user population. Its stability and the development of a graphical user interface have helped fuel UNIX's resurgence. Major UNIX OS variants are produced by the Santa Cruz Operation (SCO), Sun Microsystems (Solaris), Hewlett Packard (HP-UX) Digital Equipment Corporation (DEC), and IBM (AIX). Linux Linux evolved from Unix, and developed in 1991 by a Finnish Graduate student named Linus Torvald. The Linux operating system was originally developed as a public-access variant of UNIX, and initially distributed for free, via the Internet. Due to its nominal cost and free distribution, it's flexibility, and the fact that most hackers target Microsoft systems, the Linux operating system's market share continues to grow. Because of Linux's enormous user base, Linux has become a well-supported operating system. Linux retains some of the same graphical user interface problems as UNIX, however, unlike UNIX, Linux can support numerous file systems. The market for Linux is growing rapidly as users find it to be stable, robust, and flexible.
134020-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 1/6 Lesson 44: Introduction to Operating Systems  44.4 Legacy Operating Systems With each new operating system release, there is one that it typically will replace. These may still be used for their original purpose, though they may not be supported in the near future. Newer hardware may not run on older systems as well as newer programs, or program upgrades. Security issues are always addressed with each new operating system upgrade as it must stay one step ahead of attackers. Because of this, it is not recommended to use a legacy operating system unless proper measures are taken to secure the system as well as any network it connects to. Windows XP Windows XP is the golden child of Windows operating systems. XP is a huge improvement from Windows 9x and 2000. Windows XP is an extremely stable 32 bit operating system that has faster startup and wakeup times, includes system restore, has improved multitasking abilities, integrated wireless support, better security by far when compared to 9x, and took the multimedia improvements started in 98 to a whole new level. Windows XP Professional edition adds multiple processor support, remote assistance, Automated System Recovery (ASR), dynamic disk support, web server functions, and even more security options. Microsoft also offers XP Pro in a 64-bit edition. 1981 1984 1987 1992 1996 1998 2000 2001 198 MSDeveloped by Micro licensed by IBM, becam standard for all PC "clo The MS-DOS kernel is c command.com. Th system, File Allocation Table (FAT), is still used to Early Operating Systems 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 2/6 Windows XP is still used in a large number of PC systems. Although Vista made many improvements, until its bugs are worked out and it has proven itself to be better than XP, many users will continue to use XP. Windows 2000 Windows 2000, in both professional (desktop) and server editions, maintains NT 4.0's network security standards. Windows 2000 is based on NT technology; however, there are many differences between the two operating systems. As a testament to this, Windows 2000 features over 50% new and reworked code. A few of 2000's enhanced features include: an automatically personalized Start menu and a Network Connections Wizard. The Network Connection Wizard is a step-by-step series of dialog boxes that guide users through the process of arranging computer-to-computer hook-up by way of infrared, serial, or parallel port connections. These features were designed to streamline administration of 2000 networks. Windows 98 There were two separate releases of Windows 98, a first edition and second edition. Nonetheless, both editions of Windows 98 operate like their Windows 95 predecessor. Windows 98 offered many enhanced features, including: improved Internet integration, enhanced support for multimedia and multiple monitors, and a helpful Maintenance Wizard. Windows 98's second edition improved network security features and offered a specification utility for removable disks and other storage hardware. Internet connection sharing was also enhanced, providing every networked Windows 98 client with single-host Internet access. Windows 95 and 98 are commonly referred to as 9x, and are the only operating system of their type, besides Windows ME. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 3/6 Windows ME was similar to 95 and 98, however ME added features such as Universal Plug and Play, Automatic Updates, System Restore, and more multimedia functionality. Windows ME, however, was a complete failure and was replaced very quickly by Windows XP. Windows NT 4.0 Upon its release in 1996, Windows NT 4.0 (Windows New Technology) was considered an extremely robust and powerful multi-tasking operating system with a GUI interface nearly identical to Windows 95's. Despite these similarities, there are many differences. For example, Windows NT 4.0 has a completely different kernel and file system than other Microsoft operating systems. Since its initial introduction in 1993, Windows NT has been through multiple revisions. Windows NT was developed by designers who had gained experience designing larger, more complex mainframe/minicomputer operating systems. In fact, NT was intended to create a more secure environment for heavy-duty applications. Windows NT's capabilities and robust nature reflect these design origins, while each new version continues to feature enhanced capabilities. Most importantly, the Windows NT kernel (ntoskrnl.exe) is extremely flexible and creates operating environments that support MS-DOS, Windows 3.1, and even OS/2 applications in addition to applications native to the NT environment. NT's file system, called NTFS, is extremely secure and fault tolerant. Windows 95 Windows 95 was developed and released by the Microsoft Corporation in 1995. Windows 95 is the successor to the MS-DOS operating system that incorporated the Windows 3.1 graphical shell. Although Windows 95's capabilities far exceed its predecessor's, Windows 95 still employs many variants of the original MS-DOS kernel and DOS file system (FAT). 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 4/6 Windows 95 was one of the most widely distributed operating systems on the market. Windows 95 supports MS-DOS, Windows 3.1, as well as native Windows 95 applications. Another reason for Windows 95's popularity was is its ability to multitask. Microsoft continued to release updated and refined versions of Windows 95 such as Windows 98 and Windows 2000. Generically, these updates are referred to as Windows 9x. Updated versions provided content improvements, advanced multimedia options, networking capabilities, Plug and Play compatibility, and Internet support. MS-DOS MS-DOS, developed by Microsoft in the early 1980s, is one of the most commonly used operating systems in the world. Initially licensed by IBM for its newly developed PC, MS-DOS was adopted as the standard by all PC "clone" manufacturers in the mid-1980s. In 1992 an MS-DOS graphical shell called Windows 3.1 was released, forever changing the face of computing. Microsoft had multiple versions of Windows 3.x, an application that worked on top of MS-DOS. Windows 3.x not only added GUI, but also added more drivers, an improved memory management system, the ability to use some multimedia applications, some networking functions, and file sharing. By itself, DOS is only a single-tasking operating system, however, it includes limited multi-tasking when used in conjunction with the Windows 3.1 GUI shell. The MS-DOS kernel is called command.com. Variants of DOS's file system, known as the File Allocation Table (FAT), are still core components found in newer Microsoft Windows operating systems. Mac OS Another common operating system is the Mac OS, developed for and used by Macintosh (Mac) computers. Created by Apple Computers and released in 1984, Mac OS featured the first true graphical user interface-based operating system. The Mac OS model was originally created in the 1970s by the Xerox Corporation. Fortunately for Apple, Xerox executives were shortsighted and didn't believe that a GUI-based operating system would be a big seller, choosing instead to give their new technology to Apple. The Mac OS uses the Hierarchical File System (HFS) in much the same way that Microsoft operating systems use the File Allocation Table (FAT) and NT File System (NTFS). 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 5/6 The Macintosh operating system was an extremely popular alternative to the Microsoft-based DOS and Windows operating systems through the early 1990s. Lack of compatibility with PC-based software had a negative effect on Apple sales through much of the 90's. However, in recent years updated Apple hardware and a newly revamped Mac OS has led to a resurgence in Macintosh's popularity. OS/2 OS/2, or Operating System 2, was originally developed in the late 1980s as a joint project by the IBM Corporation and Microsoft. However, due to disagreements over the direction of OS/2 development, the co-developers split in the early 1990s, leaving IBM to continue development of the operating system. OS/2's popularity amongst home and small business computer users has slipped since the early 90s, but OS/2 continues to be popular in large institutions where its integration with IBM mainframe technologies is prized. OS/2 has an excellent file system, HPFS that supports multi-tasking and features a user-friendly GUI. Unfortunately, very few applications are designed for the OS/2 interface. Although IBM continues to develop and support it, OS/2 has reached a dead-end in the PC desktop world. Unix 1970's Multi Text and Graphical Varies AT&T/Bell Labs MS-DOS early 1980's Single Text only FAT Microsoft Mac OS 1984 Multi Graphical HFS Apple OS/2 late 1980's Multi Graphical HPFS IBM Linux 1991 Multi Text and Graphical Varies Linus Torvald Windows 3.x 1992 Multi Graphical FAT Microsoft Windows NT 1993 Multi Graphical NTFS/FAT Microsoft OS Year Tasking User interface File system Original Manufacturer 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson44/lesson44_4.html 6/6 Windows 95/98 95/98 Multi Graphical FAT/FAT32 Microsoft Windows 2000 2000 Multi Graphical NTFS/FAT/ FAT32 Microsoft Windows XP 2001 Multi Graphical NTFS/FAT/ FAT32 Microsoft Mac OS X 2005 Multi Graphical HFS+ Apple Windows Vista 2007 Multi Graphical NTFS/FAT/ FAT32 Microsoft Windows 7 2009 Multi Graphical NTFS/FAT/ FAT32 Microsoft
134120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_1.html 1/3 Lesson 45: Windows Vista, 7, and 8  45.1 Windows Vista Released in 2007, Microsoft's Windows Vista 32 and 64-bit operating system was intended to replace Windows XP as next generation of Microsoft operating systems. Windows Vista offered a new look with lots of new features. Vista took longer than expected to be developed but when it hit the market; reviews declared it as a major success and worth the wait. Vista was more secure, more user friendly, and its new features made it much more useful than any of Window's previous operating systems. Windows Vista Features a more Refined Start Menu Windows Vista Versions Windows Vista is available in a few different versions for the desktop. The versions available currently include Home Basic, Home Premium, Ultimate, and Business. Windows Vista Home Basic Edition Windows Vista Home Basic Edition is used for budget users who will only need to use the Internet, send emails, view photos, listen to music, and perform other basic functions. Windows Vista Home Premium Edition Windows Vista Home Premium Edition is what the majority of home systems will use. While it does not contain the exceptional security and extra features of Ultimate and Business, Vista Home Premium contains all of the features that makes Vista more than just an upgrade from Windows XP. With more multimedia functions and programs than XP, better security, improved search functions, and a completely new look with Windows Aero, Vista Home Premium is the operating system edition of choice for home users. Windows Vista Business 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_1.html 2/3 Windows Vista Business is designed for small businesses. With an improved interface, better security (including hard disk encryption), an improved file system for better organization and improved search functions, and improved user privilege settings, Windows Vista is designed to increase productivity and provide even more resources for businesses than XP. Windows Vista Ultimate Windows Vista Ultimate is a mix between Premium and Business. Combining the security, efficiency, and productivity aspects of Business with the improved looks and multimedia functions of Home Premium, Ultimate is for businesses or home users that want all of the new features that Microsoft has been working for years to create. Windows Vista Environment Windows Vista includes numerous enhancements that make it an exceptional operating system. Some features listed below are only available on higher versions of Windows Vista. Windows Vista features more visually dynamic transitions. Security Windows Vista has new User Account Controls that increase the security of almost all aspects of the operating system by requesting an administrative password for all privileged functions. Hard drives are now encrypted using Windows BitLocker Drive Encryption. Windows Defender provides security from malware and spyware, while Windows Firewall has been improved to filter both incoming and outgoing traffic. Internet Explorer version 7 also adds a phishing filter, more parental controls, and other security features such as disabling ActiveX controls by default. Visual Style Windows Vista has a completely new visual style with Windows Aero. With Windows Flip 3D, Glass, thumbnails and animations, Vista showcases exceptional 3D graphics, translucency effects, and other new GUI features that give Vista a completely new look and feel. Multimedia Windows Vista adds an improved Windows Media Player with version 11, Windows Photo Gallery, DVD Maker, all media functions from Windows XP Media Center edition, and speech recognition to improve the multimedia aspects of the operating system. Miscellaneous 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_1.html 3/3  Editor's Note Windows Vista introduces so many new little features that it is impossible to cover them all in one lesson. There are plenty of blogs, reviews, and opinions available online on Vista and all of Vista's new features. Perform a search to obtain more information on the myriad of new features available with Windows Vista. Minimum Requirements of the Windows Vista Operating System For a computer to accommodate and successfully support Windows Vista, it must first meet the following hardware requirements: A 1GHz (or higher) 32 or 64-bit computer processor 512MB or 1GB of memory (or higher) depending upon the version of Vista used At least 20GB or 40GB of free hard-disk space is required depending upon the version. Requirements, however, will vary depending on a system's configuration and selected options. Support for DirectX 9 graphics and a minimum of 32MB or 128MB of graphics memory All versions except for Home Basic also require a WDDM driver, Pixel Shader 2.0 in hardware, and 32 bits per pixel A DVD drive Audio Output Internet Access Home Basic has the lowest requirements of all of the versions. All higher requirements are for the Home Premium, Business, and Ultimate versions.
134220-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_2.html 1/2 Lesson 45: Windows Vista, 7, and 8  45.2 Windows 7 Released in 2009, Microsoft's Windows 7 operating system is still frequently used. Available as a 32 or 64-bit operating system, Windows 7 added lots of new features and added improvements on features previously existing in Vista. A new version of Windows Media Center with its own Gadget, support for virtual hard disks, improved performance for multi-core processors, added support for multiple graphics cards, and support for RAW image format and many more. Windows 7 Start Menu Windows 7 Editions There are three different editions of Windows 7 available to consumers - Home Premium, Professional and Ultimate. There are other versions available pre-installed on netbooks etc. with limited enhancements, or volume licensed for business organizations and government. Windows 7 Home Premium Edition Windows 7 Home Premium Edition is what the majority of home systems will use. While it does not contain the exceptional security and extra features of Ultimate and Professional, it does feature file and printer sharing as well as permission settings and password protection. Windows 7 Professional Small businesses would appreciate Windows 7 Professional. It adds server networking features including Remote Desktop and file-system level encryption. Along with the improved Backup and Restore functions available on all editions, Professional has the option of backing up your files to a network. Windows 7 Ultimate Windows 7 Ultimate may be upgraded from Windows 7 Home Premium or Professional for a fee with Windows Anytime Upgrade. Windows 7 Ultimate and Enterprise editions offer BitLocker drive encryption for internal or external drives. A great utility for easily misplaced portable drives, once turned on this feature automatically encrypts all saved data. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_2.html 2/2  Editor's Note Windows 7 Environment Windows 7 includes numerous enhancements that make it an exceptional operating system. Some features listed below may only be available on certain editions of Windows 7. Security Defense against hackers and malicious software with User Account Controls (UAC) is now more flexible and less intrusive in Windows 7. Hard drives encrypted with Windows BitLocker Drive Encryption now includes portable storage devices like USB flash drives with Windows 7's BitLocker To Go. Security from malware and spyware with Windows Defender now provides a new "Clean System" feature for easy purging of suspicious files. Customizing levels of protection for different situations such as home, work or public setting, can now be easily accomplished with improved Windows Firewall. Visual Style Enhancing desktop management, Windows Aero provides visual effects like translucent glass and subtle animations. Windows taskbar now has pop-up preview thumbnails of all minimized windows as you mouse over. Click it, and the window restores. Right clicking on a program icon on the task bar will give you a "Jump List" of recently accessed documents, or web pages. Multimedia With Windows Media Center users can watch, pause, and record live TV or schedule a recording in advance . Windows 7's improved Windows Media Player 12 enables streaming from your computer to other PCs, TVs or stereos on your home network. Miscellaneous To list all the enhancements in Windows 7 is not easily done. A visit to the Windows web site will answer most questions. Blogs or forums will add others opinions on the myriad innovative features available in Windows 7. Minimum Requirements of the Windows 7 Operating System For a computer to accommodate and successfully support Windows 7, it must first meet the following hardware requirements: A 1GHz (or higher) 32 or 64-bit computer processor 2GB (64-bit) or 1GB (32-bit) of memory (or higher) At least 20GB (64-bit) or 16GB (32-bit) of free hard-disk space. XP mode requires an additional 15GB DirectX 9 graphics device with WDDM 1.0 or higher driver Recommended minimum of 32MB or 128MB of graphics memory All versions except for Home Basic also require a WDDM driver, Pixel Shader 2.0 in hardware, and 32 bits per pixel A DVD drive for installation Requirements will vary depending on which edition of Windows 7 and what applications you will be running. Windows 7 Upgrade Advisor is a download available from the Microsoft web site that will determine if your PC meets the specified requirements and will provide more specific information. Click to learn more. (http://windows.microsoft.com/enUS/windows/downloads/upgrade-advisor)
134320-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_3.html 1/4 Lesson 45: Windows Vista, 7, and 8  45.3 Windows 8http://www.google.com/ (http://www.google.com/) Microsoft released Windows 8 in October, 2012. With the release of Windows 8, Microsoft introduced new functionality including a new lock screen, the Hybrid Boot mode, quicker startup through UEFI integration and the capability to produce live USB versions of Windows. In addition, Microsoft introduced new changes including, but not limited to the Start screen, a touch-optimized Windows shell and enhanced Security features. Windows 8 Start Screen With Windows 8, Microsoft also introduced a new platform for developers to develop apps with an emphasis on touchscreen input along with support for USB 3.0 and advanced format hard drives. Lastly, Microsoft introduced enhancements enabling the integration with online services and a Windows Store, which is an online store for downloading and purchasing new software. New authentication methods designed for touchscreens such as PINs and picture passwords are also included in Windows 8. Microsoft incorporated enhanced antivirus capabilities in Windows 8 within the Windows Defender application. In addition, Windows 8 includes SmartScreen filtering and Family Safety, which offer activity reports and safety controls. Windows 8 supports the UEFI specification known as secure boot, which prevents unauthorized programs such as bootkits from infecting the device's boot process. A public-key infrastructure is used by secure boot to verify the integrity of the operating system. In addition, with the release of Window 8, system recovery is now available through the Refresh and Reset functions. System recovery is also available from the USB drive. Access to online services is provided by Windows 8. This access enables the synchronization of applications and settings between devices. In addition, Windows 8 comes with a client app for the Microsoft's SkyDrive cloud storage service. The cloud storage services enables users to save apps and files directly to SkyDrive. Internet Explorer 10 is included in Windows. An added feature to Internet Explorer 10 is enhanced support for mobile broadband along with an airplane mode setting to globally disable all wireless connectivity. The Task Manager in Windows 8 contains a processes tab. This tab has the option to display fewer or more details related to the applications that are running in addition to the background processes. The processes tab option also includes a heat map utilizing different colors to specify the level of resource usage, network and disk counters, which are grouped by process type and friendly names for the processes. Within the Windows 8 environment, Windows Explorer contains a ribbon in place of the command bar. In addition, the file operation dialog boxes provide more detailed statistics along with the ability to pause file 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_3.html 2/4 transfers and manage conflicts when copying files. The Storage Spaces permits the combination of varying sizes of hard disks into virtual drives. Lastly, the File History permits incremental revisions of files to be backed up to and restored from a secondary storage device. Processor 1 GHz clock rate IA-32 or x64 architecture Support for PAE, NX and SSE2 x64 architecture Second Level Address Translation (SLAT) support for HyperV Memory (RAM) IA-32 edition: 1 GB x64 edition: 2 GB 4 GB Graphics Card DirectX 9 graphics device WDDM 1.0 or higher driver DirectX 10 graphics device Display screen N/A 1024×768 pixels Input device Keyboard and mouse multi-touch display screen Hard disk space IA-32 edition: 16 GB x64 edition: 20 GB N/A Minimum hardware requirements for Windows 8 Windows 8 Editions Windows 8 is available in four editions: Windows 8, Windows 8 Pro, Windows RT, and Windows 8 Enterprise Windows 8 The basic edition of Windows 8 is for the IA-32 and x64 architectures and is targeted for the home market segment. This edition provides the basic new Windows 8 features including: The Start screen The Windows desktop Live tiles Windows Store, Internet Explorer 10 Connected Standby Microsoft account integration Windows 8 Pro This edition includes all the Windows 8 functionality in addition to such features as the capability to receive Remote Desktop connections and participate in a Windows Server domain. Additional features in Windows 8 Pro include: Encrypting File System Hyper-V Virtual Hard Disk Booting Requirement Minimum Recommended 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_3.html 3/4 Group Policy BitLocker and BitLocker To Go Windows 8 Enterprise Windows 8 Enterprise includes all the functionality features of Windows 8 Pro in addition to assisting with IT organization. This edition is available to Software Assurance customers along with MSDN and Technet Professional subscribers. Windows RT Windows RT is pre-installed and is only available on ARM-based devices such as tablet PCs. This edition includes the touchoptimized desktop versions of the basic set of Office 2013 applications. Windows 8 vs. Windows 7 The key differences between Windows 8 and Windows 7 include: Improved Windows 8 touch Windows 8 Start screen Improved multiple monitor support Introduction of Windows 8 charms Windows 8 Search and Social Windows 8 ARM support Windows Store Windows 8 cloud integration Windows 8 Metro Interface If you aren't new to Windows and are familiar with previous versions, at first glance, the Windows 8 Metro Interface can be quite daunting. There will be some work-arounds that will have to be learned to navigate as proficiently as in the past. Along with this a whole new set of terminologies have been introduced to describe the desktop and Start menu features. Tiles - Windows 8 icons on the Start screen and on All Apps menu. Live tiles display updating information like weather. Start Screen - the equivalent of what was previously the Start menu. Charms bar - quick access to: Search – opens up an Explorer window with active Search box Share – opens up Network Connections Start – opens the Start Menu Devices – opens Device Manager Settings – opens Control Panel Windows Apps - software designed to run on the Windows 8 interface. App Selector - used for switching between programs. Currently running programs are displayed on the left edge. One of the innovative features about the new Windows 8 Metro interface is its support for touchscreen tablets. If you don't have a touchscreen to take advantage of the Windows 8's gesture capabilities, the mouse is still used. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson45/lesson45_3.html 4/4 Some basic navigation can be performed following these steps: Start: Left click the mouse on the tile in the bottom left corner. All Apps: Right click on the Start screen to access the All Apps button on the App bar. Multitask Quick Swap: Left clicking the mouse in the top left corner gives access to the desktop or last viewed application running. App Selector Bar: Left click the mouse in the top left corner and mouse down the left side of the screen to access running apps. Charms: Hover the mouse to the top or bottom right corner. Power User Navigation: Right click the mouse on the tile in the bottom left for a pop-up menu consisting of quick access links such as Task Manager, Control Panel, Device Manager.
134420-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson46/lesson46_1.html 1/2  Editor's Note Lesson 46: Mac OS X, Unix, and Linux  46.1 Mac OS X The major difference between PCs and Macs is their operating system. Macintosh’s operating system—Mac OS X —is unique to Apple computers. OS X Mavericks (version 10.9) is the 10th key release of the OS X desktop and server operating system for Apple’s Macintosh computers. The release was publicized on June 10, 2013 and made available worldwide as a free update on October 22, 2013 via the Mac App Store. The updated operating system includes enhancements to the battery life as well as the Finder, the default file manager used on OS X. For iPhone and iPad users, OS X Mavericks continues to feature iCloud integration, allowing users to store and access their music, photos, and apps from multiple devices. A hacked version of OS X called OSx86 is able to run on PCs. The adapted OS was created by an unknown programmer and is not supported by Apple. Though Apple’s modern computers are capable of running Windows via a dual boot or virtualization configuration, Apple has not currently announced plans to create a commercially available version of OS X that will run on a PC. Built on UNIX, Mac OS X is divided into two main files: System File and Finder. Together, these two primary files perform the following operating system functions: formatting disks, copying and erasing files, and running application software. In addition, the System File and Finder manage the user interface, file menus, and user-requested commands. A computer’s limitations are dictated largely by its microprocessor. Older Macintosh computers used Motorola-manufactured microprocessors such as the PowerPC G5. Motorola chips do not run DOS applications, consequently, Macintosh computers do not run DOS programs. In an effort to expand compatibility, OS X versions since Mac O/S version 8, are natively capable of reading, but not writing to, Windows FAT32 and NTFS files. Apple is increasingly moving away from their standoff approach to the PC community by creating applications such as ITunes and QuickTime that can run on Macs and PCs. In 2005 Apple switched from Motorola based microprocessors to Intel based chips such as the Core2Duo and Core i7; this change in system design allows for Apple users to be able to install and run Windows based operating systems with a special set of drivers called Apple BootCamp. Though Windows is not officially supported by Apple, the Windows Operating System can be run from a Macintosh either via a dual boot configuration or via emulation in OS X. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson46/lesson46_1.html 2/2  Editor's Note Mac Desktop The Mac OS X desktop uses the Aqua interface, which uses translucency and shadowing to provide depth. Aqua also uses lots of animation to make the OS X more user friendly. Folders that are opened and closed are whisked into the dock Widgets, which are miniature applications that can be created to perform searches and lots of other functions, appear on the desktop with a ripple effect. Sliders rotate program icons to access running programs. Mac OS X's desktop is constantly being improved as new versions are created. Apple Computers were the first to incorporate a graphical user interface into its Macintosh computers. This interface was first developed by Xerox. Software Since Mac OS does not support DOS-based software, Macintosh computers require Apple-specific, Apple-compatible software. As a result, Macintosh users are limited to software written specifically for Mac OS. With the increased popularity of Macs, more and more software developers are finding it economically worthwhile to develop programs for PCs and Macs. Apple Popularity While the versatile and easy-to-use Macintosh has always drawn its share of loyal Mac-advocates, the Macintosh computer has not always enjoyed popularity equal to PCs. Fast forward to today however and Apple products have experienced a huge surge in popularity thanks in large part to its development of the iOS mobile operating system and accompanying mobile devices such as the iPod Touch, iPhone, and iPad. These devices blend mobile hardware and form factors with traditionally computer based functionality such as web browsing, multimedia playback, and file storage. Initially, Macintosh computers lacked speed. IBM text-based DOS programs were faster than the graphical Macintosh. Some DOS and UNIX text commands initiate sequences and automate tasks that are absent in the Macintosh operating system. Consequently, a lot of software was written in a language Macintosh computers could not read. Macs are premiere desktop publishing and graphics design computers. Apple's line of personal computers— the iMac, Mac Pro, MacBook, and MacBook Pro — have dramatically increased Apple's standing in the computer industry. Apple's Macintosh has a rich history. Its graphical user interface made the Macintosh fun, easy to use, and popular with many computing newcomers. The Macintosh's excellent reputation for supporting high quality graphic software programs makes it the computer of choice for most graphic designers.
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134620-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson46/lesson46_2.html 1/3 Lesson 46: Mac OS X, Unix, and Linux  46.2 Unix, Linux, and X Windows Two operating systems relatively unfamiliar to casual computer users: UNIX and its newer counterpart Linux are slowly making their way into the mainstream. Continued technological improvements have made the advantages of Linux and UNIX accessible to a greater number of computer users. UNIX Developed by AT&T for minicomputers, the UNIX operating system has been around since 1969. Early UNIX versions were used exclusively by scientists, engineers, and computer programmers. Today, UNIX attracts a wide audience of minicomputer, microcomputer, and workstation users. UNIX is a multi-user, multitasking operating system that can run single workstations or act as a server’s master control program. UNIX Advantages UNIX is a portable operating system and its software can easily be moved from one type of computer to another. UNIX offers versions for several hardware platforms and provides accessories for switching between them. For example, some UNIX versions can be used with microcomputers, minicomputers, mainframe computers, and even supercomputers. The majority of today’s operating systems do not extend far beyond the microcomputer. UNIX has further advantages over other operating systems: simultaneous multitasking, multiprocessing, and networking. Multitasking allows UNIX to perform several tasks at once. Multiprocessing makes it possible for UNIX to run several programs simultaneously and independently of each other. UNIX Disadvantages 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson46/lesson46_2.html 2/3 Since UNIX was originally created for the minicomputer, its features favor computer programmers. Other computer users are sometimes unsatisfied with UNIX features. Limited business application software hinders UNIX’s general market acceptance. Businesses depend on off-the-shelf computer applications, unfortunately few off-the-shelf applications have been written for UNIX. One important disadvantage is the lack of a UNIX standard. There are several different shells (also known as interfaces) of UNIX including Korn, C and Bash. A UNIX-based application that runs on one UNIX shell may not run successfully on another shell. A number of companies are working to create a standard so that all UNIX shells will be compatible. UNIX is still quite popular with engineers and people who conduct research projects, but, for the average user, long and complex commands make UNIX complicated to learn. Even so, many industry experts expect UNIX, with time and development to eventually become one of the most popular microcomputer operating systems. Linux Another popular operating system is Linux. A specialized UNIX version, Linux was created when Finnish computer science student, Linus Torvalds turned a popular classroom teaching tool into the Linux operating system. Linux is freeware—software available for public use at no cost. Considered a very stable operating system, Linux is increasingly popular as an Internet Web server operating system. Linux is unique in its public distribution and adaptability. Users’ enthusiasm for a free operating system, and their ability to create new features or solve system bugs have contributed to Linux’s popularity. With Linux, users can change and customize software to fit their needs and can take advantage of many useful UNIX-based features. Linux isn’t for every computer user because Linux users are limited by many of UNIX’s challenges. A good understanding of the UNIX operating system’s complex commands is required. However, as Linux continues to develop, its popularity is expected to grow as a network server and desktop operating system. Several distributions of Linux are available. Linux is distributed by Debian, Red Hat, Caldera, Slackware, and S.U.S.E. One easy and popular method to get Linux is by downloading it for free from the Internet. Linux distributions are also available for purchase from computer stores. Each Linux distribution offers the same Linux OS, but distributions differ in the software and support that accompany their distribution. For example, each distribution includes its own installation software and various other applications. It is important to note that software packages vary from distribution to distribution. The advantage to buying a Linux distribution is that you will also receive a guidebook and free technical support. Linux Features Linux is similar to UNIX because it is a multitasking, multi-user operating system. This means that Linux can accommodate multiple users, simultaneously running multiple applications. Linux requires a "log in" name that identifies the user to the computer. A log-in name increases system security by assuring that only the proper user can access a certain Linux machine. Linux also assigns a "host" name to the computer on which it runs. Host names are used to identify stand-alone computers as well as computers that are part of a network. Many users enjoy Linux's naming feature because it adds some character to their computer. The X Window System 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit12/lesson46/lesson46_2.html 3/3 The X Window System is a GUI system designed by the Massachusetts Institute of Technology (MIT). X Windows System has become UNIX's graphical user interface standard. In addition, it has been estimated that nearly every UNIX workstation in the world runs a version of the X Window System, facilitating UNIX's growing popularity. In addition to UNIX, X Windows runs under all major operating systems. X Windows also permits a user to run applications from other computers on a network while viewing the output on their own screen. X Window works by generating a simple window that can later be enhanced with other GUIs. However, X Windows does not require a running application in order to conform to a GUI standard. The window manager component of the X Windows GUI allows multiple resizable, "relocateable" X Windows to be viewed on-screen at the same time. There are also modified versions of X Windows that function with Linux.
134720-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_1.html 1/1 Lesson 47: Communication and Professionalism  47.1 Effective Communication There's a good reason that we were born with two ears and one mouth, so the first rule in communicating is to use those organs in correct proportion. Effective communication occurs only when you are able to truly listen to the other person to understand their point of view and the subtle "unspoken" subtexts and body language they use. Most workplace conflicts occur through miscommunication, so the more skilled you become in this area the better. Books, workshops, and courses in communication skills can increase your value greatly. Certain communication habits are harmful and should be avoided at all costs: continual complaining soon becomes irritable, close-minded arguing gets nowhere, and gossip creates mistrust and negativity. Profanity, excessive slang or other crude, derogatory, biased or vulgar comments may seem acceptable with friends, it but doesn't support your image when dealing with a customer or a colleague. On the other hand, positive listeners who communicate sincere interest in others and in work projects are always appreciated. Another aspect to communication relies on gaining knowledge about personality, cultural, and generational differences between people. Of course, this implies greater self-awareness as well. Many companies provide training in this area, but numerous books and educational settings provide insights. Cultural sensitivity Cultural sensitivity is important in maintaining a cohesive working environment and running a successful business. For the working environment to be harmonious and efficient, employees must possess cultural sensitivity by being respectful and considerate to each other despite cultural differences. Cultural sensitivity skills are also essential when dealing customers and clients that may have diverse backgrounds and heritages. Examples of culturally sensitive would be not to perpetuate stereotypes and not to make assumptions about people behavior based on country of origin or religion.
134820-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_2.html 1/2 Lesson 47: Communication and Professionalism  47.2 Active Listening and Avoid distractions Active Listening A major component of getting along with people; in fact, arguably the major component in getting along with people is the art of listening. Yet listening is far more than merely showing up for a conversation and being quiet. Many are trained to be passive listeners, and many more are selective listeners, hearing only what they want to hear and missing most of the message. The old trick of "fake it till you make it" won't work with listening-unless the speaker is denser than granite, he'll soon uncover a person who doesn't fully listen. What is required is active listening. The first key is that you must actually want to listen. If insincere about this, your body language or some other inadvertent signal will give you away. Following are required behaviors for active listening: Unwavering Eye contact Sincere facial expressions and interested looks Patience – Do not interrupt the customer. Head nods to indicate understanding Verbal acknowledgments: Questioning to draw out more information Encouraging signals - "OK," "Yes," "I see," "Uh-huh," "Really," "Wow," etc. Speaking up when confused about the message after the customer is finished. Summarizing your understanding of the message. Acknowledging and exploring the emotions being expressed. Avoid distractions To demonstrate proper communication and professionalism, you should avoid distractions such as taking personal calls, interrupting your workday with personal business, and talking to co-workers while interacting with customers. Limit personal calls during the work day to only those that are absolutely necessary. Your personal calls with be distracting to your coworkers and you will appear unprofessional to customers. Your co-workers or customers should not overhear your personal problems or arguments with your family or friends. Instead use your lunch break to conduct your personal business. Ask your family and friends to call you when you are on your lunch break. It is best to leave company premises to make sure that your conversations are not within earshot of co-workers or customers. Alternatively, ask them to text or email you instead if they have a problem or question during your workday. It is important that your personal life does not cause interruptions to your ability to get your work done. Your employer will not appreciate you using company time to put your personal affairs in order. Also your co-workers will not appreciate that you are conducting personal business during work hours when they are busing working. It is best to take a day off if you have a number of things to do or have a tricky situation such as a legal issue. Do not inform or involve your co-workers and bosses in your personal situations. They will not appreciate being drawn into any personal drama nor should you want to become the subject of gossip in the office. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_2.html 2/2 When you are interacting with customers whether on the phone or in person, it is important to give them all your attention. It is important that you do not have a side conversation with a co-worker while interacting with a customer unless you are asking for the co-worker’s help to solve the customer’s problem. Customers will feel that they are not important to you if you do not give them your full and undivided attention. If you do need help from a co-worker and the customer is on the telephone, ask the customer if you can put him or her on hold before doing so. If the co-worker can help the customer directly, first make sure that the co-worker is ready to take the call and then inform the customer that you will be transferring the call to your co-worker who will provide further assistance.
134920-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_3.html 1/4 Lesson 47: Communication and Professionalism  47.3 Conflict Resolution When someone approaches the technology area for help, it is not always easy to resolve the situation right away. Often times, customers will be frustrated and confused about a problem. If the problem isn't resolved the first time, it can lead to even more conflicts between technical help and the customer. Preparing yourself for these situations will allow you to easier help customers with their problems. You must adopt an understanding and respectful approach, despite the customer's complaints. When approaching the problem or issue with the customer, it is important to maintain a positive attitude, which allows you more flexibility when helping them. In turn, the appropriate environment will be reflected during the interaction with the customer. Dealing with conflict resolution and responding neutrally is important for every technician. Not only will it affirm that you are willing to help, but that you understand and will provide the necessary support. Affirming Customer Needs The first step is to recognize when a conflict is developing. Signs include: Customer is using an angry, sarcastic, or negative tone Customer is speaking faster and gestures are frantic Customer’s speech volume is increasing Customer is using emotional words (displeased, tired of, frustrated, upset, unhappy, critical, etc.) The next step to take is to recognize where the customer is coming from. Don’t minimize the customer’s problem. Try to be understanding of what is happening, and by do so you will have an easier time helping them to solve their problem. This can be as simple as an affirmation to communicate that you understand. Allowing the customer to vent their problem will help them calm down so that you can begin the problem solving process. Once the complaint has been lodged, you can help the customer feel more at ease. This means that you will want to respond to the complaints in a way that makes them feel that the problems will be overcome and resolved. Use active listening to let the customer know that you understand why their problem is causing frustration, and then assure them that you will help them solve their problem. If the problem concerns non-responsive technical assistance or ineffective technology, walk through the situation. It is important that you show your concern and help them to help lessen their frustration. If the problem needs to be escalated to a higher level technician for more specialized help, explain why you are transferring them to a new technician and assure the customer that they will receive better help. Make sure that the customer knows that you will always be available if they need to contact you again about this problem or any other problems they may encounter in the future. Paraphrasing Just like it sounds, paraphrasing is simply re-stating the main idea of the speaker's conversation to check whether your understanding is correct. This time use your own words to verify the content of the message. The paraphrase should be brief. A sentence or two at the most that ends with an inquisitive tone. Again, no judgments are made -- you are seeking confirmation that you have understood the message accurately. Starter phrases include: 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_3.html 2/4 What I'm hearing you say is… What you're saying is… If I understand you correctly… Sounds like you're saying… Verifying Understanding After primarily listening and making sure that the speaker freely expresses the message, you must now go on to determine that you have perceived what the customer really means, and checking to make sure that you understand the real meaning and are not operating under false assumptions. Reflecting feelings Reflecting feelings is an honest attempt to mirror back the emotions you perceive are being expressed. Guidelines: Identify and state the emotion being expressed Use the word "you" to identify the speaker and not yourself Make it sound like a question since you are checking. Use phrases like "Is that correct?" if necessary. Responding to Positive Feedback Many are embarrassed when complimented, but pretending that you don't deserve praise is not the appropriate response. False modesty is often annoying and actually doesn't speak well of you, giving off the impression that you are very low in confidence. People will be less likely to give positive feedback when you habitually negate it. So, what is appropriate response? Say "thank you." Accept the praise and show appreciation for the feedback A benefit of positive feedback is that it can give a confidence boost, and often encourages employees to continue positive habits. You've heard the cliche "If it ain't broke, don't fix it." That saying applies here, so don't radically change what you're doing well. Correct Responses to Complaints After affirming the customer, you can start working towards the correct resolution. A customer is more likely to return when complaints are resolved. The most important thing to do when a customer complains is to avoid getting upset at them. Specifically, respond in a caring manner, and avoid acting as though it is not your problem and shrugging off the complaint. This would only make them angrier and cause more conflict. For example, if you respond to a complaint by first listening and then assure them that you will find a solution, the customer will be more satisfied with the product. On the other hand, if you indicate that this is just the way that the product is made (and not really your problem), they will likely return the product, complain to everyone they know, and then go to your competitors to see if they can get the correct help. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_3.html 3/4 As you can see, your attitude and response makes a huge difference in finding an agreement or sending a customer to the other side. Making sure that you understand and meet the customer half way will allow you to provide the best results. Occasionally, some customer complaints are not valid. Understanding when you can or cannot help a customer is also important. For instance, for non-technical issues, you will want to explain alternatives and let them know why you can't help them. A friendly attitude allows them to feel better about their situation, even if it is one that you can't resolve. Even if the customer is wrong, you cannot blatantly tell them that they are wrong. This will only cause them to continue to attack and feel as though they are not being listened to. If a customer comes in with an unresolvable problem or non-issue, you want to take the same approach by giving them an alternative solution. For example, you can respond by listening and acknowledging that you understand. This allows them to immediately feel as though they are being listened to and that you are going to solve the problem. After this, you can direct or guide them to a way to find a solution. If it is something that you can't fix, you can send them to someone who might be able to. The more knowledge and alternatives you are able to give them on the topic, the more likely they will be able to see a different route and will feel like there is a solution. The main concept in conflict resolution is to provide a customer with solutions, knowledge and alternative answers. Even if the problem is not directly linked to anything that you can do or is not a legitimate complaint, soft skills can be used to provide alternatives. This will stop the customer from bringing up conflicts and will allow you to remain in a neutral position while helping them. Be sure to decompress and de-stress at the end of a particularly difficult situation at the end of a long day. Remember that negative comments from irate callers are never personal. Offer Different Repair or Replacement Options Your company may offer different repair options for customers. Consult your company’s policy on offering repair of components beforehand so you are prepared to explain the options and their costs to your customer. If the component cannot be repaired, it may be appropriate to offer the customer a replacement. Your company should have a policy in place that explains your options. For example, your company may offer replacement of components for free of charge anywhere from 30 days to one year after purchase. Check first with your supervisor before offering a replacement option if you are unsure of your company’s policy. Timely Resolution With the 8 step model, you can identify problems and move forward with troubleshooting. However, you will also want to consider how this relates to the complete job role as a help desk technician, as it include working with customers and analyzing the technology. First you want to have a timely resolution. This means that whenever a ticket comes in from a customer, you will need to determine how serious it is. By doing this, you can solve the more serious problems in a timely fashion while taking care of the smaller problems in time. One way to prioritize and evaluate tickets is to first look at the time frame that the tickets have come in. If you have customers that have been waiting for a longer period of time, you will want to look at the issues that they have first. This allows you to define what the problems are and provide a way to meet the demands. Once you begin looking at the tickets, you can devise a system for faster and easier results. For example, tickets for less serious problems can be re-directed to the FAQs sheet to easily guide the customer. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_3.html 4/4 Network technicians typically receive troubleshooting requests all at once instead of one at a time. The very first step in prioritizing is to access the severity of the problem. The order in which problems are addressed may correspond to the following table: 1. Severe Total network failure 2. Critical Partial, large network failure 3. Somewhat Severe Small network failure 4. Somewhat Critical Total workstation failure 5. Non Critical Partial workstation failure 6. Minor Intermittent minor problems Some companies use a database to track and prioritize all troubleshooting issues. Others use a white-board. You can determine exactly what a customer needs and how serious the problems are by the “symptoms” that they describe to you. For example, if a customer tells you where the network is shutting off or having difficulties, then begins to tell you about the specific symptoms that are related to it, it will be easier to find a solution. If there is a problem that you are not familiar with, finding the solution to the problem may take more time. If needed, inform the customer if you need to leave and provide the time that you expect to return and if for some reason you are not able return at the expected time, contact the customer and provide a new return time. You will also want to make sure that you can balance your work load, allowing you to take care of these more serious problems within a given time frame.
135020-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_4.html 1/2 Lesson 47: Communication and Professionalism  47.4 Document the Services and Solution to the Problem It is vital to document every problem, large or small and exactly what was done to fix it because problems tend to resurface. Documentations can save time and reduce the chance of repeating the same mistakes as well as provide records of the services provided to the customers. The documentation is often assembled into a customer service database for quick reference. Be sure to include the following information to ensure that database entries are valuable: A description of the conditions surrounding the problem and the problem symptoms Whether the problem could be reproduced Describe the possible repairs or replacements options The solutions attempted The final solution Anything that important for the next person who may encounter the problem. Assume that you will not be available to help solve the problem the second time around. Improving Customer Satisfaction Customer focused companies initiate as many levels of communication with customers as possible. This helps businesses learn more about what needs to be offered and whether the customer has received the right technology and assistance. Respect for privacy and customer property must be maintained for all surveys and assistance given. Customer satisfaction can be improved in the following areas: Customer surveys provide invaluable information on product and service quality and problem areas. This is also true of surveys designed to elicit information about help desk support quality and effectiveness. Surveys also highlight customer needs to ensure that the company will continue to provide a valued and needed product or service. Informational resources or FAQs are one of the cheapest, quickest, and most effective methods of dealing with common customer problems. FAQs can be online or printed and included with the product manual. Information areas provide one of the easiest and best technique to assist customers. Setting up websites, automated response systems, technical help desks, and other support areas allow customers to find more than one way to get the information or assistance that they need. All employees that deal with customers (marketing, sales, and help desk technicians) are trained to ensure that they have the skills necessary to provide a specified level of service. This includes providing effective help, making sure that all problems have been dealt with before ending a conversation, thanking customers for the chance to help them, and other rules that ensure a high level of assistance. Vacations, excellent health plans, health club packages, stress reduction techniques and amenities may also be provided to help desk technicians cope with the higher level of stress that they encounter. This will ensure that technicians are able to continually provide respectful, professional, and cheerful assistance. In order to provide privacy and respect for property, guidelines for employees as well as policies that ensure privacy must be developed and all employees must be aware of them. This is especially true when using a remote desktop or when trying to fix an individual's personal computer. Access to personal files can be a cause for 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson47/lesson47_4.html 2/2 concern, and customers need to know that their personal information is safe and that a business can be trusted to protect their information. Property must also be returned in the same condition it was delivered. Customer Satisfaction Rules There are many rules that are set in place to ensure a high level of service and customer satisfaction. These vary slightly between each company, but some general examples of customer interaction rules include: Always take ownership of customers' problems and ensure that the problem will be solved. Always maintain a positive, helpful, and professional attitude. Treat all customers with respect at ALL times. Never blame the customer for anything. Never blame the problem on the company. Always focus on the solution to the problem. Always ask the customer if the problem has been resolved to their satisfaction and whether they have any other problems before ending a call. These rules should be communicated very clearly when you begin working at a support company. Be sure to internalize these rules since they will guide you in every customer interaction you have. These rules are not flexible regardless of the problem or how irate a customer may act. You will need to maintain a professional attitude and resolve the problem for every single customer. This ensures the highest possibility of customer satisfaction and builds loyalty, which helps your company succeed in its goals and helps you succeed within your company.
135120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_1.html 1/1 Lesson 48: Workplace Security Policy  48.1 Protecting Confidentiality Companies often have information about customers that should be kept confidential. That information could be on your computer or a company server or be a printed document. Regardless of its format or where it is stored, it is your responsibility as an employee of your company to protect that information. Customers expect that their information is confidential and will not be shared; and laws protect customers by fining companies that breach their trust. It is very important that you take all precautions to prevent unauthorized access to files and do not disclose any information about customers to anyone outside of your company. If you are accessing a customer’s network, server, etc. to perform work for them such as troubleshooting, first get the permission of the customer. If you are troubleshooting, you probably have obtained an administrator-level username and password; it is critical that you do not distribute those usernames and password even to your own co-workers unless you have permission from the customer.
135220-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_2.html 1/2 Lesson 48: Workplace Security Policy  48.2 Dealing with Prohibited Activities Employees sometimes download, post, or share content that is inappropriate for the workplace using their work computers. Examples of prohibited content could be pornography, offensive materials, competitors’ information, etc. Employees may also perform activities that hurt companies such as sharing confidential information with competitors or posting opinions on social media sites using their work identities. In addition to employees, external bodies may hack into a company’s network and post inappropriate content or conduct harmful activities such as posing as a company employee. All of these scenarios must be dealt with swiftly. First Response is the term used to indicate the immediate activities that must be done as soon as prohibited content or activities are reported or suspected. First Response has three phases: 1. Identifying the prohibited activity 2. Reporting through proper channel 3. Data and Device Preservation Identifying the prohibited activity Identify which company policy or law prohibits this content or activity, you will need to identify the following for data and physical security: Names Purposes Characteristics Names, purposes, and characteristics of physical security devices and processes include the following: Access Control to PCs, servers, laptops, and restricted spaces Access Control to Hardware Access Control to Operating systems Names, purposes, and characteristics of data and physical security include the following: Password management Encryption technologies Securing workstation such as hardware and operating system Data access with the basic local security policy Data migration Backups 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_2.html 2/2 Data/remnant removal Names, purposes, and characteristics of access control and permissions include the following: Permission actions such as read, write, change, and execute in addition to restricted spaces and components Permission levels, types such as file systems and shared Groups Accounts including user, admin, and guest Names, purposes, and characteristics of wireless security include the following: Access points such as MAC filtering Modify default username and password Bring firmware up to date Firewall Deactivate DHCP/use static IP Modify SSID from default Deactivate SSID broadcast Wireless encryption such as WEP and WPA Client configuration Names, purposes, and characteristics of hardware and software security include the following: File system security such as FAT32 and NTFS Software firewalls Smart cards/biometrics such as chips, scans, key fobs and cards Hardware deconstruction/recycling Malicious software protection such as viruses, adware, grayware spam, spyware, Trojans and worms Authentication technologies such as username, password, smart cards and biometrics Reporting through proper channel Once you have identified the prohibited content or activity, you must report it to the proper authorities. Start with your manager. He or she can help you report the activity. If the violation is of a law, your company must contact the authorities so that the company does not get in trouble for failure of reporting a crime. If the violation is only of company policy, your manager should know which department to contact – legal, IT, human resources, etc. Data and Device Preservation All data and hardware involved in the incident, such as an employee’s computer or a web server must be secured. This step may involve confiscation of devices which is often necessary to preserve all evidence.
135320-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_3.html 1/3 Lesson 48: Workplace Security Policy  48.3 Documenting Incidents Documentation is invaluable when dealing with prohibited activities or incidents. Document the steps you took to identify, detect, and report the problem as well as secure data and devices. Your company may have a trouble ticketing system for such an issue. Your company may also have an Incident Response Plan (IRP). An IRP outlines what steps are necessary and who is responsible for determining how to handle a situation. If your company does not have an IRP, suggest that one is created. Sample Incident Response Plan 1. The person who discovers the incident will call _____________ (department, group, or particular person such as Help Desk, IT Security, CIO, System Administrator, or Network Administrator). 2. If the above department/group/person does not respond within x hours, contact ___________. 3. Prepare to provide the following information: Your name and contact information Type of incident How the incident was detected Data or devices that were compromised Known damage Severity of the potential impact to critical business activities Suspected or known perpetrators How and where evidence was collected and preserved 4. Contacted members of the response team will meet or discuss the situation over the telephone and determine a response strategy. Is the incident real or perceived? Is the incident still in progress? What data or property is threatened and how critical is it? What is the impact on the business should the attack succeed? Minimal, serious, or critical? What system or systems are targeted, where are they located physically and on the network? Is the incident inside the trusted network? Is the response urgent? Can the incident be quickly contained? Will the response alert the attacker and do we care? 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_3.html 2/3 5. An incident ticket will be created and categorized: Category one - A threat to safety Category two - A threat to sensitive data Category three - A threat to computer systems Category four - A disruption of services 6. Team members will establish and follow one of the following procedures basing their response on the incident assessment: Worm response procedure Virus response procedure System failure procedure Active intrusion response procedure Inactive Intrusion response procedure System abuse procedure Property theft response procedure Website denial of service response procedure Database or file denial of service response procedure Spyware response procedure 7. The team may create additional procedures. If there is no applicable procedure in place, the team must document what was done and later establish a procedure for the incident. 8. Team members will use forensic techniques, including reviewing system logs, looking for gaps in logs, reviewing intrusion detection logs, and interviewing witnesses and the incident victim to determine how the incident was caused. Only authorized personnel should be performing interviews or examining evidence, and the authorized personnel may vary by situation and the organization. 9. Team members will recommend changes to prevent the occurrence from happening again or infecting other systems. 10. Upon management approval, the changes will be implemented. 11. Team members will restore the affected system(s) to the uninfected state. They may do any or more of the following: Re-install the affected system(s) from scratch and restore data from backups if necessary. Preserve evidence before doing this. Make users change passwords if passwords may have been sniffed. Be sure the system has been hardened by turning off or uninstalling unused services. Be sure the system is fully patched. Be sure real time virus protection and intrusion detection is running. Be sure the system is logging the correct events and to the proper level. 12. Documentation — the following shall be documented: 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson48/lesson48_3.html 3/3 How the incident was discovered. The category of the incident. How the incident occurred, whether through email, firewall, etc. Where the attack came from, such as IP addresses and other related information about the attacker. What the response plan was. What was done in response? Whether the response was effective. 13. Evidence Preservation — make copies of logs, email, and other communication. Keep lists of witnesses. Keep evidence as long as necessary to complete prosecution and beyond in case of an appeal. 14. Notify proper external agencies — notify the police and other appropriate agencies if prosecution of the intruder is possible. List the agencies and contact numbers here. 15. Assess damage and cost — assess the damage to the organization and estimate both the damage cost and the cost of the containment efforts. 16. Review response and update policies — plan and take preventative steps so the intrusion can't happen again. Consider whether an additional policy could have prevented the intrusion. Consider whether a procedure or policy was not followed which allowed the intrusion, and then consider what could be changed to ensure that the procedure or policy is followed in the future. Was the incident response appropriate? How could it be improved? Was every appropriate party informed in a timely manner? Were the incident-response procedures detailed and did they cover the entire situation? How can they be improved? Have changes been made to prevent a re-infection? Have all systems been patched, systems locked down, passwords changed, anti-virus updated, email policies set, etc.? Have changes been made to prevent a new and similar infection? Should any security policies be updated? What lessons have been learned from this experience? Chain of custody Chain of custody is the structured handing of evidence from one person to another to ensure that the evidence is not compromised or lost. When you begin to document evidence, you must keep track of that evidence at all times and show who has it, who has seen it, and where it has been. Lock up the evidence in a safe, locked cabinet, or locked office. The evidence must always be within your custody, otherwise there may be a case with tampering which would compromise the case.
135420-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_1.html 1/3 Lesson 49: Safety at Work  49.1 Computer Safety About 40 million American workers spend the day working on computers, and this relatively new addition to the modern workplace has created some ergonomic considerations for employees. Some common and easily correctable conditions can arise when you spend too much time glued to your computer monitor. Hazards and Solutions in the Modern Office A few simple adjustments can make the difference between a comfortable workstation and one that sends you home with eyestrain or an aching back. Problem: Wrist Pain Wrist pain (Carpal Tunnel Syndrome) is becoming more common with workers spending many hours at computer terminals. Following the suggestions for preventing back pain will be helpful. Additionally, take steps to create the best ergonomic environment with your workstation. Solutions: Maintain ideal typing posture by placing the keyboard below your seated elbow height and sloped slightly away from you to fix the keys in “neutral” position. Adjust your chair so that you are sitting at a 90 degree angle. Raise or lower your chair so that your elbows form a 90 degree angle with your hands comfortably on the keyboard. Hold the mouse gently, and avoid using a tight “death grip” on it. Allow arm movement when using the mouse and avoid using wrist rests. Take 10-15 minute breaks from typing each hour. Make tight fists and stretch your fingers several times. Vary your routine during the day. For example, mix typing activities with filing activities throughout the day. Problem: Back Pain Back pain can be caused by sitting at a desk or computer terminal. You may be suffering unnecessarily, and here are steps you can take to solve the problem: 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_1.html 2/3 Solutions: Protect your spine by using a good office chair, one that has lumbar support and armrests. Get up frequently and move around. Sitting for too long is a prescription for back pain. Adjust your chair so your feet are flat in the floor or on a footrest. Your arms should be at a 90-degree angle, so you can work without hunching your shoulders. Do a few simple stretches during breaks to relieve muscle tension, such as neck rolls, shoulder squeezes, and spinal twists. Get regular exercise outside of work. Yoga is especially good for increasing flexibility and strengthening back muscles, and it will improve your mental attitude as well. Use a telephone headset. This will relieve neck strain caused by holding the receiver between your ear and shoulder. Problem: Eyestrain Eyestrain is a common problem for frequent computer users. Some symptoms are dry, sore eyes, problems focusing, and neck, back, and shoulder pain. Solutions: 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_1.html 3/3 Place your monitor screen so that it is slightly below eye level. Make sure the screen is at least 20 inches from your eyes. Stand up and move around occasionally, at least once every hour. Taking a break to look at an object other than your screen occasionally will also help. Use a copyholder that can hold documents at the same level as the monitor screen. Use artificial tears, if needed, to keep your eyes moist. Clean the monitor screen frequently to remove accumulated dust. Keep your computer monitor perpendicular to office windows. Use lighting that is soft and glare-free. Office lighting around computer terminals should be slightly dimmer than lighting in other work areas. Get regular eye exams to maintain eye health and keep corrective lens prescriptions up-to-date.
135520-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_2.html 1/3 Lesson 49: Safety at Work  49.2 Stress Management Everyone is under stress of some kind in the workplace. It's up to you to manage your own stress load and remain productive since no one can perform this vital balancing act for you. Managing Work Stress There are many steps to take in and out of your workplace to help you minimize and cope with stress. These include: Make your physical environment as pleasing as possible. Decorate your office or cubicle tastefully with photos of family and friends, a favorite pen or mug, or add plants to your workspace. Small touches like this will soften the industrial feel of office space and make it more people-friendly. Place your desk so it faces the door. Not only is it good Feng Shui, but it also eliminates the unnerving feeling that someone is about to sneak up on you from behind. Remain on good relations with co-workers and supervisors. Stay away from those who spread malicious gossip and badmouth supervisors. Seek out people with positive and proactive attitudes. Address problems and misunderstandings promptly, before they have a chance to escalate. How you handle your life outside work can influence workplace stress. Meditation, journal writing, regular exercise, and enjoying time with family and friends are some ways to maintain a sense of balance that is crucial to handling life's difficulties. Dealing with Stress Stress (or tension) can make you feel uncomfortable, anxious, angry, or upset. A certain amount of stress can be expected in the workplace, but an inordinate amount makes you less productive. It’s important to learn how to deal with stress, so you can work effectively under pressure. Major sources of stress in the workplace come from two sources: deadlines and other people. Suggestions follow on how to deal with these two areas: 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_2.html 2/3 Deadline Stress This occurs when you fear that you can’t finish your task on time. Instead of allowing the fear to consume you, focus on ways to meet the deadline. Self-control, creative problem solving, and communicating clearly become important when dealing with this type of stress. Two suggestions: 1. Do one thing at a time - Concentrate on your work and break a large job into smaller tasks. Plan with your deadline in mind and check your progress. Worrying about the deadline only takes away energy from meeting the deadline. 2. Ask for help when necessary - Of course you want to meet your deadline without getting help from others; however, if you find that this is impossible, you must talk with your supervisor. The worst possible scenario is missing the set deadline without communicating the problem. The supervisor must be aware of the situation, so that he/she can either extend the deadline or find the necessary help to meet the deadline. People Stress Anyone working with other people will experience stressful situations. Disagreements and conflicts are inevitable whether you work in customer service or in a more isolated area. You can’t control how other people act, but you are in charge of your own feelings and how you handle them. A few suggestions to deal with conflict: Listen - Practice active listening to understand their point of view without judgment. Assume their view point is valid. Remain neutral - Explain your own point of view politely and in a neutral manner that is neither positive nor negative. Instead of saying, “That won’t work,” respond with “I don’t understand how that will work.” Negotiate - Find the facts of the situation, discuss the problem, and attempt to reach a mutually compatible solution. Often a compromise ends up being the best approach to the problem, by taking multiple viewpoints into consideration. Another way to deal with stress is to make it work for you. Although the “normal” responses to stressful situations are usually negative anger or fear reactions, these feelings only drain the energy from you. Counter the negative feelings with positive ones. Redefine your situation and make it “fun.” Some possible switches include: "This will help me learn." "I can handle this. I enjoy a challenge." "When I successfully handle this task, others will see how good I am." "I will be really happy when I meet this challenge." Finding other ways to deal with stress will help you become more efficient at work and much happier and healthier overall. In fact, one general “stress buster” that many use successfully is to simply live a healthier lifestyle. Eat more nutritious meals Exercise regularly Get plenty of sleep Enjoy extra-curricular activities and hobbies Take time to relax 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_2.html 3/3 Take care of your spiritual/emotional life
135620-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit13/lesson49/lesson49_3.html 1/1 Lesson 49: Safety at Work  49.3 Other Safety Issues While some work situations are inherently more hazardous than others, the Occupational Safety and Health Act of 1970 requires employers to provide workplaces free from serious recognized hazards. Employers must also comply with occupational health and safety standards. If you suspect that there is an unreasonable hazard present in your working environment, start by respectfully bringing it to the attention of your employer. He or she may be genuinely unaware that a specific hazard exists, so you should always give an employer the benefit of the doubt before taking further action. Employers can contact the Occupational Health and Safety Administration (OSHA) for information about how to improve working conditions. In cases of ongoing, unaddressed workplace hazards, employees have the option to file a complaint, anonymously if need be, by contacting their area OSHA office or the agency's website at www.osha.gov. By law, workers are protected from recrimination for having filed a complaint, and cannot be fired, transferred, denied raises, or punished in any way for having exercised their right to complain. OSHA and MSDS Researcher Samuel Aaron Kaplan traces the origins of the Material Safety Data Sheets (MSDS) (http://www.ilpi.com/msds/) to Egyptian hieroglyphics, which gave users information about various chemicals and how to use them safely. Throughout history, alchemists and chemists have advised customers about safety precautions, and in the early part of the 20th century, the Public Health Service made chemical safety sheets available. By the 1940's the Manufacturing Chemists Association made information available on commodity chemicals, and in the 1950's Dow Chemical published an article describing their MSDS program. From an official US regulatory standpoint, the first requirements were adopted in the late 1960's in the maritime industry, which expanded to the manufacturing industry in 1983 when required by the Occupational Safety and Health Administration (OSHA). (http://www.osha.gov/) This was further expanded to cover all employers in 1987. MSDSs are now required in Europe, Canada, and Australia. Efforts to bring unified international standards are currently underway. The safety regulations and standards are extensive and complex. Business owners will need to be familiar with the standards that apply specifically to their enterprise and should consult their local OSHA branch when questions arise. Employees and consumers can now more easily obtain copies of these standards through public documents and through the Internet, and can also query OSHA directly.
135720-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_1.html 1/2  Editor's Note Lesson 37: Modems  37.1 What is a modem? A modem, short for modulator-demodulator, is an electronic device that converts the digital signals produced by a computer into specific frequencies for travel over telephone or cable television lines. This conversion is referred to as modulation. FM radio stations use a similar process to convert music into radio waves. After arriving at its destination, a modem receives the frequencies and demodulates the information, converting them back into digital code. Modem Communication After understanding how a modem modulates and demodulates data to enable computer communication, the next step is to understand how the computer sends and receives data. Most stand-alone modems communicate asynchronously. During asynchronous communication the sending device sends a start bit, alerting the receiving device to the fact that the next eight bits (one byte) are going to be a data packet followed by one stop bit to signal the end of a packet. Each eight-bit packet is the equivalent of one letter or number. Between each letter and number in every transmission, the modem sends/receives a start and stop bit. Asynchronous communication contrasts with synchronous communication, which uses a clock to synchronize data transfers, negating the need for the extra overhead of start and stop bits. Synchronous modems are used for high-end systems' communication needs. Regardless of whether a modem uses asynchronous or synchronous communication, modems are capable of sending and receiving data simultaneously. The ability to receive and send at a single time means modems are capable of full duplex transmissions. Full duplex mode is when the modem sends data bits out on one pair of wires while receiving data bits on another pair. Although modems can send and receive simultaneously, they may not necessarily send and receive at the same speed. For example, a 56Kbps modem can receive data at 56K, but can only send data at 33.6Kbps. Devices that can send and receive data—but not simultaneously—are known as half-duplex. Modem Form Factors There are two main modem form factors: internal and external. A modem connected directly to the motherboard inside a computer is called an internal modem. A modem that resides outside a computer and connects to the computer through a modem port is called an external modem. An internal modem plugs into a computer's expansion slot and draws power from a computer's power supply unit. An internal modem does not display a series of indicator lights. Instead, users rely on the internal modem's communications program for information regarding changing modem states. Residing outside a computer, external modems once connected to a computer by way of cable plugged in to a computer's serial port or USB port. This is no longer the case. Modern modems connect directly to the computer via an Ethernet cable. One advantage of external modems is that the status lights are located on its front face, giving the user easy access when troubleshooting. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_1.html 2/2
135820-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_2.html 1/3 Lesson 37: Modems  37.2 Types of Modems Today, there are a number of different types of modems, each matching up with a specific type of Internet connection (such as dial-up, cable, DSL, etc.). Although not all of these types of connections require conversion between analog and digital form, the collection of devices used to connect a PC to the Internet are collectively referred to as "modems." Below is a summary of uses and advantages of three common modem types: Broadband Modems A broadband modem is a type of digital modem used with high-speed DSL or cable Internet service. A cable modem is used to connect a computer to cable TV services that provide Internet access, while DSL modems connect to residential public telephone service. While broadband modems use complex waveforms to carry digital, rather than analog data, they are still classified as modems. Wireless Modems Modems using mobile telephone services are called wireless modems (also known as mobile or cellular modems). Wireless modems provide internet access while on the move, or when a connection to a wireless access point is not always reliable. Connect cards, slide into a PCMCIA/PC or ExpressCard slot whereas USB wireless modems use USB ports. Wireless modems may also be embedded inside a laptop or a cellular router. Most cellular routers provide multiple connections while wireless modems support one connection. Just like mobile phones, wireless modems can be sim locked for particular service providers. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_2.html 2/3  Editor's Note In other parts of the world, a USB mobile broadband modem may also be referred to as a dongle. Dial-up A dial-up modem, still used by some home users to connect to the Internet, are capable of download speed of up to 56 kbit/s. Popular in the late 1990s, their use has sharply declined in most developed countries as broadband technologies have been implemented with DSL and cable Internet, along with mobile data services such as 4G. The Hayes Command Set The vast majority of dial-up modems use the Hayes command set in numerous variations. A standardized set of instructions to control modems, the Hayes command set was adopted by other manufacturers to ensure their product was compatible with other computer systems. The term "Hayes compatible" is synonymous with the ability to support AT (Attention) commands. AT commands send instructions to the modem. However, applications that require a modem are able to send AT commands automatically. Therefore, AT commands are seldom used by computer users. Technicians, however, need to be familiar with helpful, troubleshooting AT commands. If your computer is in terminal or HyperTerminal mode and you have a modem installed, you can use AT commands to access, diagnose, or manipulate your modem. AT Stands for attention. It must be typed in before any command. Alone, the command is used to check that a modem is turned on. The modem should respond with OK. ATD Takes the phone off of the hook and dials the number included with the modem command (e.g., ATDT for touchtone dialing and ADTP for pulse dialing). ATDL Dials the last number ATH Used to hang up the modem ATI Used to get information (e.g., use ATM0 to get the product code and ATI4 for the current modem settings) ATM0 Turns speaker off ATM1 Turns speaker on ATZ Used to reset the modem General Modem Commands 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_2.html 3/3
135920-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_3.html 1/5 Lesson 37: Modems  37.3 Connection Types As the demand for faster, more efficient internet connections increase, so do the number of options developed to meet these needs. Following is a brief description of some common connectivity choices available today: Cable Cable Internet access provides increased bandwidth and dramatically increases the speed between the user's computer and ISP. Cable modems provide connectivity using a broadband Ethernet access method, resulting in constant online service running at approximately 30Mbps, although speeds can vary. Ethernet is a shared medium; therefore, access speed will vary depending on how many customers are sharing the bandwidth. Bandwidth is a measure of how much data can be transferred along a particular pathway. Like a highway, the more lanes that exist, the more traffic that can proceed, at a faster pace through those lanes. When the highway traffic bogs down with a lot of cars, everyone slows down. DSL DSL technology caters to two types of uses: asymmetric DSL (ADSL) is for Internet access where quick downstream is required, but slow upstream is acceptable. Symmetric DSL (SDSL, HDSL, etc.) is designed for shorter distance connections that require high speed downstream and upstream. Essentially DSL is a home- or office-installed digital phone line that allows a computer to bypass analog transmissions. DSL speeds depend on the distance between a customer and a telephone central office. With greatly increased digital service, this is widely available today. A DSL will provide a constant connection. Leased Line Most commonly used by businesses for their faster data transfer rates and cost-effective Internet access, a leased line connects two locations for private voice and data communications. Like cable, leased lines offer a permanent, available anytime connection. Two common leased lines are T-1 and T-3. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_3.html 2/5 A T-1 connection operates at 1.55 megabits per second (Mbps). A T-3 is the equivalent of 30 T-1 lines, offering 45Mbps transfer rates. Both T-1 and T-3 are broadband digital network connections and are intended for business use or environments where many users will need to access the Internet simultaneously. Dial-Up Dial-up is the oldest form of internet connection, capable only of 56Kbps or lower. It uses your phone line to connect to your Internet Service Provider (ISP). Also, if you only have one phone line you won’t be able to access the internet while talking on the phone. Dial-up modems are much slower compared to cable and DSL and are rarely used in most developed areas. ISDN An integrated services digital network (ISDN) is an international telecommunications standard for the transmission of voice, video, and data over digital lines, and runs at 64Kbps. Telephone companies often use a single 64Kbps channel for digitized, two-way voice transmissions. ISDN service is available in most parts of the U.S. ISDN connectors are not considered actual modems. Wireless Wireless communication is a radio transmitted connection between sender and receiver that take place via airwaves. Various wireless transmissions include infrared line of sight, cellular, microwave, satellite, packet radio and spread spectrum. Multiparty teleconferencing, personal digital assistants, distributed work sessions and electronics newspapers are a few applications for wireless networks. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_3.html 3/5 Wireless is the freedom of mobility without losing a connection. Other benefits include greater range and the fact that no cables are required. Fiber Optics Fiber optics offers outstanding speed and bandwidth. However, it is expensive and typically used by businesses due to the costs. Fiber to the Home (FTTH) provides high-speed connectivity to homes such as Verizon’s FiOS, which provides singlemode optical fiber to the home. FiOS bundles Internet access with phone and television services. Cellular While connecting to the Internet using WiFi is the easiest method for mobile computing, connecting with a cell phone is possible under other conditions. Most cell phone companies allow users to access the Internet through their laptops/notebooks. Digital mode phone: a dual mode phone operates on both the 1900 MHz and 800 MHz digital networks while a trimode phone can additionally operate on the 800 MHz analog network. Data port – most modern cell phones have a port that allows you to connect to various Internet connecting devices Special cable or connecting devices—including any software that may be required to connect to your laptop Proper service plan—one that includes data services Internet Service Provider (ISP) 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_3.html 4/5 Developed in the early 1980s, the older Advanced Mobile Phone System (AMPS) uses analog technology, so it does not offer Web browsing or e-mail services. Neither does Narrowband Advanced Mobile Phone System (NAMPS) since it operates only on the 800 MHz band. Second generation (2G) cell phones launched in 1991. These digital devices use one of three technologies: Frequency division multiple access (FDMA) – too inefficient to be adopted Time division multiple access (TDMA) – uses channels and operates digitally in either the 1900 or 800 MHz frequencies Code division multiple access (CDMA) – a form of spread spectrum technology TDMA is the access method that was adopted by the Telecommunications Industry Association (TIA) and Electronics Industry Alliance (EIA). Fastest download speeds for second generation cell phones is up to 144Kbp. The new Millennium brought great improvements. Third generation (3G) cell phones are significantly faster and more efficient; thus, they are much better for downloading from the Internet. With transfer speeds approaching 3 Mbps third generation phones can perform various broadband applications—streaming audio/video from the Web, handing e-mails with attachments, video conferencing, etc. Common technologies used by third generation cell phones are: CDMA2000 Wideband Code Division Multiple Access (WCDMA) Time-division Synchronous Code-division Multiple Access (TD-SCDMA) The recent release of 4th generation (4G) cell phones provides transfer speeds of up to 100 Mbit/s. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_3.html 5/5 WiMAX WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communications standard that delivers high-speed broadband internet access over a wireless connection. Unlike other wireless technology, WiMAX doesn’t require a direct line of sight between the source and its endpoint. Providing a shared data rate of up to 70Mbps, WiMAX is considered to be the ultimate solution to deliver broadband to locations where wired connections would prove to be too difficult or costly. Satellite Internet over Satellite (also referred to as IoS) uses a satellite to handle data transmissions. Unlike cable or DSL where speed fluctuations can and will occur, satellite internet allows for smoother connections. Combined with an outdoor antenna and subscription to a satellite service, a satellite modem is one of the fastest modem options available and remains a top choice for users in remote locations where conventional forms of connectivity are not available. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_4.html 1/2 Lesson 37: Modems  37.4 Modem Components Since the majority of users today access their Internet via a cable modem, it is important to have a basic understanding of common components featured on a standard cable modem. Internal Components Internal components of a typical cable modem contain a tuner, demodulator, modulator, MAC device, and microprocessor. The tuners job is to separate the Internet channel from normal television channels and pass the signal to the demodulator. The Demodulator and Modulator control the duplex of information in the cable modem. The demodulator takes the signal from the tuner and converts it from analog to digital, checks the signal for any errors, then arranges and corrects them. Upstream data is handled in the modulator where information is moved in reverse order. The data is first checked for errors and then converted from digital to analog for outbound transmission. Every networking component receives its own unique MAC address and the cable modem is no different. The MAC device in a cable modem acts to manage the hardware and software of network protocols. If more complex tasks are necessary such as receiving user input, they are sometimes carried out by a microprocessor. External Modem Lights External modems are equipped with indicator lights that show what is happening during the communication process. Knowing what each light means helps to troubleshoot modem problems and is important to understanding a modem's status. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson37/lesson37_4.html 2/2 STANDBY BUTTON – Offers added Internet Security. When pressed, interrupts Internet connection until pressed again. POWER LED – Flashes when startup is being performed. A solid light indicates modem is turned on. RECEIVE LED – Flashes when scanning for a receive channel connection. A solid light indicates the connection is acquired. SEND LED – Flashes when scanning for a sends channel connection. A solid light indicates the connection is acquired. ONLINE LED – Flashes when scanning for a network connection. A solid light indicates the network connection is acquired. PC/ACTIVITY – Flashes when transmitting or receiving data. No light indicates the modem is not transmitting or receiving data. STANDBY LED – A solid light indicates the Internet service is blocked because the standby button on top of the modem was pressed. If this light is on, all other lights are automatically turned off.
136020-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_1.html 1/1  Editor's Note Lesson 38: NICs and Network Hardware  38.1 Network Interface Controller (NIC) In the most basic terms, a Network Interface Controller (NIC) is a hardware component that performs all the functions required for a computer to communicate on a network. Also referred to as a Network Interface Card, older computers used a separate peripheral expansion card that plugged into a computer's motherboard and interfaced with a network cable. The low cost and ubiquitous nature of the Ethernet standard led to most computers now having the network interface built directly into the motherboard. Acting as a data mediator, a NIC controls the data exchange between a computer and a network. A NIC also provides services at the data link and physical levels of the network, known as the access method, or Open System Interconnect (OSI) layers 1 and 2. Understanding the OSI model requires understanding its layered approach to networking. Each OSI layer handles a specific portion of the communications process. Layering makes it possible for network hardware and software to work together and eases troubleshooting. OSI is a model that helps to explain the process of sending and receiving data between devices. There are 7 layers with various protocols and devices that implement the functions of that layer.
136120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_2.html 1/1 Lesson 38: NICs and Network Hardware  38.2 How NICs Work A NIC receives data slated for transmission from a computer’s motherboard. That data is placed into a tiny amount of RAM known as a "buffer." The data travels from the buffer into a chip that calculates values for the data and provides address information. The NIC then converts serial data bits for transmission over a specific media. For example, fiber optic transmissions require infrared, LED-emitted data. Twisted-pair cable transmissions require data logic in the form of 5-volt bursts. The circuitry a NIC uses for these conversions is called a transceiver. Transceivers can be external devices attached to an Ethernet adapter or exist internally on a network interface card. Some NICs feature more than one transceiver for multiple data transmission and media choices. Collisions When multiple adapters on a LAN try to transmit data over one wire, at the same time, interference between the signals occurs, resulting in garbled data. This occurrence is called a collision. Adapters transmit data while "listening" to media lines, and check if the transmitted data matches the data being sent over the outgoing line. When data matches, things are working properly. When a remote adapter interrupts the signal by inappropriately sending its own data, the data on the outgoing line will no longer match. When data is unmatched, a NIC ceases sending data, and sends instead a signal to the computer to discard incoming information. This "disregard" signal indicates a collision has occurred. After a small, random amount of time, the NIC will reattempt to send collided data. If the lines are clear, the transmission occurs successfully, but if a collision occurs again, then a random amount of time is spent waiting again until more communications are attempted. Both Token Ring and Ethernet LANs employ strategies to either avoid or detect collisions. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_3.html 1/4  Editor's Note Lesson 38: NICs and Network Hardware  38.3 Choosing a NIC Today, most new computers have either Ethernet capabilities integrated into the motherboard, or use an inexpensive dedicated Ethernet chip connected using the PCI or PCI Express bus. A separate expansion card is generally no longer needed. Some older systems, however, may require a Network Interface Card if not already built into the motherboard. In that case, the following information may prove helpful in selecting the NIC that best suits your needs. Important variants to consider when selecting a NIC are the following: Sending and Controlling Data To facilitate data communication between a PC and server, NIC cards must be compatible in several key areas. These areas include: Maximum size of data frames Amount of data sent before establishing confirmation Time allotted between transmissions Time required before sending confirmation How much data a card can hold Transmission speeds NIC cards must agree with each other, and be of like types before data transmissions can be successful. When cards disagree or are different, communication doesn't take place. Configuration Configuring a NIC includes details of a manufacturer’s hardware address, IRQ address, a base input/output (I/O) port address, and memory address. In some cases, dynamic memory address channels improve performance. EEPROM (Electrically Erasable Programmable Read Only Memory) on a NIC stores its IRQ and I/O address settings and its MAC address. EEPROM can be erased and reprogrammed when a higher-than-normal electrical voltage is applied. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_3.html 2/4  Editor's Note Each NIC card requires its own hardware address called a Media Access Control (MAC) address. MAC addresses work at the Data Link Layer (2nd layer) of the OSI model as a way of identifying and differentiating between network interfaces. MAC addresses are a lot like human fingerprints in that no two sets of prints are identical. Due to their unique nature, these fingerprints (or MAC addresses) can be used to identify a specific person (or networked device). Because MAC addresses serve as unique identifiers, no two NICs have the same MAC address. Though held on EEPROM, a NIC's MAC address is not configurable. It is permanently set by the manufacturer. Jumpers or software, however, can be used to change a NIC's IRQ and I/O address settings. The need for unique hardware addresses is why the Institute of Electrical and Electronics Engineers (IEEE) committee established a standard for hardware addresses, and provides NIC manufacturers with media access control addresses. Assigned to and adopted by each NIC card, media access control addresses fulfill identification purposes over a network. Configuring a NIC is similar to configuring any other expansion card. Generally, a NIC requires a unique IRQ (interrupt request) channel, input/output (I/O) address, and even a DMA channel. Also, Token Ring cards commonly feature two memory addresses that should be excluded within reserved memory if they are to work correctly. Test Your Knowledge How does EEPROM differ from EPROM? A. EEPROM cannot be reprogrammed B. EPROM is not used for memory C. EPROM must be removed from the computer to be modified D. EEPROM must be removed from the computer to be modified Drivers 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_3.html 3/4 A driver is a specialized software program routine that links a peripheral device to the operating system. Using the correct device drivers is essential for a NIC to function properly. It is important to keep drivers up to date because manufacturers regularly fix problems and programming bugs with new driver software. Compatibility Be certain to select a NIC compatible with your computer’s bus type. If your computer features both PCI and PCIe, remember that PCIe cards are faster than PCI cards. Choosing the correct NIC becomes crucial in the performance of a server where data bottlenecking can occur. Performance Perhaps the most important aspect of selecting a NIC is optimizing network performance and minimizing data transfer time. Three ways to increase performance include assigning it a DMA channel, using a shared memory adapter, or allowing bus mastering. Portability A wireless NIC is used if a desktop computer needs to be easily moved, or you need to move around with a laptop but still want to connect to a network and the Internet. Rather than a wire-based network such as Ethernet, a WNIC connects via radio-based computer networks. Common wireless standards include 802.11a, 802.11b, 802.11g and 802.11n. The 802.11a standard operates in the 5 GHz frequency band, can transfer data at up to 54 Mbps, and has a range of 50 – 150 feet. 802.11b operates in the 2.4 GHz frequency band, can transfer data at up to 11 Mbps and has a range of 115 – 460 feet. 802.11g operates in the 2.4 GHz frequency band, can transfer data at up to 54 Mbps and has a range of 125 – 460 feet. 802.11n can transfer data at up to 600 Mbps and has a range of 230 – 820 feet. 802.11n can operate on both the 2.4 GHz and less common 5 GHz bands 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_3.html 4/4 A wireless access point (WAP) is required to connect a wireless NIC to a wired network, to other wireless devices, and to the Internet. An access point is a receiver and transmitter of wireless radio signals.
136220-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 1/7  Editor's Note Lesson 38: NICs and Network Hardware  38.4 Network Media (Cabling) A computer network, considered one large electronic entity, is actually made up of hundreds of smaller components helping each other to correctly distribute information. Individual, unique network systems share many essentials common to all computer networks. Data transfer media cables are one universal network element. Network hardware is another. When developing a network, it is important to consider where to place all the network cabling. One place is the plenum. It is located between the real and the dropped ceilings (or in false floors) that is often used for air circulation of heating, ventilation, and air-conditioning (HVAC). In order to comply with applicable environmental, fire protection regulations, and local building codes, plenum cabling has a fire-retardant coating (usually Teflon) then covered in PVC (polyvinyl chloride) or FEP (fluorinated ethylene polymer) since it produces a minimum of smoke and is non-toxic at high temperatures. Polyvinyl chloride (PVC) is the outer insulation that covers most network cables. PVC emits a poisonous gas when burned. Connecting a network's various devices requires media to carry data. Media can include wires, cables, and microwaves. Currently, cables are the most common and widely used medium for connecting networks. However, fiber networks are becoming more and more popular every day. Each form of media has its own distinct characteristics, including: price, feature limitations, speed, and ease of installation. It is important to consider each factor when creating and installing a network. There are four main types of network cables. 1. Shielded twisted-pair wire 2. Unshielded twisted-pair wire 3. Coaxial cable 4. Fiber optic cable Twisted-pair cable is a thin-diameter wire commonly used for telephone and network cabling, and comes in two styles: shielded twisted-pair cabling (STP) and unshielded twisted-pair cabling (UTP). The twists in twisted pair wires offer the advantage of reduced interference on the line. Reduced interference allows the wires to extend farther than if they were not twisted. STP and UTP cabling can extend a maximum of 100 meters from node to node including all patch panels and patch cables. Shielded Twisted-Pair Cable Shielded twisted pair cable is telephone wire covered by woven copper or aluminum mesh that shields the wires from each other and from outside interference. Shielding and twisting help protect wires from Electromagnetic Interference (EMI). Traditionally, shielded twisted-pair cabling has been associated with AppleTalk and Token Ring networks, or networks that contain excessive electrical noise (Electromagnetic Interference - EMI). Another variation is the Screened Twisted Pair (ScTP) that is useful for networks with extremely high levels of EMI. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 2/7 STP (Shielded Twisted Pair) and ScTP (Screened Twisted Pair) Unshielded Twisted-Pair Cable (10BaseT, 100BaseT, 1000BaseT, and 10GBaseT) Unshielded Twisted Pair (UTP) cabling is popular in many networks because it is easy to install. UTP cabling is commonly connected to a network with RJ-11 or RJ-45 connectors. RJ-11 - Registered jack-11 (RJ-11) is the connector most people are familiar with because it is used for telephones. The RJ-11 consists of only four wires connected to the plastic ends. Both ends are the same, as one is hooked into the telephone and the other end goes into the modem. RJ-11 connectors are also used to connect some types of local-area-networks, although RJ-45 connectors are more common. RJ-45 - The registered jack-45 (RJ-45) looks a lot like the RJ-11. However, beneath its plastic connector, the RJ-45 houses 8 wires (4 unshielded twisted pairs), making the connector a little larger than the RJ-11. RJ-45 are used to connect a system in either a token-ring or Ethernet LAN. UTP features four separate twisted pairs of color-coded wires. Additionally, UTP’s cabling size is similar to telephone cable and can be installed easily alongside existing telephone cables. UTP (Unshielded Twisted Pair) There are five UTP standards, each category offering greater benefits than its predecessor. These benefits are summarized in the table below. Ethernet supports network segments up to 100m over UTP. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 3/7  Editor's Note Category 1* voice only Category 2* 4Mbps Category 3 16Mbps Category 4 20Mbps Category 5 100Mbps Category 5e An extension to the Cat5 standard allowing 1000Mbps over Cat5 cable. Category 6 1000Mbps, better designed for Gigabit Ethernet than Cat5e. Category 7 1000Mbps to 10Gbps *Categories 1 and 2 are not used for computer networks. CAT6 Category 6 (CAT6) is used in 10GBaseT networks and contains four twisted pairs of copper wire. Using a separator, CAT6 twisted pair separates each of the four pairs of wires from one another, thereby reducing crosstalk. CAT6 specifies cable lengths up to 100 meters using CAT6a. In addition, CAT5 transmits data at speed up to 10 Gbps and has a minimum of 250 MHz of bandwidth. CAT 7 Category 7 (CAT7) network cabling is utilized in 1000Base-T as well as 10GBase-T networks. Along with its own twisted wire pairs fully shielded, CAT 7 offers higher performance in comparison to CAT 5 and CA6, allowing performance of up to 600 MHz (1000 MHz for the Cat-7a, or Augmented Category 7 standard) and can be utilized up to a maximum length of 100 meters. CAT 7 is more expensive in comparison to CAT 5 and CAT 6, however it have a 15-years lifespan which is longer than both CAT5e and CAT 6. 10BaseT Ethernet requires Category (CAT) 3 UTP cable or higher. 100BaseTX, a 100Mbps Fast-Ethernet technology, requires CAT 5 or higher. Coaxial Cable In general, coaxial cable (co-ax) is high-capacity cable used in data communications, network connections, and video equipment. Co-ax cable was the first type of computer network cable and helped to form the foundation of original Ethernet standards. UTP Category Standards Maximum Data Transfer Rate 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 4/7 Coaxial cable's woven mesh acts as an electrical ground while helping protect the internal wire from electrical interference. There are two important network standards that uses coaxial cable: 10Base2-ThinNet and 10Base5-ThickNet. 1. 10Base2 (ThinNet) - Cable for a 10Base2 network uses an insulated copper conductor, surrounded by braided copper shielding, and wrapped in a plastic layer. ThinNet is capable of 10Mbps data transfers over distances up to 607 ft. (185 meters.) Shaped like the letter T, BNC is a connector type for 10Base2 or Thin-Net networks. Usually BNC connectors connect Ethernet networks running on coaxial cable. However, BNCs can also be used to connect some monitor types to video cards, enabling a higher quality signals. 2. 10Base5 (ThickNet) - Like its 10Base2 counterpart, 10Base5 conforms to10Mbps data transfer rates. Unlike 10Base2, ThickNet signals can travel up to 1640.4 ft. (500 meters.) without a repeater. The main difference between the two cable types is their copper core: 10Base2 uses a thin braided copper shielding; 10Base5 uses a thicker, solid copper core to transmit data. A series of standard coaxial cables that were initially specified for military use are identified with an RG designation. RG stands for Radio Guide; the U designation stands for Universal. The number associated with a particular RG cord is arbitrary and has no bearing on the quality of a cable, so an RG-59 is not necessarily better than a RG-6 cable. Two commonly used coaxial cable types for video applications are RG6/U and RG59/U. 1. RG6/U - This thick coax cable is recommended for distributing signals from cable TVs or, satellite dishes. RG6 cables construction provides better shielding then RG59 cables. 2. RG59/U - This is a Thinnet coax cable specifically used for broadband transmission in cable television service. This CATV (community antenna television) cable carries a 75ohm impedance rating. RG-59U is utilized to generate low-power video connections. RG-6 can support digital signals and can run longer distances than RG-59. Due to its high-frequency power losses, the RG-59 cable cannot be used over long distances. The diameter of the cable of RG59 and RG6 differ in that standard RG59 coax contain a 20 AWG copper center conductor while RG6 coax contain a larger 18 AWG copper center conductor, allowing higher bandwidth and longer distance capability. RG59 is used for analog CCTV or baseband video applications. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 5/7 RG6 Dual or Quad Shield is made using foil shields and braided aluminum shields therefore it should not be used for baseband applications, such as plasma TV’s, component video, and video projectors. The braiding on the RG6 Dual shield and the RG6 Quad shield does not work well with baseband applications because it does provide enough coverage. RG59 shouldn’t be used for satellite feeds or cable feeds because it does not contain a foil shield. It is better to used RG6 shielding than RG59 to maintain Gigahertz level inside of the center conductor. RG6 has become the standard for broadband CATV and satellite systems because it has a far more superior design for maintaining the signals levels inside the center conductor. RG59 comes with a copper braid while RG6 contain an aluminum braid and an aluminum shield. RG59 can generally be utilized for video frequencies, while RG6 can be utilized for any rapid frequencies. Fiber Optic Cable (10BaseF, 100BaseF, 1000BaseF, and 10GBaseF) Fiber optics, the first version known as 10BaseF, became popular in the mid-1980s when long-distance carriers created nationwide fiber optic networks to carry digital voice conversations. By definition, optics means "visual," and "fiber" indicates a threadlike component or string. The fibers are about as thick as a strand of human hair. 10BaseF supported data transfer rates of 10Mbps. Networks based off of fiber optics today can reach speeds of 10000Mbps, or 10Gbps. There are a variety of cable types: 10GBase-SR, 10GBase-LRM, 10GBase-LR, 10GBase-ER, 10GBase-ZR, and 10GBase-LX4. Fiber optics deliver light signals through glass or plastic fibers, making it impervious to EMI and cross-talk. Additionally, fiber optics data lines are far more efficient and secure than other network transmission media, but cost more than previously discussed media. Fiber optic cables are classified by their core/cladding size and mode (single mode or multimode). Single-mode cables, commonly used in conjunction with laser signaling, feature a single light path and work by reflection. Single-mode is generally used for long distance telephone communication. Multimode fibers use multiple light paths that work by refraction and are most often used in LAN applications. The size and purity of the cable core elements determine how much light can be transmitted. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 6/7 There are multiple fiber connectors on the market, but ST (Strait Tip), SC (Subscriber Connector), and LC (Little Connector) are currently the most common types of connectors available today. ST Connector - One reason the ST connector are popular is its ease of use, making connections and disconnections fairly easy (only a quarter turn) while using a BNC attachment. SC Connector - The SC connector, sometimes referred to as a square connector or standard connector, is a snapin connector that utilizes a push-pull mechanism for connection. SC connectors will last for about 1,000 connections and work with either single or multi-mode optical fibers. An advantage of SC connectors is to join several plugs together to form a multi-position connector. This is especially advantageous in building a two position or duplex connectors allowing information to be sent and received simultaneously. Both ST and SC connectors have the same ferrule 2.5 mm size, which allows them to be easily mixed and matched to each other by using an adapter. LC Connector - LC is another popular connector for fiber-optic networks. LC is a 1.25 mm ferrule, half the size of ST and SC. Similar to SC connectors, LC connectors use a snap-in connector that hooks on with a simple pushpull motion. LC is used for high-density connections, SFP transceivers and XFP transceivers. Plenum Cable In building construction, a plenum is a separate space provided for air circulation, heating, ventilation and air conditioning. A plenum may be located under a raised floor, in a ceiling or in a wall. The plenum space is often used to house communication cables. Because ordinary cables can produce toxic gases when burned, plenum-rated cabling is required for plenum areas. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_4.html 7/7 Plenum cables are often made of Teflon and are more expensive than ordinary cabling. In the event of fire, its outer material is more resistant to flames and produces less smoke than ordinary cabling when burning. Both twisted-pair and coaxial cable are available in plenum varieties.
136320-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_5.html 1/5 Lesson 38: NICs and Network Hardware  38.5 Common Network Hardware Routers A router determines how data packets are routed and transferred between two networks. Routers create network address tables based on a node's IP address and determine optimal destination routes for each address. Routers are the devices responsible for getting information from one side of the world to the other when data is sent across the Internet. The massive collections of networks on the Internet mean that more than one path may be available to get data from point A to point B. Routers guide the data across these multiple paths. Bridges A bridge breaks a LAN into multiple segments, also called collision domains. Segmenting a network with bridges allows the bridges to filter out network packets that are not destined for certain parts of a network. A good time to segment a network with a bridge is when many computers on the same network cables cause collisions. The bridge helps manage the collisions, increasing the efficiency of a network. A bridge can also regenerate signals, allowing for longer network distances. Bridges also allow translation between different types of cabling. For example, a bridge could connect a segment using 10base2 coaxial cable to a segment using 10baseT unshielded twisted pair. Switches A switch is similar to a bridge but with multiple ports. Like a bridge, a switch also breaks a LAN into multiple collision domains, which increases network efficiency. In order to forward data, a switch creates a content addressable memory (CAM) table which matches a computer's MAC address with its corresponding port on the switch. Due to the CAM table, switches only forward data to the destination computer, which conserves bandwidth and increases network efficiency. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_5.html 2/5 Gateways Networks communicate within the framework of protocols (rules) that ensure data is transmitted in a reliable and consistent manner. When different types of networks try to communicate with each other, they require a gateway. A gateway is a liaison between protocols, allowing you to access networks that use different protocols to communicate. For example, a gateway enables communication between a TCP/IP and IPX network, in addition to enabling access to applications stored on other networks that use different protocols. A gateway is more expensive than a router and works more slowly. Repeaters Repeaters are necessary and integral network devices that facilitate data transfer of over distances longer than cable specifications allow. Cables have maximum length specifications because at certain distances the original signal sent by a computer dissipates. The dissipation is known as attenuation. Repeaters work one of two ways. One method is by simply amplifying the signal (like turning up the volume on a stereo), which amplifies both the data and any noise on the cable. A better and more expensive repeater actually copies and regenerates the data signal while filtering out the noise. With either amplification or regeneration, the end result is the same: the signal can continue to travel through extended cable segments toward a network hub or receiving node. Hubs A hub is a central connecting device that provides a central location where all communications lines join together. The essence of a hub's job is to connect data lines between all the computers on a LAN. Active hubs also act like repeaters by amplifying the signal. A hub differs from a switch in that it forwards received data out of all of its ports, whereas a switch uses its CAM table to only send data out of the port of the destination computer. This reduces a hub's efficiency and lowers available bandwidth.. Unless you are connecting five or fewer computers, hubs are not the equipment of choice. Switches would be more efficient and economical, especially considering recent reduction in their price. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_5.html 3/5 Access Points An Access Point (AP) is a vital component for a WLAN. It is needed so that wireless devices can communicate with the network. An AP can also communicate with another AP using the wired network. This saves the wireless bandwidth. A single AP can be referred to as a Basic Service Set (BSS). If more than one AP is connected to a wired segment, the topology can be called an Extended Service Set (ESS). The wired network is called the distribution system. Access points operate in one of the following modes: 1. Root Mode – This is the default mode of operation. In root mode, the AP is connected to the wired foundation of a network (usually the Ethernet) as shown below. An AP typically operates in root mode. If it also supports one or both of the other modes, the default will likely be root mode. Klik om Adobe Flash Player in te schakelen A Wireless Access Point (AP) in Root Mode 2. Bridge Mode – An AP operating in bridge mode essentially becomes a wireless bridge. Bridges are used to link together two or more wired segments. They may be located in different parts of the same building or in separate buildings. The graphic below shows a network using the AP as a bridge and not actual wireless bridges. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_5.html 4/5 Klik om Adobe Flash Player in te schakelen A Wireless Access Point (AP) in Bridge Mode 3. Repeater Mode – In repeater mode, an AP provides a wireless upshot link into the wired network. The AP repeater connects to clients as an access point. It connects to a root mode AP, as a client. This is shown below. There must be at least a 50% overlap of the cells involved. The AP repeater exchanges with both clients and with the upstream AP. Throughput on this wireless section is reduced. For these reasons, this configuration is recommended only if absolutely necessary. Klik om Adobe Flash Player in te schakelen A Wireless Access Point (AP) in Repeater Mode Common Access Point Options An AP is a portal, from architecture specified in the IEEE 802.11 for LANs to the 802.3 specifications for Ethernet or other network type. Available hardware and software options vary by manufacturer and model. Following are the options most frequently available on an AP: Antennas – A detachable antenna provides flexibility to select the best antenna for the AP location and usage. For example, cable can be used to connect an AP mounted indoors to an antenna mounted outdoors. Some APs are shipped with diversity antennas. This means that input from multiple antennas is sampled and the input signal with the best reception is used. Illustrated below are some of the available detachable antenna types, as well as an AP with diversity antennas. Antennas will be discussed in more detail in a later chapter. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson38/lesson38_5.html 5/5 Klik om Adobe Flash Player in te schakelen Antennas Filtering – MAC address or protocol filtering can provide a basic level of security by screening out devices that are not in a defined MAC or protocol filter list. An example of a protocol filter would be an HTTP filter, which would only allow web browsing from the wireless LAN. Modular Radio Cards – A single PCMCIA slot allows upgrading by swapping the radio card. With multiple slots, an access point could perform both the AP function and the bridging function. It could also serve as multiple, colocated APs. In both cases, non-overlapping channels would be used. Variable Output Power – This option allows the administrator to control the power. Increasing the power allows clients to move further away and still remain connected. Lowering the power can help security, by limiting the size of the cells. Without variable output power, amplifiers, attenuators, long cables, or high-gain antennas might need to be implemented. When adjusting power levels in any of these ways, it is important to always be aware of FCC guidelines. Wired Connection Types – Almost all APs support Ethernet/802.3 connections, most frequently 10/100 802.3. Some APs will support other choices, such as 802.3 over fiber or Token Ring.
136420-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_1.html 1/1 Lesson 39: Networking  39.1 What is Networking? When people socialize, they exchange information, contacts, ideas and resources. When computers network, they also engage in similar "conversational" activities. Networking occurs whenever two or more computers connect to share data and resources. Although some computer networks can be extremely complex, the basic principle is simple, connecting to share resources. If you use computers in a work or school setting, you are likely in a common networking situation. Sharing resources like printers and Internet connections—by way of a network—is generally more economical than maintaining several independent printers and connecting each computer to the Internet directly. Likewise, collaborative file sharing and e-mail makes coordination of many departments easier.
136520-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_2.html 1/3 Lesson 39: Networking  39.2 Network Types The four basic [data] network types are: 1. Local Area Networks (LAN) 2. Metropolitan Area Networks (MAN) 3. Wide Area Networks (WAN) 4. Personal Area Networks (PAN) The type of network chosen depends on the following variables, which include the number of potential computers and end users, security considerations, financial resources, and the geographical and physical location of the networked organization. Local Area Network (LAN) The LAN, an evolution from "stand alone" computers, is the least complicated type of network. A LAN connects computers and network devices within office buildings. A LAN can also connect a small, local group of buildings. LANs provide groups of individuals with access to resources such as printers, files, and databases. Allowing many users to share resources, commonly accessed files and databases, LANs offer small businesses economy and convenience. Metropolitan Area Network (MAN) A MAN is a communications network similar to a LAN that covers a much larger geographic area, linking servers across a city or town. MANs can be thought of as a group of interconnected LANs. While MANs are much bigger than LANs, they are much smaller than WANs (Wide Area Networks). At its maximum, a MAN can cover a single metropolitan area. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_2.html 2/3 Wide Area Network (WAN) A Wide Area Network (WAN) connects multiple LANs over long distances, including states, countries and continents. WANs are the largest type of network, connecting both networked and individual computers throughout the world. Imagine a WAN as "interconnecting" smaller networks, worldwide, to achieve greater, more efficient information sharing. The largest WAN is the Internet. Asynchronous Transfer Mode (ATM) is a WAN technology that has gained popularity because of its ultra-fast transfer speeds. ATM offers a solution to limited bandwidth by sending data packets of a consistent and predetermined size. ATM can transfer data at up 622Mbps. Personal Area Network (PAN) A personal area network (PAN) connects devices, which are dedicated to a single host. Devices such as a printer, smartphone and tablet are within the range of an individual person and are typically connected with Bluetooth technology. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_2.html 3/3
136620-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_3.html 1/3 Lesson 39: Networking  39.3 Network Topologies Networking topology refers to the network's physical layout. A network's topology is made up of a network's connecting devices. The topology's structure describes the way a network's hardware is connected. Network topologies are typically classified into one the following types: bus, ring, star, mesh, or hybrid. Bus A bus network is a basic topology in which all computers on a network are connected by a single length of cabling with a terminator at each end. When a bus network computer sends a signal, every computer on the cable receives the signal. However, only the intended computer—the addressee—accepts the data. Every other computer on a network disregards the data. Since only one bus network computer can send a message at a time, a network's speed decreases as the number of networked computers increase, due to increased collisions and contention for time on the cable. Another bus topography drawback is when the bus cable breaks, all network communications are disrupted. A bus topology is best suited for a low traffic network with only a few computers, or for a high-speed backbone between multiple networks. Star A star topology links all the computers on a network to a central location where they are connected together by a hub or switch. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_3.html 2/3 The star topology, much easier to wire and maintain than a bus topology, is more widely used. Another benefit of a star topology is that failure of one computer will not affect the other computers in the arrangement. "Intelligent" hubs can monitor a network and report errors and problems in the star arrangement. Failure of the central hub or switch will disrupt communications to computers and resources that utilize the hub or switch. Ring A ring topology places all the computers in a circle or ring. Data travels around the computer ring in a single direction. Each computer in a ring network acts as a repeater, passing on information intended for other computers. As data is passed along in the ring, a token is also passed. This token signals the computer receiving the token to send any data waiting to be transmitted. Without the token, a computer cannot transmit data. This token-passing protocol allows only the computer with the token to transmit. Like the bus topology, a ring topology is fairly simple to install and configure, and doesn’t require a lot of hardware. The two most common ring topologies are the Token Ring and fiber distributed digital networks (FDDI). Ring topology is named after the ring-shaped configuration of the network's computers. Mesh 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_3.html 3/3 A mesh topology connects every computer on the network to every other computer. A mesh topology requires significantly more cabling than other types of topologies, and mesh is by far the most complex network to install and configure. Thanks to complex and costly installation, a mesh network will continue to function despite individual failures. Mesh topologies are extremely fault tolerant because each computer has multiple connection paths to the other computers on the network. Hybrid A hybrid topology is created when two or more basic network topologies are combined. In such a case, the hybrid topology no longer exhibits solely the qualities of either topology. Thus, two tree networks combined would NOT be a hybrid since they would form a new tree topology. On the other hand, joining two star topologies together would form a hybrid topology.
136720-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_4.html 1/4  Editor's Note  Editor's Note Lesson 39: Networking  39.4 Network Architecture A network's complete design—software, hardware, protocols, and access procedures—is referred to as the network's architecture. Popular network architectures include: Ethernet Token Ring FDDI (Fiber Distributed Data Interface) Ethernet Ethernet architecture is the most popular network specification, offering 10Mbps to 40Gbps transfer rates, and a bus or star topology that can use thick or thin coaxial cable (Thinnet, Thicknet), fiber optic, or twisted pair cabling. Any computer in an Ethernet passive hub network system can originate network signals as long as the lines are not busy. To gain network access, Ethernet computers use the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) method: A computer must sense that the network can handle its transmission. Many computers can use the same network. Computers must detect and handle collisions. 10GBaseT no longer uses CSMA/CD due to the technology that enables speeds of 10Gbps. As the number of Ethernet network nodes increases, speed and reliability can decrease for the entire network. Segmentation is one recommended method to counter this problem. Segmentation splits a large Ethernet network into smaller segments containing two or more computers connected by a bridge or router. A special cable, called a crossover cable, can be used to directly network two computers, without the use of a hub or switch. Crossover cables, unlike standard Ethernet cables, have the signals reversed on one end. A crossover cable is also used to connect two hubs, two switches, two repeaters, a hub to a repeater, etc. Modern hubs and switches, however, have a crossover port that uses a standard Ethernet cable (a straight-through cable). Half Duplex Versus Full Duplex The terms half duplex and full duplex describe the ability of devices to send and receive transmissions simultaneously. When Ethernet was first created, it was a half-duplex network standard, meaning that a device could not send and receive data at the same time. Half duplex is similar to a walkie-talkie, where one person can send a message but cannot receive a message at the same time. Full duplex is similar to a telephone conversation, where information can be sent and received at the same time. The 10GBaseT standard uses full duplex to achieve speeds of 10Gbps. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_4.html 2/4 Token Ring IBM developed Token Ring networking as a robust, highly reliable network. Token ring networks are generally more complex and harder to maintain than Ethernet networks. Furthermore, token ring networks are also more expensive. Token Ring stations can be physically connected in a star topology. Each station connects to a centralized hub called a Controlled-Access Unit (CAU), a Multi-station Access Unit (MAU), or a smart multi-station access unit (SMAU). The Token Ring's main network ring includes multiple patch cables, cabling to each PC on a network, and a cable connecting the last MAU (Multi-station Access Unit) "Ring Out" to the first MAU "Ring In." Each Token Ring workstation contains a token ring LAN card with a unique address. Depending on cost and needs, token ring can use STP or UTP. FDDI Another ring-based network using the token-passing traffic control method is the Fiber Distributed Data Interface (FDDI). A FDDI does not require a centralized hub like the Token Ring. At 200Mbps, FDDI transfers data much faster than either Regular Ethernet or Token Ring, and slightly faster than Fast Ethernet. Once restricted to fiber-optic cabling, an FDDI can now run on UTP cabling and can serve as a network backbone. An FDDI can even link a number of Token Ring and Ethernet networks together. FDDI’s token-passing method is much more sophisticated than Token Ring's. A FDDI can transmit more than one frame of data without waiting for it to return. Also, instead of a single ring, FDDI has two rings linking each device. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_4.html 3/4 Logical landscape Token-ring Bus Single ring Dual ring Physical landscape Bus Star or bus Ring or star Ring Media Co-ax, STP, UTP, fiber or any combination Twisted-pair, coaxial, or fiber optic cable Twisted-pair, fiberoptic cable Mostly fiber-optic cable Standard bandwidth 2.5 Mbps 10Mbps 1000Mps for Fast Ethernet 1000Mbps for Gigabit Ethernet 4 or 16Mbps 100 to 200Mbps How token is released N/A After receipt After transmit Maximum number of nodes 255 500 260 1024 Advantages Can use any combination of cabling media Least expensive and simplest Operates more reliably under heavy traffic Much faster than Token Ring, Ethernet, and faster than Fast Ethernet Networking Protocols A network protocol defines the rules that network hardware and software follow to facilitate network communications. The protocol determines the type of error checking to be used, data compression method, how the sending device indicates that it has finished sending a message, and how the receiving device indicates that it has received a message. A protocol may be used by a variety of network topologies and architectures. TCP/IP or Novell's IPX/SPX, for example, may be used by an ARCNET, Ethernet, Token Ring, or FDDI network that is physically laid out in a variety of topologies. TCP/IP The Transmission Control Protocol/Internet Protocol (TCP/IP) enjoys widespread usage. TCP/IP is the primary protocol for moving data across the Internet. Computers on a TCP/IP network receive unique addresses known an IP addresses. IP addresses are formed by four 8-bit numbers, usually written in the format xxx.xxx.xxx.xxx. For example, the IP address for the Aries website (www.aries.net) is 63.241.133.180. Item ARCNET Ethernet Token Ring FDDI Protocol Characteristics 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_4.html 4/4  Editor's Note IPX/SPX IPX/SPX is the main protocol used by Novell Netware based networks. Microsoft's implementation of IPX/SPX in Windows is known as NWLink. NetBEUI NetBEUI is a very simple protocol that can be used on small Windows based networks. NetBEUI is not routable. This means NetBEUI cannot be transferred from one network to another via a router. This limitation means NetBEUI is good for LANs only. NetBEUI is rarely used today. AppleTalk AppleTalk was designed for use with networks using Apple Macintosh computers. It is rarely used today. The term protocol is derived from the Greek word protocollon, a leaf of paper glued to a manuscript volume that describes its contents.
136820-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_5.html 1/2 Lesson 39: Networking  39.5 Peer-to-Peer vs. Client-Server There are two basic type networks: peer-to-peer and client-server. Each type has advantages and disadvantages. Therefore it is necessary to evaluate a network's needs before selecting one or the other. Peer-to-Peer (Workgroup-Based) In a peer-to-peer network, there is no centralized administrator. Each computer contains and requests resources, and no computer has special priority over any other. A group of computers on a peer-to-peer network is referred to as a workgroup. Flexibility and equality are key characteristics of a peer-to-peer network because every user on a peer-to-peer network is also the administrator of his/her workstation. In a peer-to-peer network, each user controls the access to all of the resources on his/her machine. Every user can grant unlimited access, restricted access or deny access to objects such as folders, files, and hardware. Since peer-to-peer networks lack a central security database, security must also be maintained on each system, or node. In general, peer-to-peer networks work best with a small numbers of users. Trying to implement this type of model for a network featuring more than 10 computers is a bad idea. As the number of computers increase the network's performance will suffer because workgroups are not designed to handle the demands of server-based networks. Advantages of Peer-to-Peer Easy installation and configuration Not reliant on a dedicated server User ability to control shared resources Less expensive than client/server networks Other than cables, NICs, and a usable operating system, special equipment is unnecessary Operates without a network administration specialist Disadvantages of Peer-to-Peer Network security can be applied to only one resource at a time Individual backups must be performed in order to protect shared data Users need to remember passwords for each resource No centralized directories Machines slow down as other users access resources 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson39/lesson39_5.html 2/2 Client-Server (Domain-Based) A client-server network reflects a request-and-supply relationship. In this type of relationship, a client (personal computer or workstation) requests information from a server. The network's servers maintain centralized security information, making network management easier. In order to organize a large number of computers on that can be on the network, client-server networks use domains. A domain is a group of user accounts that share a central server. Unlike a peer-to-peer network, a client-server network needs to have a network administrator to manage the network's resources, users, and permissions. Client-server networks are generally more expensive than peer-to-peer networks but they can handle a lot more traffic, workstations, and users. Although the client-server model may not be the best solution for small networks, they are ideal for larger networks. Before making a decision it is important to carefully evaluate all of your network's needs. The client-server model has a lot of advantages, but it is not a good choice for all environments. The list below outlines some of the advantages and disadvantages to this type of network. Advantages of Client-Server Networks Simplify network administration with centralized user accounts, security and access controls Provide simple, efficient access to network resources (for example: users generally have to remember only one password) Allows multiple users, many more than peer-to-peer networks, to efficiently access the network Disadvantages of Client-Server Networks Typically require expensive server hardware Server failure can cripple an entire network Implementing a server operating system requires a network administrator
136920-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_1.html 1/2 Lesson 40: The Internet  40.1 How the Internet Works The Internet began humbly in the 1960s as a modest collection of U.S. government networks within the Defense Department. Originally, the network was called the Advanced Research Project Agency Network (ARPANET). The Internet has evolved from a small government project to an integral part of everyday life. Today, the Internet is everywhere: libraries, schools, businesses, and homes. In fact, even non-Internet users can easily see how the Internet is rapidly changing how people work, communicate, shop, bank, and play. How does the Internet work? A common misconception is that the Internet is a single entity housed in some mysterious location, along with crashed UFOs and Elvis. Instead, the Internet is the world's largest Wide Area Network (WAN) and it is all around us. The Internet includes businesses, homes, and schools. Overall, the Internet includes millions of computers, holding billions of WebPages and storing trillions of byes of data, spread over more than 100 countries, providing users with access to endless topics of interest. The Internet is essentially the largest collection of interconnected computer networks on the planet. The Internet, the world's biggest WAN, links computers across states, countries, and oceans as computers communicate with other computers. This communication takes place when an Internet Service Provider (ISP) connects to a regional service provider. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_1.html 2/2  Editor's Note The regional service provider will link itself to one of many major Internet backbones that traverse the entire U.S. The backbone, in turn, connects with other backbones, providing service to locations all over America and the world. Practice safe computing to prevent viruses. Computer viruses can be transferred by infected files on a DVD or CD, downloaded from the Internet, or transferred by e-mail. The best preventive measure is to install a virus scanner and keep it up to date.
137020-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_2.html 1/4 Lesson 40: The Internet  40.2 Connecting to the Internet Internet-accessible computers have become commonplace in the workspace and in homes. Internet access has spread to once unlikely places: Internet cafes, public libraries, schools, hotels, airports, etc. Wireless services (Wi-Fi) now allow wireless enabled devices to access the Internet from Hotspots and other designated areas. Internet Service Providers (ISPs) have made it easy for users to connect to broadband services from most urban areas and many rural areas in developed countries. Most computers are Internet-ready, so a simple connection allows easy access for most users. Dial-up and broadband (high-speed) are two types of Internet connections. Dial-up Connection Dial-up is the oldest form of Internet connection, with speeds capable of only 56 kilobits per second or lower. It uses your phone line to connect to your Internet Service Provider (ISP). Also, if you only have one phone line you won’t be able to access the Internet while talking on the phone. Dial-up modems are much slower compared to cable and DSL and are rarely used in most developed areas. Accessing the Internet with a dial-up connection does not require any fancy equipment; in fact, all that is required is a modem and a free phone line. Once a modem has been installed, it needs to be connected to an available phone line. From here, a phone number is needed in order for your computer to "talk" to the remote server on the other end. Typically, your Internet Service Provider (ISP) will provide this phone number. When dialing into a corporate network, however, the company's network administrator would be able to provide this number. To gain access to the remote network, a user name and password are usually required. Dial-Up Connection in Windows 7 Use the steps below to create a dial-up connection in Windows 7: 1. Click Start → Control Panel → Network and Internet → Network and Sharing Center 2. Click on Set up a new connection or network. 3. Choose the Set up a dial-up connection selection and click Next to continue. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_2.html 2/4 4. The Internet Service Provider (ISP) is responsible for providing information needed to establish a connection. Enter the Dial-up phone number. 5. Enter the user name and password for the account. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_2.html 3/4 6. Enter a name for the connection and click Create to finish the dial-up connection wizard. Broadband Connection Broadband is a type of high-speed Internet connection. Accessing the Internet with a broadband connection requires you to have a router as well as a network device, such as a cable or DSL modem. A cable modem is used to connect a computer to cable TV services that provide Internet access, while DSL modems connect to residential public telephone service. Use the steps below to create a broadband connection in Windows 7: 1. Click Start → Control Panel → Network and Internet → Network and Sharing Center 2. Click on Set up a new connection or network. 3. Click Connect to the Internet, then click Next to continue. 4. Select option to connect using Broadband (PPPoE). 5. Enter the user name and password for the account. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_2.html 4/4 6. Enter a name for the connection and click Connect to finish the dial-up connection wizard.
137120-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_3.html 1/4 Lesson 40: The Internet  40.3 Getting Familiar with the Internet As you begin to familiarize yourself with the Internet, remember that your computer can access and exchange data with virtually any other computer connected to the Internet. For example, a student from one university can exchange information with a university on the other side of the country. While there are a number of courses, textbooks, online guides, classes and other resources available to help users learn the Internet, the best way to learn is to just get on the 'Net and go. The Internet is a tool, and the more time you spend using it, the more adept you will become. The Internet is expanding exponentially. It is becoming increasingly common to use the Internet to help construct network infrastructures, build personnel and business Web sites, take academic classes, and even purchase products or services online. World Wide Web The World Wide Web (WWW) is the largest collection of linked documents in the world, spanning local areas and the entire planet. The Web is millions of individual documents known as "Web pages." Every Web page can contain text, pictures, graphics, animations, video, sounds, and hypertext links to other Web pages. A Hypertext link permits a user to move from one Web page to another, regardless of whether a page is stored on the same server or on a server across the world. Web pages are accessed and viewed (also called "surfing the Internet") through software called a Web browser. Currently the two most popular Web browsers are Internet Explorer and Mozilla Firefox. Web pages are maintained at a Web site, which is a computer acting as a server that supports the Web's HTTP protocol. When accessing a Web site, a user is first linked to a site's home page, generally an HTML (hyper-text mark-up language) document that functions as an index, or springboard, to the rest of a site's contents. Web sites can be small or large, and as simple or complex as its designer desires. Many large organizations and businesses create and manage their own Web sites. Smaller companies and individual users depend largely on an ISP to host their Web sites. Countless numbers of individuals have created personal Web pages on a vast range of subjects. The Web, the world's ultimate research tool and resource guide, is full of information on nearly every topic known. The world has never seen anything quite as vast, and so full of potential, as the World Wide Web, and it continues to grow by the second. E-mail 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_3.html 2/4 Electronic mail (e-mail) is the transmission of memos and messages over a network. E-mail lets you send and receive text, video, sound files, pictures, graphics—even computer viruses. When working properly, e-mail is sent instantaneously. E-mail also eliminates paper. Within a local area network, users can send e-mail to a single recipient or broadcast a message to an entire mailing list. Email can be sent to anyone on the planet, as long as a recipient is connected to the Internet and has an e-mail address. How does e-mail work? Just as a physical letter makes stops at several postal stations in route to its destination, e-mail passes from one computer, known as a mail server, to another computer as it travels across the Internet. Once the e-mail message arrives at a computer called a "destination mail server," the e-mail is stored in an electronic mailbox until a recipient retrieves and opens the message. The sending-receiving process can take just a few seconds, achieving very expedient around-the-world communication. To receive an e-mail, you must first establish an e-mail account on a mail server. Having an e-mail account is similar to having a physical address where the postal service delivers your actual mail. But, e-mail's advantage is the ability to retrieve your new messages from a remote location. All that is required to retrieve remote mail is to contact your particular mail server, and download your messages. Before you can send an e-mail, you must also establish a connection to the Internet and mail server access. The standard protocol for sending e-mail over the Internet is called Simple Mail Transfer Protocol (SMTP). SMTP works with Post Office Protocol (POP) servers. To send e-mail, your computer forwards it to an SMTP server. The SMTP server scans the e-mail for an e-mail address (like the address on an envelope), and sends it to the recipient's mail server. The recipient's mail server will store the e-mail until it is "picked up" by the recipient. Web Browsers A Web browser is a software program that functions as a navigation vehicle for the World Wide Web. To go to a specific Web site or Internet address, type the address URL (Uniform Resource Locater) into a browser's location field. 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_3.html 3/4  Editor's Note  Editor's Note A URL address usually appears in a "www.aries.net" format. A Web browser takes you to any requested site and includes useful tools for manipulating information, searching the Web, saving favorite Web sites, and other helpful features. If a computer no longer boots after downloading a program from the Internet, a virus should be suspected. Always be careful of what you allow to be downloaded, and stay away from shady sites such as illegal download sites, hack sites, etc. Microsoft Internet Explorer First developed to compete with Netscape's Navigator, Microsoft's Internet Explorer is a Web browser designed by Microsoft. Internet Explorer versions exist for both Windows and Macintosh. The last version of IE for Mac was version 5.2.3. On June of 2003, the Microsoft Macintosh Business Unit decided that they would discontinue development of IE for Mac. As of 2005, Microsoft no longer supports IE for Macs. In order to increase the browser's success, Microsoft has always given away Internet Explorer for free. In addition, Microsoft integrated the browser into its operating systems, which helped Internet Explorer to become the clear market leader. Firefox, Safari, and Chrome 20-4-2018 Aries PC Maintenance and Repair: Hardware™ v.11 https://learning.aries.net/secure/content/1000001722/PCHardwareV11/unit10/lesson40/lesson40_3.html 4/4 Mozilla Firefox is a Web browser designed by Mozilla and other contributors. Firefox's source code is open source, which means it can be viewed by anyone and it is a free browser. Firefox can be used with Windows, Mac OS X, and Linux. Firefox has proven a worthy competitor to IE and will continue to improve its features, as will IE. This competition only helps users though constant functionality improvements and increased security. Apple Safari is bundled with Mac OS X and can only be used on Macintosh computers. Safari is also an open source browser. Google Chrome is a web browser released in 2008 and designed by Google Inc.. It was designed to make Web browsing easier, faster and safer. Available for Windows, Mac OS X, Linux, Android and iOS operating systems, Chrome uses a sandboxing based approach to Web security. With this method, web page run as its own process, which helps to prevent malicious code on a web page from affecting the computer operating system.