chapter system computer

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Chapter 0000: The Start of the PC

“Patience is the companion of wisdom.” -- Augustine

Chapter Objectives

The objective of this chapter is to provide the reader with an understanding of thefollowing:

1.2 Identify basic procedures for adding removing field replaceable modules for bothdesktop and portable systems.

Storage Devices; Processor/CPU; Memory; Input Devices

Hard Drive; Keyboard; Video Board; Mouse

1.3 Identify available IRQs, DMAs, and I/O addresses and procedures for deviceinstallation and configuration.

Hexadecimal/addresses

1.6 Identify proper procedures for installing and configuring SCSI devices.

Expansion slots; EISA, ISA, PCI

Jumper block settings (binary equivalents)

3.2 Identify issues, procedures and devices for protection within the computingenvironment, including people, hardware and the surrounding workplace.

Proper methods of storage of components for future use

4.1 Distinguish between popular CPU chips in terms of their basic characteristics.

Popular CPU chips (Intel, AMD, Cyrix)

Characteristics; Physical size; Voltage

Speeds; Sockets

4.2 Identify the categories of RAM (random access memory) terminology, theirlocations, and physical characteristics.


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Terminology: DRAM (dynamic random access memory)

4.3 Identify the most popular types of motherboards, the components and architecture(bus structures and power supplies)

Bus architecture: ISA; PCI; AGP; VESA local bus (VL-bus)

Gett ing Ready - Quest ions

1. The first “computer” was built for the ____ census.

2. The expansion bus in an Altair has ___ pins.

3. ISA expansion cards can be installed in an EISA slot. True/False

4. ___ - bit ISA cards can be installed in a ___-bit ISA slot

5. Both _____-_______ and ___ are 32-bit buses.

Getting Ready - An swers

1. 1890

2. 100

3. True

4. 8, 16

5. Micro, Channel, PCI


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Domain 1.0: Installation, Configuration and Upgrading

This domain requires the knowledge and skills to Identify , install, configure, andupgrade microcomputer modules and peripherals, the following established basic

procedures for system assembly and disassembly of field replaceable modules.Elements included are listed below with each test objective.

1.1 Identify basic terms, concepts, and functions of system modules, including howeach module should work during normal operation and during the boot process:

o System Board

o Power Supply

o Processor/CPU

o Memory

o Storage Devices

o Monitor

o Modem

o Firmware

o CMOS

o LCD

o Ports

o PDA

1.2 Identify basic procedures for adding removing field replaceable modules for bothdesktop and portable systems:

o Module Types:

o System Board

o Storage Devices

o Power Supply

o Processor/CPU


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o Memory

o Input Devices

o Hard Drive

o Keyboard

o Video Board

o Mouse

o Network Interface Card

o Portable system components: AC adapter

Digital camera

DC Controller

LCD panel

PC Card

Pointing devices

1.3 Identify available IRQs, DMAs, and I/O addresses and procedures for deviceinstallation and configuration:

o Standard IRQ settings

o Modems

o Floppy drive controllers

o Hard drive controllers

o USB ports

o Infrared ports

o Hexadecimal/addresses

1.4 Identify comment reports, associate cabling, and their connectors:

o Cable types

o Cable orientation


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o Serial vs. parallel

o Pin connections

o Types of connectors: DB-9

DB-25

RJ-11

RJ-45

BNC

PS2/Mini-DIN

USB

IEEE 1394

1.5 Identify proper procedures for installing and configuring IDE devices:

o Master/slave

o Devices per channel

o Primary/secondary

1.6 Identify proper procedures for installing and configuring SCSI devices:

o Address/termination conflicts

o Cabling types (example: regular, wide, ultra-wide); internal vs. externalexpansion slots, EISA, ISA, PCI

o Jumper block settings (binary equivalents)

1.7 Identify proper procedures for installing and configuring peripheral devices:

o Monitor/video card

o Modem

o USB peripherals and hubs

o IEEE 1284

o IEEE 1394


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o External storage

o Portables: Docking stations

PC cards

Port replicators

Infrared devices

1.8 Identify hardware methods of upgrading system performance, procedures forreplacing the basic subsystem components, unique components and when to use them:

o Memory

o Hard drives

o CPU

o Upgrading BIOS

o When to upgrade BIOS

o Portables: Battery

Hard drive

Types 1, II, III cards

Memory

Domain 2.0: Diagnosing and Troubleshooting

This domain requires the ability to apply knowledge relating to diagnosing andtroubleshooting, module problems and system malfunctions. This includes knowledge ofthe symptoms relating to common problems.

2.1 Identify common symptoms and problems associated with each module and have totroubleshoot and isolate the problems:

o Processor/memory symptoms

o Mouse

o Floppy drive


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o Parallel ports

o Hard drives

o DVD

o Sound

o Sound card/audio

o Monitor/video

o Motherboards

o Modems

o BIOS

o USB

o NIC

o CMOS

o Power supply

o Slotcovers

o POST audible/visual error codes

o Troubleshooting tools e.g. Multimeter

o Large LBA, LBA

o Cables

o Keyboard

o Peripherals

2.2 Identify basic troubleshooting procedures and how to elicit problem symptoms from

customers:

o Troubleshooting/isolation problems determination procedures

o Determine whether hardware or software problem

o Gather information from user regarding, e.g.


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o Customer environment

o Symptoms/error codes

o Situation when the problem occurred

Domain 3.0: Preventive Maintenance

This domain requires the knowledge of safety and preventative maintenance. Withregard to safety, it includes the potential hazards to personnel and equipment andworking with lasers, high-voltage equipment, ESD, and items that require specialdisposal procedures to comply with environmental guidelines. With regard to preventivemaintenance, this includes knowledge of preventive maintenance products, procedures,environmental hazards, and precautions when working on microcomputer systems.

3.1 Identify the purpose of various types of preventive maintenance products and

procedures and when to use them:

o Liquid cleaning compounds

o Types of materials to clean contacts and connections

o Non-static vacuums (chassis, power supplies, fans)

3.2 Identify issues, procedures and devices for protection within the computingenvironment, including people, hardware and the surrounding workplace:

o

UPS (Uninterruptible Power Supply) and suppressors

o Determining the signs of power issues

o Proper methods of storage of components for future use

o Potential hazards of public safety procedures relating lasers: High-voltage equipment

Power supply

CRT

o Special disposal procedures that comply with environmental guidelines: Batteries

CRT's


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Toner kits/cartridges

Chemical solvents and cans

MSDS (Material Safety Data Sheet)

o ESD (electrostatic discharge) precautions and procedures: What ESD can do, how may be apparent, or hidden

Common ESD protection devices

Situations that could present a danger or hazard

Domain 4.0: Motherboards / Processors / Memory

This domain requires knowledge of specific terminology, facts, ways and means ofdealing with classifications, categories and principles of motherboards, processors inmemory in microcomputer systems:

4.1 Distinguish between popular CPU chips in terms of their basic characteristics:

o Popular CPU chips (Intel, AMD, Cyrix)

o Characteristics

o Physical size

o Voltage

o Speeds

o On board cache or not

o Sockets

o (SEC) single edge contact

4.2 Identify the categories of RAM (random access memory) terminology, theirlocations, and physical characteristics:

o Terminology: EDO RAM (extended data output RAM)

DRAM (dynamic random access memory)

SRAM (static RAM)


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RIMM (Rambus in-line memory module 184 pins)

VRAM (video RAM)

SDRAM (synchronous dynamic RAM)

WRAM (Windows accelerator card RAM)

o Locations and physical characteristics: Memory bank

Memory chips (8-bit, 16-bit, and 32-bit)

SIMMS (Single in-line memory module)

DIMMS (dual in-line memory module)

Parity chips vs. non-parity chips

4.5 Identify the most popular types of motherboards, the components and architecture(bus structures and power supplies):

o Types of motherboards: AT (full and baby)

ATX

o Components: Communications ports

SIMM and DIMM

Processor sockets

External cache memory (level 2)

o Bus architectures: ISA

PCI

AGP


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USB (Universal serial bus)

VESA local bus (VL-bus)

o Basic compatibility guidelines: IDE (ATA, ATAPI, ULTRA- DMA, EIDE)

SCSI (wide, fast, ultra, LVD (Low Voltage Differential)

4.4 Identify the purpose of CMOS (complementary metal-oxide semiconductor), what itcontains and how to change its basic parameters:

o Printer parallel port - Uni, bi-directional, disabled/enable, ECP, EPP

o Com/serial port-memory address, interrupt request, disable

o Floppy Drive-enable/disable drive or boot, speed, density

o Hard drive- size and drive type

o Memory-parity, non-party

o Boot sequence

o Date/Time

o Passwords

o Plug & play BIOS

Domain 5.0: Printers

This domain requires knowledge of basic types of printers, basic components, andprinter components, how they work, how they print onto a page, paper path, care andservice techniques, and common problems.

5.1 Identify basic concepts, printer operations and printer components:

o Paper feeder mechanisms

o Types of printers

o Laser

o Ink jet


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o Dot matrix

o Types of printer connections and configurations: Parallel

Network

USB

Infrared

Serial

5.2 Identify care and service techniques and common problems with primary printertypes:

o Feed and output

o Errors (printed or displayed)

o Paper jam

o Print quality

o Safety precautions

o Preventive maintenance

Domain 6.0: Basic Networking This domain requires knowledge of basic networking concepts and terminology, abilityto determine whether a computer is networked, knowledge of procedures for swappinginto figuring Network Interface Cards, and knowledge of the ramifications of repairswhen a computer is networked. The scope of this topic is specific to hardware issues onthe desktop and connecting it to a network.

6.1 Identify basic networking concepts, including how network works and theramifications of repairs on the network:

o Installing and configuring network cards

o Network access

o Full-duplex, half-duplex

o Cabling-twisted pair, coaxial, fiber-optic, RS-232

o Ways to network a PC


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o Physical network topologies

o Increasing bandwidth

o Loss of data

o Network slowdown

o Infrared

o Hardware protocols

o II Start of IT and the History of Computing o If you are very familiar with PC‟s (personal computers) you can safely skip the

history lesson. Fair warning that skipping yesteryear data will deprive you of thedata for some fun bets you are sure to win (unless the opposing party has alsoread this book .

o Data you really need to know begins with the Success Owl regarding 8-bit vs.16-bit data paths. If that sounds like Greek to you, then it is important to read thehistory lesson.

o You will learn the different ways computer manufactures offered expansion capabilities to their hardware.

o After examining the sub systems that are the parts of the PC you will learn theprinciples of electricity. Building on your newfound understanding of electricity,you will discover how electronic components behave and how to visuallyIdentify them. Visual explanations augment the discussion.

o Finally, you will garner an understanding of how Base2 (binary) math relates toboth Base10 (everyday math) and Base16 (hex) math, without needing to be a„propeller head‟.

IT Starts

Many consider the first computer to be an invention by the Americanknown as Herman Hollerith. This machine read punch cards, to tie thelatest statistics for the 1890 census. (He got the idea from his brother back

in Europe, when reading his letter about the new weaving looms operated.) Hollerithsold the US Congress on the idea. (Computing first vaporware product) The 1890Census was completely done in months, not years. And distilling data such as “howmany wheat farmers live in Ohio?” became feasible. Hollerith was a smash hit. Later,

financial difficulties forced the sale of this machine to a firm known as ComputerTabulating Recording (CTR). A former salesman of player pianos at the time wasThomas Watson, who was working with CTR. Eventually, Watson took over thecompany, renaming it IBM.

IT Starts Here


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Companies such as Digital Equipment Corporation (DEC) were building small-sizedcomputers known as min icomputers , which benefited the smaller business company.However, even the smallest minicomputer was actually too large for small business orhome use.

Ed Roberts in Albuquerque, New Mexico addressed the idea of the personal computer(PC) by the founding of a company known as Micro Instrumentation TelemetrySystems

(MITS). This former creator of radio control devices released the computer known asthe Altair , which began the microcomputer revolution (seehttp://www.exo.com/~wts/mits0013.htm).

Several concepts made the Altair unique. It was small-sized in both computationalpower and physical size. It was sold in kit-form, which kept selling prices low.

The Altair was made expandable by the induction of sockets allowing for plugging ofextra boards (expansion). The sockets (connectors ) had 100 pins, which ultimatelybecame known as the S-100 bus.

Mainframes

Companies such as International Business Machines (IBM) were buildinglarge-sized computers known as mainframes , which carried equally largepurchase and operational costs.

Microsoft

The issue facing MITS was the computer was programmed with 8 on/off switches. Thismade programming a tedious effort at best.

The appearance of a solution showed up in a letter sent to MITS from a firm marketing aprogram called Traf-O-Data. This company was a part-time business for a couple ofhigh school students named Bill Gates and Paul Allen.

They offered a computer language known as BASIC to MITS. Let's not forget thetrivial point that neither of these individuals actually had this language for the Altair.

BASIC was available in the public domain for different CPUs (Central ProcessingUni t ), which is considered the computer‟s brain.

Their prior experience of using a simulator on a DEC computer for Traf-O-Data allowedthem to work a few frantic weeks through which they were able to make BASIC work onan Altair without the experience of ever having seen one. (Emulators or simulatorsallow you to write programs on one system to run on another system.)

http://www.exo.com/~wts/mits0013.htmhttp://www.exo.com/~wts/mits0013.htmhttp://www.exo.com/~wts/mits0013.htm


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With the success of their efforts, Paul Allen went to work at MITS and Bill Gatesdropped out of Harvard and moved to Albuquerque.

The two individuals granted a non-exclusive license to MITS, which made manyhobbyists, resent them. Their point was that BASIC had come from the public domain

and they had used government-funded computers to pirate BASIC for the Altair .

These young men founded a new firm to market BASIC to other firms makingmicrocomputers. They called this firm Microsoft.

Apple

At this same time, another group of young men, comprised of Steve Wozniak, RonWayne, and Steve Jobs were looking at the Altair with the realization that a home computer was a really cool idea.

The down side of this idea was that the hobbyist needed specific skills such assoldering. So, Steve Wozniak sat down in his bedroom and created a ci rcui t board ,dropping it into a wooden box, complete with its own version of BASIC hard-coded(fixed) into the computer. Ron Wayne wrote the manual, and Steve Jobs marketed theintended game machine to anyone who would listen.

Those listening included Paul Terell, the owner of the only computer store chain inexistence, The Byte Shop. One year later, the Apple II came out, and this time,Wozniak put in 8 expansion slots . Expansion slots let you add functionality to acomputer.

CP/M

To round out the early days of the microcomputer revolution, we need to introduce aSeattle native and student of the University of Washington.

Enter Gary Kindall, computer science graduate of 1972. At this time, the pair whofounded Micro Soft was working part-time in the university district of Seattle.

Gary, like Paul & Bill had a love for the DEC computer . After completing a tour for theNavy, Gary founded the company Intergalactic Digital Research.

One of his projects was to write an operat ing system for microcomputers called theContro l Program Microcomputer (CP/M). Gary incorporated features he liked fromthe DEC operating system to the Contro l Program Microcomputer .

Because CPU designs need to be bonded to an operat ing system , Gary wrote asecond operating system specifically for the Intel Microprocessor , calling itProgramming Language for Microcomputers PL/M.


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Intel

Intel currently was busy creating a fortune with the 4004 CPU that is used incalculators.

They were not a dominating factor in the supply of CPUs for microcomputers. OtherCPUs such as the Zilog Z-80, as well as offerings from Motorola dominated the field.

With this, CP/M from the renamed Digital Research, Inc. (DRI) became the dominantoperating system, with Microsoft (now without a space) being the dominant computer language firm.

Killer App

All that was missing at this time was a task automation tool. It was so widely needed;it was virtually guaranteed that everyone would buy it. Today that “market hole” isknown as a “Killer App”. A man named Donald Bricklin unveiled the first killer app.

Donald Bricklin was a programmer of (what else?) DEC computers. Seeing thepossibilities for microcomputers, he came up with the idea of creating a program tobuild financial models and have the computer crunch (process) the numbers. Thebasic idea was simple, create a traditional accounting worksheet but hook everythingtogether so that values you change in one area is then reflected in the rest of theworksheet.

Think of it as a calculator program that would show results visibly on the screen. And, that is the where name of the program, VisiCalc , came from. By now, youprobably won't be surprised to hear that Donald didn't own an Apple II, or for thatmatter, any microcomputer at all. The VisiCalc development project began using asimulator (approximate) running on a, you guessed it, DEC.

Businesses large and small could create what-if scenarios and business forecasts in amatter of hours, as opposed to weeks or months, for only a few thousand dollars.Naturally this phenomenon caught the attention of the world's largest computer supplier,IBM.

III IBM and the Creation of the PC

What to do about "toy computers" caused some rather heated discussions within IBM.In the end, IBM management selected "Dashing" Don Eldridge to create an IBMPersonal Computer . They sent Don down to the Florida coast, where if the projectfailed, one swift kick would drop the project into the ocean.


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Various rumors and stories about what happened between Gary Kindall and IBM abounded. The bottom line is that the two companies did not make a seriousconnection. IBM had Bill Gates sign a strict Non-Disclosure Agreement and askedhim what he wanted to see in a microcomputer . Always ready with an opinion, Bill toldthem exactly what he wanted to see. After the misfire between IBM and DRI, and since

Bill and company had previously sold IBM the computer language BASIC, it was agood opportunity to see if the Seattle company had an operating system.

Not one to miss an opportunity, Bill Gates answered with an affirmative. While Microsoftdidn't actually have an operating system, a poker buddy named Tim Patterson did.

DOS

Tim Patterson was working hard at a small firm called Seatt le Computer Prod ucts . Inreality, Seattle Computer Products wasn't in Seattle at all; it sat in a little Seattle suburbon Industry Drive in Tukwila, Washington. Their flagship product was a Computer

Aided Design and Draft ing (CADD) computer. Tim had a challenge. LP/M crashedwhen it attempted to work with the then super fast 8086 CPU. So, Tim created GazelleDOS .

Bill offered to buy Gazelle DOS , outright, neglecting to mention his relationship withIBM (remember the NDA?). In the end, Microsoft came to an agreement with SeattleComputer Products , which allowed Tim to keep Gazelle DOS for his own use as longas it bundled (sold) with a CPU , and received $50,000.00 to allow Microsoft's use ofDOS. (Tim later used that funding to start Falcon Computer Products, with the first itembeing a very fast hard drive controller.)

Reportedly, Microsoft l icensed DOS to IBM for one dollar per copy, with theprovision that Microsoft could license DOS to other vendors.

IBM PC

IBM released the PC Model 5150; it had five expansion slots utilizing an eight-bitdata path. It could accept up to four floppies (5.25 inch disks), or work with anaudiocassette to store programs. The marketing clout of a PC with IBM's name on itsurprised even IBM. However, it was a few third-party vendors that made the IBM PC arun-away success.


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Figure 1: 8088 CPU & 8087 CPU. The 8088 CPU (bottom) was selected over the8086. 8087 Math Co-processor (top) optional

Lotus

A small company in Massachusetts created a rival to VisiCalc to run on the 5150.That firm was called Lotus Development Corporation. The VisiCalc competitor wasknown as 1-2-3 . What was missing in the IBM line up was an impressive video display.You either had to settle for monochrome and text, or low color, low-resolution colorgraphics.


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Hercules

A firm called Hercules created a monochrome card (video card) that could displaymono graphics. This is just what 1-2-3 needed to convert what-if worksheets intographic representations.

The Combination

Combining these elements created such a market force that IBM had to release anew version, the PC-XT. This unit had a larger power supply, which it needed tosupport the built-in 10MB hard drive. Within two years, IBM went from zero to hero inpersonal computing. At that time, it appeared that IBM had won the race. The industry wasn't keeping a close enough eye on the Apple.

Xerox

Back in California, there was more to computing than Apple. In fact, right around thecorner from Apple, the copier company Xerox had a little think tank known as Palo AltoResearch Center (PARC). Since Xerox had invested $1 million in Apple, the firm didn'thave major heart burn letting a few key Apple executives see what they were doing atPARC.

What Steve Jobs and a few others saw in action was science fiction stuff like: thecomputer mouse, graphical icons on the screen to represent programs and computermanagement, laser printing, and computer network ing (what would becomeEthernet ), as well as other Buck Rogers sci-fi stuff.

Xerox management didn't really care about letting Apple see the cool work at the thinktank, however, some of the managers at PARC did! After all, they were a copiercompany right? What came out of this was the Lisa. What was the Lisa? At $10,000.00computer that was a marketing bomb. Almost no one could afford it.

Mac

This 52-pound monster may have been on the market for about one year. Despite theill-fated future of the Lisa (the last of them became landfill near Logan, Utah), it

spawned a successful offspring called the Macintosh.

Compaq

IBM was quick to get its PC to market, in less than two years, in part because DonEldridge, who was in charge of the project that had designed the 5150, IBM's firstsuccessful PC, using mostly off-the-shelf parts, an idea successfully demonstrated withthe Altair . In fact, only two parts were of IBM design, the BIOS (Basic Input/Output


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System) and keyboard decoder . This left many firms attempting to cash in withcomputers known as "compat ib les ". How compatible did compatible mean? Well, itcreated untold grief.

The best-known truly compatible computer came from a Texas company known as

Compaq. Besides the fact that it worked, Compaq had one big thing going for them,like an Osborne 01, and the keyboard could be attached over the front of the f loppydrives and monitor . This enables it to be hauled around, with the same grace ashauling a sewing machine. This was marketed as a portable PC, and a more accurateterm that soon became popular. These and others became known as " luggable"computers.

Pop Quiz 0000.00 (Page 1 of 2)

Quest ions

1. DOS, UNIX, C/PM all have similar interfaces because all the peopleworking on new designs got their experience working on ___ computers.

2. The two components IBM created 'in house' for the IBM PC were the ______and the ________ _______.

Answers

1. DEC

2. BIOS, keyboarddecoder


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IV PC Technology Evolution

Standing in the year 1983, we have:

The IBM PC, a "portable competitor" and The Macintosh.

A computer interface using icons was obviously so much more intuitive that both IBMand Microsoft each had plans of their own for an icon-based operating system. IBM released their version known as TopView, while Microsoft called their graphical operating system Windows . Today we call these operating systems with icons, theGUI (graphical user interface).

IBM's desire to distance itself from Microsoft with TopView did little to help thecooperative effort for a next generation operating system called OS/2 .

The final tear in the relationship was IBM's insistence that OS/2 run on the 80286 CPU

(the marketing name for this 1985 entry was the IBM AT , or Advanced Technology).Microsoft was convinced that the entry point for the new operating system should bebased on the much more advanced 80386 CPU.

8-bit verses 16-bit Data Paths

To stay backwards compatible with the PC, the AT introduced a 16-bit ISA data path by adding a second connector to the 8-bit ISA slot. This way oldercards could be retained and used as 8-bit components.


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Figure 2: 8-bit & 16-bit cards. The contacts of the card connect to a slot. See thedifference between the shorter 8-bit card and the longer 16-bit card.

Types of Switches

Even with today‟s Plug and Play, sometimes a device needs to have aconfiguration set. There are two typical ways to accomplish this. One is withswitches the second is with jumpers.


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Figure 3: A typical switch block. On and off can quickly be changed with aballpoint pen.

Park ing Jump ers

When you want to keep a jumper attached to a device without it completinga circuit, you hang it (attach it) on one connector . This is sometimes calledparking the jumper .


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Figure 4: Jumpers, on/off (parked). Jumpers are like switches, but easier to lose.Note the „parked‟ jumper, second from the left

PS2

Personal computer sales that were generated mostly from companies other than IBM skyrocketed.

In 1986, Compaq bested IBM by being the first company to release a PC based on the386. One year later, IBM responded to the „clone invasion‟ by releasing a newcomputer line-up, known as the Personal System 2 or PS/2 for short.

This new line of computers hosted an array of innovations including a new andcompletely incompatible method of accepting expansion cards. This new expansion buswas known as Micro Channel Architecture (MCA). IBM welcomed its competitors touse MCA, by paying a 'mere' dollar per slot for every computer made. Nobody wasgoing to pay that, even if it was a 32-bit data bus.


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Figure 5: The MCA card above looks very similar to today‟s PCI card. The plastictab on the card is the MCA clue.

EISA

Looking at millions of dollars in royalties, nine companies called the Gang Of Nine,formulated an alternative to the MCA expansion slot.

The Gang of Nine -- AST, Compaq, Epson, HP, NEC, Olivetti, Tandy, WISE, Zenith --took the royalty free expansion design of the IBM PC, known as Industry StandardArchitecture (ISA), and then, went down below the electrical contacts of the ISA expansion bus to create a second row of contacts and called this Extended IndustryStandard Architecture (EISA).

With this creation, the battle of the 32-bit expansion bus began.


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Figure 6: ISA and EISA cards. An ISA card could be used in an EISA basedsystem board.

VLB

The battle of the expansion bus left one group of manufacturers very unhappy. Who

would want to design and make video cards for two different incompatible systems?The Video Electronics Standards Association (VESA) created the Video Local Bus (VLB), as an extension of ISA in an attempt to improve video performance and makeonly one type of video card.

The VESA-VLB bus was the slot to have when ordering your new 80486 computers.While this offering greatly improved video performance, VLB died in the bus wars withthe introduction of a new bus from Intel.


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Figure 7: A VLB card is easy to Identify. It always has contacts on the other end

of the card.

PCI

While the bus wars loomed for several years, Intel ended it all by coming out with aroyalty free expansion bus known as the Peripheral Comp onent Interconn ect (PCI).

This made Intel's stockholders very happy. Why? Unlike the VESA-VLB, PCI uses ach ip set to control it, and, what does Intel make? Why chips of course.

So, here you have a new and very cool 32-bit expansion bus that will end the bus wars.

Oh, you need a set of chips to control the expansion bus? Well, we at Intel can help youwith that!! (Tcat has never worked for Intel!)


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Figure 8: PCI card. Notice that PCI contacts are narrow compared to ISA ones.

The PCI bus entered the stage in 1993. Near the end of the century, the PCI bus wasfinally overtaken by advances in other sub-systems, such as hard drive data transferrates, as well as CPU and memory transfer rates. In Chapter 0001 you will see how thePCI bus gets a new lease on life.

2002 and Beyond


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Of course, other battles in the IT (Information Technology) were brewed and fought inevery area worth fighting over. Some of the lesser-known conflicts will appear in thepages that follow. We hope that this brief tour in the digital art of war helps youunderstand where we were, so in the following pages you understand where we arenow and where we are going. In the next few pages, you will discover the various

parts of a computer system, and how it is like today's modern office.

Subsystems

In many ways, a computer system is like an airplane. They are both a collection ofspare parts flying in close formation.

In each case, they are a system that depends on the close timing and performance of a number of subsystems. In the computer case, there are three majorsubsystems. They are the CPU, RAM, and storage.

CPU

The first subsystem is the Central Processing Unit (CPU).

This is the brain that would be considered central command. In a desktop metaphor,the CPU is you sitting behind the desk, deciding what to do next and controlling theflow of action.

RAM

The second subsystem is the Random Access Memory (RAM). The computer

functions much like your desktop where you spread your work out.

How much RAM you need, depends on how much work must be spread out. Themore projects you have going at the same time, the more desktop you need. Thesame could be said of RAM. A large program or even a series of small programs allconsume this resource.

Storage

The third subsystem is storage, such as a hard drive. Using the desktop analogy,the hard drive or CD acts as a filing cabinet for your projects. Just as in the physical

office, the more projects you need to store, the more storage space you need.

Further, the more drawers you have to stuff things in, the better the chances are for aparticular file to be lost in the clutter . 'Spring cleaning' a large hard drive can be justas joyous as cleaning an attic with 30 years of collectibles.


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Where’s the bottleneck?

When looking at these three major subsystems, RAM is typically the largest bottleneck slowing system performance. The CPU is generally the second most likely culprit, while improving hard drive performance typically gives

the least improved performance. Of course these are just general thoughts and yoursituation can and will vary.

A common denominator among all these components is the fact that they needenergy to make them work. In the next section we will dig deeper into that energysource.

V Electricity

Frequently misunderstood and often feared, electricity is a basic form of energy found in nature. To understand the nature of electricity, begin by looking at the smallunit called the atom.

In the center of an atom is a nucleus.

An atom is composed of both positive and negative electrical charges.

Spinning around a nucleus are electrons. Electrons have a negative charge.

Protons have a positive charge, and, as the name implies in neutrons, they are

neutral or have no electrical charge.

Typically an atom has an equal number of electrons and protons.

Many of our elements found on Earth have the possibility to dislodge one or moreelectrons spinning around the nucleus. When this happens the atom has morepositive than negative electrical properties, and, is known as a positive ion.

If a dislodged electron joins another atom, the electrical balance becomesnegative and is known as a negative ion.

Electrons Unleashed

Remember that an atom doesn't weigh very much, and the electron is a very small part of an atom. This means an electron has almost no weight.

Electrons not attached to the orbit of an atom are known as free electrons.


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A property fact of free electrons is they move at a very high speed (about 186,000mi. per second) traveling through metal, many gases, or a vacuum.

If an electron isn't flying around, it can rest on a surface.

When a few trillion free electrons are sitting around on a surface, this is known as anegative static electrical charge.

Electr ic B ehavior

To have electricity, the free electrons need to have positive ions waiting for them and a way to get there.

By using friction, light, chemicals, or heat it is possible to create a surface with a

positive static electrical charge.

If you ever walked across carpet and felt the static electricity make you jump as youreached for a light switch, you experienced creating electricity by mechanicalfriction. Electricity behaves the same way a magnet does. That is to say oppositecharges attract, like charges repel.

Insulators and Conductors

Some materials hold onto their electrons very tightly and resist giving up their

electrons. These materials are known as insulators.

Types of Insulators

Glass, rubber, wood, and plastic are good insulators.

Other materials give up their electrons very easily. These materials are known asconductors.

Types of Conductors

Copper, silver, gold, aluminum, and iron are good conductors.


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Completing a Circuit

At this point it is clear to you that electricity cannot move without a complete path.When designing a circuit board, a common return path is created that is calledground .

Ground shows up prominently in all aspects of the PC and in this book.

Connect ion Poin t Ground

A connection point that is ground for a PC component is typically known aspin 1.

Ident i fy ing Pin 1

Sometimes Identifying Pin 1 can be an elusive task. Frequently a trick thatworks is to look at the backside of a circuit board and looked for a solderconnection that is square instead of round. If you can find that, you found

pin one.


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Figure 9: Notice the one connection point is square. This indicates Pin 1 orground.

Magnetic Fields

When electrons travel it is called electrical current. When this happens the electrons create a magnetic field. This behavior can be useful for creating measurementdevices, or, it can muck up data signals.

Measuring Electricity

In many ways, electricity behaves like water . When stored up, it has the potential togo somewhere. When it flows, it wants to take the path of least res is tance . To furtherunderstand how electricity is measured, let's compare it to water .

Think of a water tank filled with water mounted on a pole. The water in the tank is thepotential energy. If you hook a hose to the water tank, and open the valve, thewater will flow out the hose. The higher the water tank is on the pole, the faster thewater will come out. This is known as water pressure. When measuring electricalpressure, the unit of measurement for pressure is called voltage, or, V in itsshorthand. Work performed by electricity is called power or, P in its shorthand. Themeasure of current is called amps. The formula is known as E=I x R, which is called Ohm‟s Law.


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Remember the water valve you turned on to let the water out of the tank? Youcontrolled the amount of water with the valve by impeding the flow of water . In otherwords, you gave resistance. In electricity, resistance is measured in ohms, frequentlyexpressed with the symbol, and named after the guy who discovered the mathrelationship between voltage, current, resistance, and power . The shorthand for

ohms is either or R.

AC/DC

Electricity can flow in either direction. If it only moves in one direction, it is calledDirect Current (DC). Remember the idea expressed earlier that as electricity flows italso makes a magnetic field? Well if you spin a bunch of wires between twomagnets, (which you might do with, say a waterwheel) you get electricity that swings back and forth between positive and negative charges creating Alternating Current (AC).

Multimeters

As stated above, the magnetic field can be used to measure electricity. Typically,meters have more than one function since the relationship between resistance,voltage, etc., is so closely bound. Devices with multiple measurement capabilities are called multimeters.


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Figure 10: On the left is a Digital Volt/ohm Meter (DVM). On the right is an Analogmeter.

DANGER!

The mark enclosed in a triangle on both meters indicates the potential formeasuring dangerous electrical levels.

Cycles Per Second (CPS)

So far, we know that electricity can flow as AC or DC. Who said the flow must becontinuous? It doesn't have to be. Further, there is no law of nature that demands thatvoltage remain constant. It is technically possible to vary the number of oscillations between positive and negative sweeps in AC, and to vary the amount of DC current or even turn it on and off to create pulses.


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When you have an AC current the number of sweeps between positive and negative is measured in Cycles Per Second (CPS). Electricity in North America is deliveredat 60 CPS, with the pressure of 120 volts. Sometimes this is expressed as 120VAC. InEurope, the standard is 50 CPS and 240VAC. In computers, we describe CPS usingHertz, or Hz. A device that operates at 1000 CPS is running at 1KHz.

Intel l igent Life

Vary either voltage or the CPS, a process known as modulation occurs. Thisis how radio and TV work. The stream is more or less continuous and isconsidered an analog signal.

Taking DC and turning it on and off , or, pulsing the voltage is the basis for a digital signal. For example, 5VDC could be a one, and 1VDC or even a negative voltage could signify a zero.

With the basics of electrical properties complete, let's look at a few electroniccomponents.

The Numerous Won ders of Electr ic i ty

The above example does not cover how AC and DC can co-exist on thesame wire, or other more advanced topics, such as saw tooth waveforms.This book will not cover more esoteric concepts such as skew (which can be

a real challenge in SCSI devices). The intent of this book is to prepare the reader for A+

certification. We have more than covered electricity as a testable concept in thischapter. However we encourage any reader who wishes to know more to start withGetting Started in Electronics. Forrest M Mims III, available at Radio Shack.

Resistor

A resistor can come in a great variety of different packages. And regardless of theform it comes in, the job of a resistor is to resist or limit current.

If you have ever seen a little tube with wires on both sides and little color rings aroundthe tube, you have visually identified a resistor .

The colors are values telling you the amount of resistance in ohms (.


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Figure 11: Carbon resistors. The bands of paint are value displays.

How to Read Color Codes on Resistors

Locate the Gold or Silver Band. Go to the other end to start counting. Look upthe numbers for 1st two colors. Use band 3 as a multiplier.

Gold band = 5% of rating, Silver 10% of rating.

Capacitor

As with resistors, capacitors can also come in a great range of different packages.The role of capacitors is to store electrons.

Remember the water tank? Think of a hand pump at a well. The water comes out ofthe pump in spurts. If the water is held in a water tank, a valve can be opened,getting a continuous stream of water. So, a capacitor can behave like a water tank

to smooth out uneven electrical flow.


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Figure 12: Capacitors.

Capaci tors in PCs

Typical capacitors found on a systemboard or expansion card. Largercapacitors are found in power supplies.

Transistor

Let's look at the transistor next. If you have water flowing through a pipe, and, youput a valve in the middle of the pipe, you can control the amount of water that isflowing through the pipe by controlling the valve. A transistor works the same way.

Electricity flows in one wire and out the second wire. Applying electricity to a thirdwire, controls flow that acts as the valve regulating the amount of electricity thatflows.

In the simplest of terms, this is how an amplifier works. A small amount of electricity is used to control a larger amount of electricity.


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Figure 13: A typical modern transistor. 30 + years ago they looked like little

aluminum „top hats‟.

Diode

One final electronic piece is the diode. Again, diodes come in many flavors. A diode lets electricity flow easily in one direction, and, offers resistance in the oppositedirection.

Diodes can be used to filter out the negative swings of AC, leaving only bursts ofpositive voltage. Take only the positive burps of power and send these to acapacitor , and, what comes out is DC voltage.


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Figure 14: A typical diode. The band indicates the negative (-) side.

LED

A specific type of diode is very popular in computer equipment. That is the LightEmit t ing Diode (LED).

It is used to indicate something is on, working or busy. A pair of typical LEDs forcomputers appears in Figure 15.


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Figure 15: A pair of LEDs. Some LEDs have a multi-color output that can be used

to indicate different states of operation.

Fuse

The last piece of the puzzle is still missing. While it is very low-tech in nature, it is,nonetheless, invaluable. This is the fuse. A fuse can be as simple as a piece of metal held in either glass or plastic.

The fuse conducts electricity readily in normal operation. If an issue arises in thecircuit causing it to draw more current than normal operation calls for, the excesscurrent heats the metal to the melting point, breaking the circuit so the electricity stops

flowing.

Good Fus e Bad Fuse

A good fuse will offer no resistance, and, shows zero ohms on a Multimeter. A

bad fuse will not conduct electricity, and, shows infinite resistance ( onmultimeters.


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With all the pieces of basic electronics defined, think about how much space is takenby putting all these parts on a board to connect them together so they do something for us. If we could get rid of some of the packaging and wires for the different parts,

we could have devices that are smaller , lighter , consume less electricity, and, evenbe more reliable. This idea is explored next.

Integrated Circuit (IC)

The Integrated Circuit (IC) is the same stuff that made the capacitors, resistors, andtransistors possible. The difference is the parts are laid out to perform a specificfunction, without all the packaging of the individual parts. The whole range of parts isthen placed in one package. Today, the insulation between the parts is literally only afew atoms thick!

Figure 16: Typical appearance of an intergrated circuit (IC).

A single IC can contain millions of transistors, capacitors, diodes and resistors. This

is called Very Large Scale Integrated Circuit (VLSIC).

Due to so much being packed in such a small area, very small amounts of power areused to keep heat to a minimum, and to prevent insulators within the IC from beingoverrun. Today it is not uncommon to see voltage requirements of less than 2 volts foran IC. A CPU is a good example of a VLSIC. In May 2001 a research firm managed tosuccessfully create an insulation layer that is one atom thick. This is the ultimate goal


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following the current design approach. A new method is being researched to keepadvances continuing.

At this point, you have seen how electricity works, and, the common components in useto make electricity do something useful for us. Now it is time to apply some logic so the

computer can do some 'thinking'. How a computer thinks is the next topic.

Loose Connectors

If you were required to know every connection type ever made, nobody would be A+certified. And for the test that the Real World throws, you may need to know about theconnectors pictured in Figure 0.17. These small connectors fit on pins found as part of asystemboard.

Where do the LEDs and Switches Plug into the Systemboard?

The short answer is: „lots of luck figuring it out‟. The sad truth is there simply isno standard. Further, there is no rule that requires labeling in a native tonguesuch as English as seen in Figure 17. You may find obscure markings, or no

markings at all, leaving you clueless.

And the motherboard may have plain marking, or cryptic coding such as J-14 to J-29.Without a manual you are usually better off not spending a great deal of time if youcouldn‟t note the working combination before you started .

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Figure 17: If you are lucky, the leads to a PC case are labeled. Notice that thePower LED here skips the 2nd pin.

Pop Quiz 0000.01 (Page 1 of 2)

Quest ions

1. Name the 32-bit buses.

2. A triangle on a Multimeter setting indicates __________.

3. The symbol for ohms is __.

4. The real world voltage for modern CPUs is about ___ volts.


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Answers

1. EISA, VLB (VL-Bus), MCA,PCI

2. Dangerous/fatal levels of electricity.

3.

4. 2

VI Binary Math

As mentioned previously in this chapter, a complex system such as a computer is reallya collection of simpler devices.

In the everyday human world we work with numbers. We work with numbers that themathematicians call base 10 math because most of us have ten digits (five on eachhand).

Think for a moment about how we count. Starting with zero, we move to one, two,three, etc. After reaching the number nine, we have exhausted the possible amount ofnumbers if we included the value zero. That means we have used 10 different values,so base 10.

What are we really saying when we say 10? Think of the numbers arranged incolumns. The first column when using 2 numbers will be the unit column; thesecond column will be the numbers column. Breaking this value down means wehave zero value in the unit column, and, we have a single 10 in the tens column. Ifthe value was 70, that is the same as saying there is a grand total, of 7 tens in the tenscolumn.

If the value was 88, it is the same expression as 8 tens and 8 units. In other words, wemoved over to the left one column. After 99 the next number is 100. Again, we havemoved over one column, leaving no value in the tens column and no value in theunits column.

When you look at a computer closely, it really is not very intelligent. In fact, it is verydumb; it can only count starting from zero, up to one. That's it. Only two possible values


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exist at the base level of a computer. Zero and one or off and on. Zero represents off and one represents on. So what happens if you need to count to a number bigger thanone? You borrow a trick from base 10, and move over a column.

Now the second column can represent a value of two. Now with 2+1, we can count up

to three. Need to count higher than 3? Add a column. Make that column the value offour . Now we can count 4+2+1 or a grand total, of 7.

Need to see 8? Great. Add a column; call it the value of 8. Now you have 8+4+2+1 or15 in base 10. By now, you can probably guess that to go to 16, you add a column forthe value of sixteen. And the next column would be 32, and, so on.

If you go to 8 columns the column most left becomes 128 with the seventh being 64.The sixth column is the value of 32, with the fifth column holding the value of 16.

The fourth column becomes the value of 8, the third column being a placeholder for

the value of 4 with the second column having the value of 2, and the first column thevalue of 1.

If there is a zero in any co lumn , it is off , and it is not counted.

Notice that the zero has to be there, or the values in the column would all be skewedand the math wouldn't come out right.

If all the columns are on, the maximum value is equal to 128+64+32+16+8+4+2+1 or255, as shown in Table 3.

Table 3: Maximum Value of an 8-Bit Binary Number

128 64 32 16 8 4 2 1 =255

ON ON ON ON ON ON ON ON VALUE

Bit - Byte

Each on or off is called a bit. Package 8 bits together, and, it is called a byte. Becausebytes are easy to work with, you will see packaging such as 8-bit, 16-bit, 32-bit or 64-bit. If you think about how the base 10 number doubled with each move out in thecolumns, 16-bit is considerably more than 8-bits and 32-bits is a very large base 10number.

Table 4: Common Names and Sizes of Binary Numbers

Value 1 Megabyte 1 Kilobyte 32 Bits 8 Bits 4 Bits

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Equal to 1024 Kilobytes 1024 Bytes 4 Bytes 1 Byte 1 Nibble

Units = 1,024,576 Bytes8,196,608 Bits

8192 Bits1024 Octets

4 Octets4 Characters

8 Nibbles

1 Octet1 Character2 Nibbles

½ Byte½ Character

Take a piece of scratch paper and play with the base 2 columns until you are familiarwith this concept. When you are done, congratulate yourself. You have just masteredbinary math. With this mastered, you can take the hex out of hexadecimal math, seennext.

Hexadecimal (Base 16) (Page 1 of 2)

Although binary is the way computers communicate on an electronic level, dealing withlong strings of ones and zeros is too difficult a task for most human beings. Howeverbecause of the large numbers that are dealt with in computers, this makes Base10 mathunpractical as well. A new form of represent numbers was created based on using 0-9then, A-F.

The first rule to know about hexadecimal math is that a Base16 digit represents fourbinary bits.

This makes easy for programmers to represent a byte with two hexadecimal digits.Refer to the chart below to see how Base16 digits are represented in Base10, and

Base2.

Table 5: Decimal, Binary and Hexadecimal Equivalents

Base 10(Decimal)

Base 2(Binary

Base 16(Hexadecimal)

0 0000 0

1 0001 1

2 0010 2

3 0011 3

4 0100 4

5 0101 5

6 0110 6


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7 0111 7

8 1000 8

9 1001 9

10 1010 A

11 1011 B

12 1100 C

13 1101 D

14 1110 E

15 1111 F

Hexadecimal (Base 16) (Page 2 of 2)

Hexadecimal to Binary Conv ers ion

To convert a Base16 number into its binary equivalent, simply convert each Base16digit into its 4-bit binary equivalent, and then add up the value of the 1bits.Remember, all four bits must be used even if the binary number begins with zeros.Follow the example below to understand this conversion better.

As you can see, so long as you can convert a Base16 number into its binaryequivalent and then add up the base 10 numbers that the 1-bits represent, you caneasily convert any Base16 number into its Base10 equivalent.

A Hex Shor tcut

Of course we could let you go away from hexadecimal math without showingyou a quicker way of doing base 16 to base 10 convers ions . This methodrequires a bit more understanding of exponents. As you learned about

binary math, each column that binary number represents from right to left increases

in value by power of 2. Therefore the first column represents 2^0, or 1. The nextcolumn represents 2^1, or 2. The column after that represents 2^2, or 4. The samekind of "conversion chart" can be made with Base 16. Instead of using powers of 2,we will instead use powers of 16. Building our chart from right to left our first column would have a value of 16 ^0, or 1. Our next column would have a value of 16 ^1, or16. Our third column would have a value of 16^2, or 256. Refer to the charts to seehow this should be constructed.


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To perform a conversion, we start with a blank hex conversion chart, like Table 6. Base10 values are shown in ( ) for each place column.

Table 6: Blank Hexadecimal Conversion Chart

Place 16^3 (4096) 16^2 (256) 16^1 (16) 16^0 (1)

Value

For example, if we needed to convert the Base 16 number CC3Fh into Base 10, wewould begin by placing each digit into the chart from right to left, as shown in Table 7.

Table 7: Conversion of Hexadecimal Value CC3F

Place 16^3 (4096) 16^2 (256) 16^1 (16) 16^0 (1)

Value C C 3 F

Now, we multiply each digit‟s Base 10 value by its Base 16 column value, then add theresults, like so:

(12 x 4096) + (12 x 256) + (3 x 16) + (15 x 1) = 52,287

The Trick Exp lained

Now, to convert a hexadecimal number we simply place our digits startingfrom right then moving to the left. We then use the same method that welearn about in binary math. This time we will take the base 10 values of the

digits and multiply by the value of the column. You then add up all of these values. And Viola‟! You have the Base10 equivalent of your Base16 number .

VII Chapter 0000: Summary

In this chapter, you saw the beginnings of IBM, and the birth of the PC with MITS and

its Altair . It was revealed to you how Apple thought they had a better idea and thebackground of other key players and how they affect the PC today. You learned thehistory of each major expansion bus and how to Identify them.

The concepts of electricity were examined along with common electroniccomponents. Finally, you learned how to work with Base 2 and Base 10 math, with therelationship to Base 10 math, that is part of daily life.

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VIII Chapter 0000: Test for Success Questions

(Click here to see answers with explanations.)

1. Which PC, or microcomputer, did MITS develop?

A. Tandy

B. Altair

C. 386 DX

D. None of the above

2. True or False: A Conductor, in electrical terms, is an element that gives up electronsrather easily.

A. True

B. False

3. Of the examples given which are conductive materials (choose all that apply)?

A. Aluminum

B. Gold

C. Iron

D. Your finger

E. All of the above

4. Which of the following are insulators?

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8. Which of the following is How North American Electricity is delivered?

A. 120 VAC at 40 CPS

B. 240 VAC at 50 CPS

C. 120 VAC at 60 CPS

D. 240 VAC at 70 CPS

9. Taking DC Current and pulsing it is the basis for what kind of signal?

A. Analog

B. Satellite

C. Digital

D. RADAR

10. The color rings on a resistor signify what?

A. How many ohms it can resist

B. The amount of current going through it

C. Nothing. They are just there to make it look marketable

D. The amount of pressure it can sustain

11. What is the main function of a transistor?


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A. To stop the flow of electricity

B. To regulate the amount of electricity flowing through it

C. To direct the electricity where to go

D. To measure the electricity in volts

12. True or false: a capacitor stores electrons?

A. True

B. False

13. In Computer math, including Base 2; 10; and 16, is 0 a valid number?

A. Yes

B. No

14. What are the different digits available to use in base 2?

A. 0, 1

B. 1,2

C. A, B

D. 10, 16

15. In Binary, what does the number 1101 stand for?


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A. 3

B. One thousand one hundred one

C. 13

D. 32

16. What are the different digits available in hexadecimal math?

A. 1-16

B. A-P

C. 0-9 and A-F

D. 0-15

17. How many bits to a byte?

A. 1

B. 4

C. 8

D. 256

18. What does the Hexadecimal number 220h stand for in Base 10?

A. 220

B. 512

C. 544


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D. 666

19. True or false the jumper sleeve has a piece of metal inside that completes a circuitso that electricity knows where to go?

A. True

B. False

20. What do DIP Switches do?

A. They tell Electricity where to go using multiple on/off switches

B. They are used to help People learn binary math

C. They have no function

D. They connect two or more electronic posts together

IX Chapter 0000: Test for Success Answers

1. Which PC, or microcomputer, did MITS develop?

A. Tandy

B. Altair

C. 386 DX

D. None of the above

Explanation: MITS, stationed in Albuquerque, NM created the Altair. Microsoftdeveloped the code to make it work.


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2. True or False: A Conductor, in electrical terms, is an element that gives up electronsrather easily.

A. True

B. False

Explanation: Conductors give up electrons easily, which allows electricity to flowthrough them.

3. Of the examples given which are conductive materials (choose all that apply)?

A. Aluminum

B. Gold

C. Iron

D. Your finger

E. Al l of the above

Explanation: All metals conduct to some degree. You finger conducts due to the water,carbon, and iron in your blood.

4. Which of the following are insulators?

A. Rubber

B. Glass

C. Plastic

D. Al l of the above

E. None of the above

Explanation: Non-metallic materials insulate well.


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5. What does the symbol stand for?

A. Ohms

B. Volts

C. Watts

D. Megahertz

6. Which of the following is used for measuring electrical pressure?

A. Wattage

B. Vol tage

C. Ohms

D. Hertz

7. True or False: If electricity moves only one-way it is called Direct Current?

A. True

B. False

Explanation: All electricity moves towards the path of least resistance.

8. Which of the following is How North American Electricity is delivered?

A. 120 VAC at 40 CPS


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B. 240 VAC at 50 CPS

C. 120 VAC at 60 CPS

D. 240 VAC at 70 CPS

9. Taking DC Current and pulsing it is the basis for what kind of signal?

A. Analog

B. Satellite

C. Digital

D. RADAR

Explanation: Taking DC current, which has a constant voltage, and pulsing it creates1‟s and 0‟s for binary counting.

10. The color rings on a resistor signify what?

A. How many ohms i t can res is t

B. The amount of current going through it

C. Nothing. They are just there to make it look marketable

D. The amount of pressure it can sustain

Explanation: The rings signify the amount of resistance the resistor has, measured inohms.

11. What is the main function of a transistor?

A. To stop the flow of electricity


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B. To regulate the amo unt of electr ic i ty f lowing thro ugh i t

C. To direct the electricity where to go

D. To measure the electricity in volts

Explanation: Remember the analogy that transistors are like valves for electricity. Theyregulate flow.

12. True or false: a capacitor stores electrons?

A. True

B. False

Explanation: Capacitors are like water tanks that store electricity.

13. In Computer math, including Base 2; 10; and 16, is 0 a valid number?

A. Yes

B. No

Explanation: Zero is always a valid number.

14. What are the different digits available to use in base 2?

A. 0, 1

B. 1,2

C. A, B

D. 10, 16


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15. In Binary, what does the number 1101 stand for?

A. 3

B. One thousand one hundred one

C. 13

D. 32

Explanation: Count up the columns. 8+4+1=13.

16. What are the different digits available in hexadecimal math?

A. 1-16

B. A-P

C. 0-9 and A-F

D. 0-15

17. How many bits to a byte?

A. 1

B. 4

C. 8

D. 256

Explanation: There are 8 bits in a byte, 4 bits in a nibble. No kidding.


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18. What does the Hexadecimal number 220h stand for in Base 10?

A. 220

B. 512

C. 544

D. 666

Explanation: Refer to your Base2 and Base16 charts.

19. True or false the jumper sleeve has a piece of metal inside that completes a circuitso that electricity knows where to go?

A. True

B. False

Explanation: Jumpers complete an electronic circuit when they are placed over twometal posts.

20. What do DIP Switches do?

A. They tel l Electr ic i ty where to go using mu l t ip le on/of f sw i tches

B. They are used to help People learn binary math

C. They have no function

D. They connect two or more electronic posts together

Explanation: DIP switches can be thought of as banks of jumpers in switch form.


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Chapter 0001: Power Supplies - System Board

"If you have no will to change it, you have no right to criticize it."-- Anonymous

Chapter Objectives

The objective of this chapter is to provide the reader with an understanding of thefollowing:

1.1 Identify basic terms, concepts, and functions of system modules, including howeach module should work during normal operation and during the boot process:

System Board; Power Supply; Firmware; CMOS

1.2 Identify basic procedures for adding removing field replaceable modules for bothdesktop and portable systems:

System Board; Power Supply

1.3 Identify available IRQs, DMAs, and I/O addresses and procedures for deviceinstallation and configuration:

Standard IRQ settings; Hexadecimal/addresses

1.8 Identifies hardware methods of upgrading system performance, procedures forreplacing the basic subsystem components, unique components and when to use them:

Memory; CPU; Upgrading BIOS; When to upgrade BIOS

2.1 Identify common symptoms and problems associated with each module and have totroubleshoot and isolate the problems:

Processor/memory; Motherboards; BIOS; CMOS

Power supply; POST audible/visual error codes

2.2 Identify basic troubleshooting procedures and how to elicit problem symptoms fromcustomers:

Troubleshooting/isolation problems determination procedures

Determine whether hardware or software problem


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Symptoms/error codes and situations when the problem occurred

4.1 Distinguish between popular CPU chips in terms of their basic characteristics.

Popular CPU chips (Intel, AMD, Cyrix)

Sockets; (SEC) single edge contact

4.3 Identify the most popular types of motherboards, the components and architecture(bus structures and power supplies):

Types of motherboards: AT (full and baby); ATX

Bus architecture: ISA; PCI; AGP; USB (Universal serial bus); VESA localbus (VL-bus)

4.4 Identify the purpose of CMOS (complementary metal-oxide semiconductor), what itcontains and how to change its basic parameters:

Boot sequence; Date/Time; Plug & play BIOS

Gett ing Ready - Quest ions

1. The Pentium IV uses _______ RAM.

2. Athlon uses a ______ to connect the CPU

3. Slot 1 supports the __________, __________, and __________ CPU.

4. Slot 1 uses a ___________ _________ __________.

5. The Pentium III introduced ____.


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Gett ing Ready - An swers

1. RAMBUS

2. Slot A

3. Celeron, Pentium II, Pentium III

4. Single Edge Connector

5. SIMD

I Introduction to Chapter 0001

The first few pages of this chapter are historical in nature, and not required for the A+Core. However, the information contained here will create a perspective ofunderstanding both legacy equipment as well as where we are in current technology.Few sub systems in the PC have gone through the changes as quickly as the CPU.

II The Relationship Between Power Supplies and System

Boards

At first glance, it may seem odd to discuss power supplies and system boards in thesame chapter. In fact, the two are closely related, because power supplies are theenergy source for the computer. You will see the choices between different designsimpacting the system board and the form factor.

It will become clear how the ch ipset impacts the size of the system board along withother factors.

The dance between the BIOS interacting with the CMOS to create a POST routine willbe revealed. You will discover how to upgrade BIOS that is not capable of meeting yourneeds.

Further details about various expansion buses and the impact of the choices you canmake will become clear.

The sometimes-disastrous interaction with drivers will be demystified so you maybecome a driver magician.


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Various levels of cache and the interaction between them and how they affectperformance will guide you though an area frequently fraught with inaccuracy, thusgiving a clear understanding to utilize to your benefit.

The ability to improve performance by properly applying techniques such as Bus

Master ing and DMA will be explained.

Confusing issues such as PCI Steering and Memory mapping are explained. So let‟sget started.

III Power Supplies

The term power supply in the PC is actually a bit of a misnomer. Today‟s power supplyis a sealed box, with a cool ing fan and pow er leads . Inside the power supply box is as tep down t rans former that converts 120 or 240 volts AC to approximately 12 and 5 volts AC. From this point, the AC voltage is run through four diodes filtering off the

negative voltage. This is known as a br idge rect i f ier . Newer power supplies useswitching transformers in place of the diodes to accomplish this. They are known asswitching power supplies.

From there, the power is passed to a capaci tor , which outputs clean DC power .Inside the case of the power supply are only two more parts. They are a fuse and afan. The fan is used to pull air through the computer case as well as to coolcomponents of the power supply itself.


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Figure 18: How power is converted from household current to 5 and 12 Volts DC.

Voltage steps down from transformer on the left to 12 Volts AC, then the fourdiodes in the center (the diamond shape) convert to positive only voltage. The --|(-- is the symbol for the capacitor that filters the AC ripple to straight DC voltage.

The same process occurs for the 5 Volts.

(Actually, the modern PC power supply is actually a switched power supply. Seehttp: / /www.smp stech.com/tutor ia l /t01int .htm#SMPSDEF for details. The processdescribed above is still popular with “wall warts” used for telephones, small CD

http://www.smpstech.com/tutorial/t01int.htm#SMPSDEFhttp://www.smpstech.com/tutorial/t01int.htm#SMPSDEFhttp://www.smpstech.com/tutorial/t01int.htm#SMPSDEF


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players, etc.)

IV Power Supply Form Factors

Regardless of the type of PC computer, these components are there. What makes

power supplies different is the actual form factor or design that contains thesecomponents. There are two major types of form factors for power supplies, AT and ATX.

AT Power Supply

The first common form factor is known as an AT power supply. Two features distinguish the AT power supply from its relative. An AT power supply has amechanical switch used to control the availability of AC power .

The second feature that makes an AT power supply instantly recognizable has thepower connectors for the motherboard, sometimes called a system board. An AT

power supply has two power connectors for the motherboard - labeled P8 and P9.

Figure 19: Understanding the Connections. I is power for a 3.5” floppy drive and II


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is power for a 3.5” hard drive. III is the mechanical switch. Two connections forpower with the AT motherboard are P8 indicated with IV, with P9 designated by V.

P8 & P9 Groun ds

When connecting the power supply to the motherboard, make sure the blackground leads are side by side. This insures P8 & P9 are properly arranged.

Computer manufacturers faced one challenge when working with the AT power supply. Remember the fact that the AT power supply uses a mechanical switch tosupply power. That makes it impossible to turn the computer on remotely. Toaccomplish remote power -on, a small redesign on the power supply was needed.That redesign is found in the ATX power supply.

AT is not A TX

Since the AT and ATX designs have different power connectors and caseconfiguration they are not interchangeable.

ATX Power Supply

The ATX power supply has a small power lead going to the case and the switch is

used as a signaling device to turn the computer power supply on or off . By using signaling, other signals may be installed in the computer such as on a NetworkInterface Card (NIC).

This feature is marketed under the handle Wake On LAN (WOL). This makes itpossible for a network administrator to wake up an entire office full of computers,download updates, for example a new version of word processor.

This saves considerable labor because the administrator did not have to visit eachPC. Further, productivity is not lost because computers are upgraded whenworkers were at home. And users don't have the frustration of incompatible file formats

between two different versions of software.


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Figure 20: ATX power connectors. The large single connector and thin wires forpower switching Identify an ATX power supply. I is the lead for the power on/off

control. II is the ATX systemboard power connector. III is a 5.25” drive powerconnector with a 3.5” drive power connector in parallel to the right.

ATX Form Factor

The ATX Form Factor allows shutting down the computer using software.

Another feature of the ATX power supply is there's only one connector for the power ,making it impossible to reverse the leads as can be done with P8 and P9 on an ATpower supply.


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Of course differences in how the power switch operates means a different computer case must be used. With the rationale of the two different power supplies,cases are known as AT or ATX cases.

That isn't the only difference. You just learned the connectors between the two power

supplies are different. That means the systemboard must be mated to accept thecorrect type of power connector .

Figure 21: AT & ATX connections. For a brief period of time, some system boardsoffered AT (top) and ATX (below) connections.

Today, virtually all new computer cases, power supplies and system boards areATX based. And that doesn't mean the Pentium computer that just blew a power supplyis going to use an ATX power supply. If you are going to do any fieldwork, and you arenot positive about which power supply resides in an ailing computer, take along bothtypes of power supplies.

V System Board Form Factors

As with power supplies, each system board design layout is known as a form factor .While not all computer systems fit the categories listed below, most do. Starting with thelargest design, it is time to examine the AT.

Depending on the case design, several different form factors may be used whencreating a system board. In late 1984, IBM released the PC- AT, featuring an 80286CPU. Because of all the electronics involved, the system board was BIG, over a square


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foot of systemboard. The original AT power supply had inverted L- shape toaccommodate space for the system board.

Baby AT Form Factor

By about 1997 electronics had shrunk in both size and heat output so the original ATform factor was no longer needed. Anytime a manufacturer can use fewer rawmaterials, they do so, to reduce costs. The newer smaller form factor was called theBaby AT form factor. The footprint of the Baby AT is usually about 8.5" x 13". This is abit smaller than the original 12" x 13" AT form factor.

ATX Form Factor

Today the ATX design reigns. The change is not so much about square inches. It isabout how the square inches are laid out. The orientation on the systemboard is

rotated 90 degrees. Cable connections for drives are closer to the part of the case where the drives are usually mounted, and the CPU is closer to the power supply,and therefore the cooling fan.

NLX Form Factor

In some situations, such as replacing a cash register with a computer to create aPoint Of Sale (POS) system, space is at a premium. In these situations may call for asystem board with no CPU on it. Instead all electronics are placed on cards with thesystem board be nothing more than a passive backplane. This also allows forsimplified repair and upgrade ability.

With the physical description of what is inside the case complete for this chapter, it istime to review the components of the system board.

VI Chipsets

Recall in Chapter 0000 how IBM quickly got the IBM PC ready for market. Thecompany used almost entirely, 'off-the-shelf ' electronic components. Major parts ofthe system board were consumed by purchasing a standard component known asTransistor-to-Transistor Logic (TTL). IBM arranged these TTLs on the system board

to create a computer in very little time.

One inventive company looked at all the real estate on the system board being usedby the TTL‟s. They engineered the exact same circuit design, and put the TTL‟s,resistors, capacitors and transistors into five different IC's. With this stroke ofbrilliance, hundreds of components were reduced to five. This may be the mostpopular form of IC in use today. This type of IC is known as an Application SpecificIntegrated Circuit (ASIC).


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Figure 22: One of the first chipsets (from Suntac) was created to replace thediscrete components found on the IBM AT.

Prior the to ASIC, ICs were designed to perform a specific function, in a verygeneric manner . For example, the 555 IC was a clock chip. But it was not specificallybuilt to power a jumbo digital clock, with alarm, complete with the electronics to drive adisplay. An ASIC would have the 555 design along with the necessary electronics todrive display and a alarm buzzer.

As computer requirements became more sophisticated, the ASIC grew more complex,and the number of chips needs became less. The chipset of 5 chips became one chip.Today two chips not only control the computer , they can have features that used to require expansion cards be added into the computer. For example, on-board sound is now a common feature in a chipset.

As time has marched forward, the chipset has been reduced in count, dropping toeither 2 chips or even the minimum count of 1 chip.

Northbridge

The first of the two chips that make up the chipset of a motherboard is called theNorthbridge. The Northbridge handles data buses, cache controllers, system buses and CPU memory.


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Due to the nature of rapid changes in these sub-sections, Northbridge chips seeupdates more frequently than it companion, the Southbridge.

Southbridge

The Southbridge handles peripherals such as printer ports and drive controllers.While there are advances in these areas, they do not happen as quickly as the fluidstate of the Northbridge.

Because it is possible to have changes occur more quickly in the Northbridge the nameflag for the chipset resides with the Northbridge side.

Technically, it is even possible to have two different chip makers between theNorthbridge and Southbridge. Different names you may run into include: Intel, AMD,SiS and VIA. This sampling is by no means exhaustive however these makers arepopular today.

You and I cannot do too much configuration to a chipset. The most we get to do isturn the on-board sound on or off, and other small things. In our next section weexamine something really configurable.

Pick you r Chipset Careful ly

A few decades of experience help put things in perspective. Sometimes, I'msurprised. In this section, what has surprised me greatly is how a chipsetmakes or breaks system

chapter system computer

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