a+essential

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What is a computer?

Computer is a General purpose machine, commonly consisting of digital

circuitry, that accepts (inputs), stores, manipulates, and generates (outputs)

data as numbers, text, graphics, voice, video files, or electrical signals, inaccordance with instructions called a program.

History of computer:-

The first electronic digital computers were developed in the mid-20th century

(1940 – 1945). Originally, they were the size of a large room, consuming as much

power as several hundred modern personal computers (PCs).

Generation of Computer:-

First Generation (1940-1956) Vacuum Tubes:-The first computers used

vacuum tubes for circuitry and magnetic drums for memory, and were often

enormous, taking up entire rooms. They were very expensive to operate and

in addition to using a great deal of electricity, generated a lot of heat, which

was often the cause of malfunctions.

Second Generation (1956-1963) Transistors:-Transistors replaced vacuum

tubes and ushered in the second generation of computers. The transistor was

invented in 1947 but did not see widespread use in computers until the late

1950s. The transistor was far superior to the vacuum tube, allowing


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computers to become smaller, faster, cheaper, more energy-efficient and morereliable than their first-generation predecessors.

Third Generation (1964-1971) Integrated Circuits – The development of the

integrated circuit was the hallmark of the third generation of computers.Transistors were miniaturized and placed on silicon chips, called

semiconductors, which drastically increased the speed and efficiency of computers.


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Fourth Generation (1971-Present) Microprocessors

The microprocessor brought the fourth generation of computers, as thousands

of integrated circuits were built onto a single silicon chip. What in the first

generation filled an entire room could now fit in the palm of the hand. The

Intel 4004 chip, developed in 1971, located all the components of the

computer — from the central processing unit and memory to input/output

controls — on a single chip.


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Fifth Generation (Present and Beyond) Artificial Intelligence:-Fifth

generation computing devices, based on artificial intelligence, are still in

development, though there are some applications, such as voice recognition,

that are being used today. The use of parallel processing and superconductors

is helping to make artificial intelligence a reality. Quantum computation and

molecular and nanotechnology will radically change the face of computers in

years to come.

Types of computer:-

1. Supercomputer and Mainframe:- Supercomputer is a broad term for

one of the fastest computers currently available. Supercomputers are

very expensive and are employed for specialized applications that

require immense amounts of mathematical calculations (number

crunching). For example, weather forecasting requires a

supercomputer. Mainframe was a term originally referring to the

cabinet containing the central processor unit or "main frame" of a

room-filling Stone Age batch machine. After the emergence of smaller"minicomputer" designs in the early 1970s, the traditional big iron

machines were described as "mainframe computers" and eventually

just as mainframes.


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2. Minicomputer:- It is a midsize computer. In the past decade, the

distinction between large minicomputers and small mainframes has

blurred, however, as has the distinction between small minicomputers

and workstations. But in general, a minicomputer is a multiprocessing

system capable of supporting from up to 200 users simultaneously.

3. Workstation:- It is a type of computer used for engineering applications

(CAD/CAM), desktop publishing, software development, and other

types of applications that require a moderate amount of computing

power and relatively high quality graphics capabilities. Workstations

generally come with a large, high-resolution graphics screen, at large

amount of RAM, built-in network support, and a graphical user

interface.

4. Personal computer:- It can be defined as a small, relatively inexpensive

computer designed for an individual user. All are based on the

microprocessor technology that enables manufacturers to put an entire

CPU on one chip. Personal computers first appeared in the late 1970s.

One of the first and most popular personal computers was the Apple II,

introduced in 1977 by Apple Computer.

5. III, Personal Computer Types:- Actual personal computers can be

generally classified by size and chassis / case. The chassis or case is the


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metal frame that serves as the structural support for electronic

components.

a. Tower model :-The term refers to a computer in which the power supply,

motherboard, and mass storage devices are stacked on top of each other in acabinet. The main advantage of tower models is that there are fewer spaceconstraints, which makes installation of additional storage devices easier.

b. Desktop model:-A computer designed to fit comfortably on top of a desk,

typically with the monitor sitting on top of the computer. Desktop model

computers are broad and low, whereas tower model computers are narrow

and tall.

c. Notebook computer:-An extremely lightweight personal computer.

Notebook computers typically weigh less than 6 pounds and are small enoughto fit easily in a briefcase. Aside from size, the principal difference between a

notebook computer and a personal computer is the display screen. Notebook

computers use a variety of techniques, known as flat-panel technologies, to

produce a lightweight and non-bulky display screen. The quality of notebookdisplay screens varies considerably.

d. Laptop computer :-A small, portable computer -- small enough that it can

sit on your lap. Nowadays, laptop computers are more frequently callednotebook computers.

e. Subnotebook computer:-A portable computer that is slightly lighter and

smaller than a full-sized notebook computer. Typically, subnotebook

computers have a smaller keyboard and screen, but are otherwise equivalent

to notebook computers.

f. Hand-held computer :-A portable computer that is small enough to be held

in one’s hand. Although extremely convenient to carry, handheld computers

have not replaced notebook computers because of their small keyboards andscreens.

g. Palmtop :-A small computer that literally fits in your palm. Compared to

full-size computers, palmtops are severely limited, but they are practical for

certain functions such as phone books and calendars. Palmtops that use a pen

rather than a keyboard for input are often called hand-held computers orPDA.


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Component needed to assemble a basic modern PC system.

Motherboard

Processor

Memory (Primary)

Hard disk

CD-ROM

Floppy Drive

Keyboard

Mouse

Monitor

Power Supply

Cabinet

Motherboard :-


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Motherboard is the important component of the computer as everything else

is connected to it. And it controls everything in the system.

Motherboard are available in several different shapes.

Motherboard usually contain the following individual components:-

1) Processor slot

2) Processor voltage regulators

3) Motherboard chipset

4) Level 2 cache

5) Memory SIMM or DIMM sockets

6) Bus slots

7) ROM BIOS

8) Clock / CMOS battery

9) Super I/O chips


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Processor:-

The processor is often thought as the engine of the computer. Then the

processor reads the commands from the memory and then executes them. the

processor is one of the most expensive parts of the computers and is also oneof the smallest parts.

Primary Memory:-

Memory : Is used to hold programs and data during execution.

Primary memory is often called as RAM(Random Access Memory). It holds

all the programs and data the processor is using at a given time. RAM is

volatile because its contents are erased

when power is switched off.

Hard disk drive:-

A hard drive consists of spinning platters

made up of aluminum or ceramic that is


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coated with magnetic media. The platters

come in various sizes. This is also called

as Secondary memory. There can be

several programs in the system, which

cannot be stored in RAM, so we need a

very huge non-volatile memory, which

can be used for storing all the programs,

and data when the system is not in use

are called as Hard disks.

CD-ROM drive:-

CD-ROM stands for compact disk read only memory. It consists of smalldisks similar to the gramophone records to hold digital information. With the

advancement in technology writable CD’s are also available.

Floppy Disk Drive:-


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Floppy disks are the slowest and the smallest form of secondary storage. They

provide a simple way to carry information from one place to another, and

backup small amount of files.

Keyboard:-

The keyboard is the main input device for most computers. It is used to input

text or enter commands into the PC. Nowadays keyboards with additional

features are available like multimedia keyboard, wireless keyboard.

Mouse:-


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With the invention of graphical user interface mouse is used to input

information into the computer. Users simply point and click to enter

information. The main advantage of mouse over keyboard is simplicity.

Monitor:-

The monitor is the specialized high-resolution screen similar to a television.

The actual display screen is made up or red, green and blue dots that are

illuminated by electron beam from behind.

Power supply:-


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SMPS(Switch Mode Power Supply): The power supply supplies power to

every single part in the PC. The main function of the power supply is to

convert the 230 V AC into 3.3 V, 5 V and 12 V DC power that the systemrequires for the operations.

Cabinet:-

The box or outer shell that houses most of the computers. The cabinet actually

performs several important functions for your PC including protection to the

system components, directing cooling airflow, and allowing installation of and

access to the system components.

Peripheral Devices:-

Any external device, which is not necessary to perform the basic operation of

computer, is called as peripherals. They provide additional computing

capabilities.

For ex : Printers, Modems, Speakers etc.

Modem:-


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Modem (Modulator and Demodulator) is typically used to send digital data

over a phone line. The sending modem converts digital data into analog data,

which can be transmitted over telephone lines, and the receiving modem

converts the analog data back into digital form. This is used to connect toInternet.

A typical arrangement is shown below:-

Modems are available in different capacities.• 300 bps - 1960s through 1983 or so

• 1200 bps - Gained popularity in 1984 and 1985

• 2400 bps

• 9600 bps - First appeared in late 1990 and early 1991

• 19.2 kilobits per second (Kbps)

• 28.8 Kbps

• 33.6 Kbps

• 56 Kbps - Became the standard in 1998

10 Computer Hardware

• ADSL, with theoretical maximum of up to 8 megabits per second (Mbps)- Gained popularity in 1999

Printers:-


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Operating System

pretty much any computer part you buy will come with drivers for most recent

versions of Windows (but check the box anyway, just to make sure).

Consider a Kit

If you've never built a computer before, you may want to consider a computer kit.

Kits come with pre-selected parts that (usually) have been tested to work with each

other. They usually also include fairly detailed assembly instructions.

Compatibility

If you decide to design your computer yourself check the newsgroups and

message boards to see if anyone's had problems with the particular combinationsyou've selected. Some components simply don't play nicely with each other.

While you're fantasizing about all of those great parts you want to put in your new

computer, let's look at the tools that you'll need.

Assembling your own PC: Getting Ready

Before beginning to assemble your new computer, gather everything you need

(your computer, components and manuals) together in one place.

Tools You Need to Build Your Own Computer

You don't need an expensive toolkit to build your own computer, but there are a

few simple tools that you absolutely must have. All of these can be easily obtained

at almost any computer store or online, usually in a little case that contains

everything you need. You can also buy most of them at ordinary hardware stores.

As with all tools, you should buy the best quality computer tools that you can

afford. Good tools last longer and make the job easier. All computer tools should

be non-magnetized.

You will need, at a minimum, the following simple tools:


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Screwdrivers and nut drivers.

You should have available, at a minimum, small- and medium-sized Phillips and

flat screwdrivers and a 1/4" nut driver.

Needle-Nosed Pliers

Very small needle-nosed pliers are very handy for removing and inserting jumpers

on motherboards and hard drives. (A pair of tweezers or surgical forceps alsoworks well for this purpose.)

Cable Ties

Plastic cable ties are useful for neatly bundling wires and cables away from fans

and other components inside the computer. If you can't find them, electrical tape is

an acceptable substitute.

Anti-Static Wrist Strap

This is a little elastic strap connected to a wire with an alligator clip on the other

end. The alligator clip is attached to a metal part of the computer chassis, and the

elastic band slipped around your wrist.


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Heat Sink Compound

This is usually included with processor fans, but may be purchased separately. It is

applied neatly to the area where the processor contacts the heat sink to improve

cooling efficiency. (Some heat sinks have the compound "built-in" behind a little

peel-off label.) I like Arctic Silver.

Pill Bottle

You'll need a pill bottle or other small container to hold the various screws,

jumpers, and other small parts used to assemble and configure a homebuilt

computer.

Choosing a Computer Case and Power Supply

It may not seem too exciting, but selecting a case for your homebuilt computer is

one of the most important steps in the planning process. The case you select will

determine what form factor motherboard you will need, how many drives you can

install, and many other things.

Choosing a case wisely can save you many hours of annoyance and expense later

on. Here are some of the things you should consider:

Form Factor

The form factor is the first thing you must consider when selecting a case for your

new computer. The most common form factors as of this writing are still ATX and

micro-ATX, which differ mainly in their size. They are electronically identical.

Number of Drive Bays

Another important factor affecting the size of case you choose is the

number of drives you plan to install. Almost all PC cases haveinternal bays for at least one hard drive, and front-accessible bays

for at least one optical drive (CD-ROM, CD-RW, DVD-ROM, or

DVD-RW) and a floppy drive.


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Power Supply

Power supplies are usually (but not always) included and pre-installed in computer

cases. But sometimes a perfectly good case may come with a crappy power supply

— and the power supply is not a part you want to skimp on. A bad power supply

can fry your whole system. In fact, sometimes I find a computer case that I like,

but which comes with a power supply that I don't; so I just remove the included

power supply and install a better one.

Make sure the power supply you use is of high quality and is adequate for yourneeds and has the correct connectors for the type of system you are building.

The following are our minimum power supply recommendations based on the

combined number of drives (floppy, optical, tape, and hard drives) in a Pentium D,

Core2 Duo, or Athlon 64 X2 system:

• Three drives: 400 Watts

• Four or five drives: 500 Watts

• Six to eight drives: 650 Watts

• More than that: You really should consider dual power supplies.

Also remember that many USB and Firewire devices draw their power from the

computer's power supply, so you'll want to leave plenty of headroom when

calculating wattage requirements.

Cooling

Excess heat is one of your computer's worst enemies. Select a case that has at least

one place to mount a chassis fan. Without a chassis fan, the heat thrown by the

power supply fan, CPU fan, chipset fan, and video card fan will rapidly raise the

temperature inside the case. A simple case fan will help bleed this heat off and

keep your computer cool and happy.


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Ease of Assembly and Maintenance

Finally, when selecting a computer case, consider how the case design will affect

the ease of assembling and maintaining the computer. Look at things such as how

easy the case is to open and whether the drive cages are easily removable (which

makes drive installation and replacement easier).

Installing the Motherboard in your Computer

Installing the motherboard in your homebuilt computer usually is pretty easy

(though sometimes knuckle-busting). Basically, you just line up the board with the

mounting holes and rear-panel openings, and then screw it in.

Read the Manual!

Before actually installing the motherboard, be sure to

thoroughly read the motherboard manual (that's that

paper thing that came in the box) to familiarize

yourself with the board's layout and connections, to

make absolutely sure that it is compatible with the

processor and RAM that you will be using, to make

sure that the jumper settings, if any, are correct, and to check for any otherwarnings or instructions.

Determine Which Mounting Holes You will be

Using

About the only difficult part of installing a

motherboard is matching up the mounting holes in themobo with the ones on the case.

In theory, the mounting hole locations are standardized

within a given form factor; but in practice, it's a rare thing to find a case and

motherboard whose mounting holes exactly correspond. More often, you will have

to look at the mounting holes in the motherboard to determine which mountingholes on the case you will be using.


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Installing the Standoffs

Once you have determined which mounting holes you

will be using, you will need to insert standoffs in the

corresponding holes in the computer case. Chances are

that some of them will already be installed, and you

will have to install the rest.

There are several types of standoffs, with the ones on

the right being the most common. The purpose of standoffs is to separate the back

of the motherboard from the metal case. You install the standoffs in the mounting

holes in the case that correspond to the holes in your motherboard.

If you don't install the standoffs, then you will most likely damage your

motherboard when you try to install it.

Finally, don't over-tighten the standoffs. Hand-tight plus a smidgen is enough.

Most cases are made of thin metal that can strip if you over-tighten the standoffs.

Install the Motherboard

Once you have the correct standoffs inserted, lay themotherboard into the case, line up the mounting holesand the rear-panel connectors, and screw it down.

Usually, the easiest way to install a motherboard is to

lay the motherboard over the standoffs slightly forward

of the rear panel connectors, then slide it back into the rear panel connectors until

the mounting holes line up. Make sure that you're not snagging any wires, thenscrew the board down.

Don't over tighten-the screws! You will crack the motherboard if you do, and thenit will be useless! The screws should be snug, not excessively tight. Use a standardscrewdriver, not an electric one. This is delicate stuff we're doing here.


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Attach the Power Connectors

Finally, connect the ATX power connector from the

power supply to the motherboard. Do this now. If you

forget about it and later fire up your computer while

the ATX connector is not connected to anything, then

you will fry your computer's power supply.

Installing the Processor in Your Computer

The microprocessor is often both the most delicate and the most expensive part of

a homebuilt computer. As such, it deserves and requires special care. Handle

processors gingerly, and never touch the pins or conductors with your fingers.

Anti-Static Precautions

Processors are extremely sensitive to static charges and

physical shock. A static charge that's too small for a

human being to even feel can completely destroy a

processor. In addition, processors can be damaged byrough handling or being dropped.

So never handle a processor roughly, never touch the pins, and never handle itunless you are using proper anti-static precautions.

Handle the processor carefully, holding it only by the edges. Set it down only on an

anti-static mat or on the foam pad that it was shipped in. Be kind to your processor,and your processor will be kind to you.

Factors Affecting CPU Performance

There are several factors that affect processor performance. Understanding these

factors will help you make the proper choices when designing your homebuiltcomputer.

The most important factors affecting processor performance are:


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Instruction Set

This is the processor's built-in code that tells it how to execute its duties.

You really have no control over the instruction set. It is built-in to the CPU. But

together with processor architecture, it does affect performance across a given lineof CPU's; and so it is mentioned here just for the sake of accuracy.

Clock Speed

The clock speed is stated in megahertz (MHz) or gigahertz (GHz), and is a measure

of how many instructions the processor can execute in one second.

Bandwidth

Measured in bits, the bandwidth determines how much information the processor

can process in one instruction. If you were to compare data flow to the flow of

traffic on a highway, then clock speed would be the speed limit, and bandwidth

would be the number of lanes on the highway.

Front Side Bus (FSB) Speed

The FSB is the interface between the processor and the system memory. As such,

the FSB speed limits the rate at which data can get to the CPU, which in turn limits

the rate at which the CPU can process that data. The CPU's FSB speed determinesthe maximum speed at which it can transfer data to the rest of the system.

Other factors affecting data transfer rates include the system clock speed, themotherboard chipset, and the RAM speed.

On-Board Level-2 (L2) Cache

The on-board (or "on-die") cache is a little bit of high-performance RAM built

directly into the processor. It enables the CPU to access repeatedly used data

directly from its own on-board memory, rather than repeatedly requesting it from

the system RAM. L2 Cache is very critical to applications such as games, video

editing, and 3-D applications such as CAD/CAM programs. It's less important foractivities such as web surfing, email, and word processing.

Most low-cost CPU's have as little as 128K of L2 cache. Higher-end CPU's have

up to 4 MB.


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Heat and Heat Dissipation

When processors run too hot, they can start doing funky things like cause errors,

lock, freeze, or even burn up. Installing an inadequate cooling system can cause

your homebuilt computer project to go sour in a big (and possibly expensive) way.

So don't skimp on the cooling.

Choosing a CPU

Choosing a CPU for your homebuilt computer is probably one of the first things

you will want to do during the planning stage. When choosing a CPU for a

desktop, there are several factors to consider. The most important of these are

speed, form factor, architecture, L2 cache, and reputation. Increasingly, computer

builders are also concerned about power consumption and energy conservation.

CPU Speed

The speed of a CPU determines how many computations it can perform per

second. Obviously, a faster chip can perform more computations. If you plan to use

your computer for pretty routine, low-resource applications like surfing the web,

word processing, and checking email, you can save yourself some money by

buying a chip in the 4,000 MHz neighborhood.

Form Factor

The form factor of a CPU refers to several things, most important of which for the

do-it-yourself computer builder is what socket it fits. You must purchase a

motherboard that supports your processor's form factor.

Architecture

Architecture refers to such things as the number of cores, the bandwidth, and the

chip's internal circuitry. In general, multi-core processors outperform single-coreprocessors, and some CPUs have internal circuitry that makes them perform better

than other chips running at the same clock speed.

L2 Cache


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The L2 (or Level 2) cache bridges the gap between the very fast CPU and the

much slower system RAM bus (and the even slower hard drive) by anticipating

and storing data right on the CPU itself. This dramatically increases performance at

a given clock speed. With L2 cache, more is always better. Look for a chip with at

least 1 MB of L2 cache per core. Although this significantly increases the cost of the CPU, it's worth the investment.

Reputation

As with any major purchase, do your homework before buying. Check Internet

message boards to see how satisfied other users have been with the chips you are

considering, and read the reviews often posted on retailers' sites.

64-Bit CPU's

Once upon a time, this page included a discussion about 32-bit CPUs. From

feedback I've received, it seems that practically no one is interested in building 32-

bit machines anymore, so I've decided to discuss only 64-bit chips.

AMD 64-bit Chips

As of this revision, 64-bit processors have pretty much become the norm. Among

the most popular among do-it-yourself computer builders are AMD's Athlon64 series.

Because all new operating system and application releases are expected to require

or be optimized for 64-bit within the next year or so, it doesn't seem to make muchsense not to choose 64-bit for your computer-building project.

Intel 64-bit Chips

AMD actually led the pack in the development of 64-bit processors, leaving Intel

in the unfamiliar position of having to play catch-up. But catch up they did, with adazzling selection of multi-core 64-bit chips with generous amounts of L2 cache.

These chips, of which the Core2 Quad is my personal favorite, have quickly gained

a reputation for speed, stability, and durability.


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something called "heat sink compound" or "thermal jelly," which is applied

between the heat sink and the die of the processor to improve heat transfer from the

processor to the heat sink.

If your heat sink doesn't have pre-applied compound,

you will need to apply a thin coating of heat sink

compound directly to the processor die. This also

applies if, for some reason, you have removed and are

replacing the heat sink.

Mounting the CPU Cooler

The CPU cooler assembly is positioned over the

processor and is usually secured to the motherboard by

metal clips that hold the heat sink down tightly againstthe processor.

Notice that on bail-type sockets, both the socket and

the heat sink are offset from center a little to accommodate the bail. Make sure you

install the cooler with its offset on the same side as the offset on the socket.

Use a slotted screwdriver to gently, but firmly, hook the retaining clips under the

tabs on the processor socket. Be very careful not to let the screwdriver slip. If it

scratches the surface of the motherboard, the mobo

could be ruined.

Don't forget to plug in the fan! In most cases, it will

plug into a three-pin connector on the motherboard that

is (appropriately enough) labeled "CPU Fan" in teensy-

weensy letters.

Chipset Coolers

Most modern motherboards also have a chipset cooler,

at least on the Northbridge chipset. These are almost always factory-installed and

are adequate for all but the most spinning or starts making noises.


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Installing the RAM (Memory) Modules

Random Access Memory

What is RAM?

Simply stated, Random Access Memory is a name

applied to microchips designed to store and address

information while a computer is actually using it.

RAM is volatile, which means that it needs a constant

current in order for it to retain information. Once the current is removed, the

information disappears. This is why you have to save a document that you're

working on before you shut off your computer. When you hit "save," the documentis transferred from the RAM (temporary storage), to permanent storage (hard drive,

floppy disk, CD-RW, etc.).

Types of RAM

RAM comes in different types and flavors to suit different needs and budgets.

There are many specialized types of RAM, but some of the more common

types are:

•

SRAM. Static Random Access Memory is very fast and very expensive. It isprimarily used for memory caching (such as on processor chips).

Architecturally, it has multiple transistors for each memory cell. It does not

need to be refreshed. It is rarely encountered except as a component of other

devices.

• DRAM. Dynamic Random Access Memory is slower than SRAM and needs

to be refreshed many times every second. Each memory cell consists of a

capacitor and a transistor. DRAM is much less expensive than SRAM.

• SDRAM. Synchronous Dynamic Random Access Memory is a special type

of DRAM that is synchronized to the system clock. Each chip contains

internal registers that accept requests from the CPU, thus freeing the CPU to

do other things while the data is assembled.

• DDR-SDRAM. Double-Data Rate SDRAM works the same way as does

ordinary SDRAM, except it works twice as quickly by synchronizing to both

the rising and falling of the clock pulse (which makes it twice as fast as

ordinary SDRAM). DDR-SDRAM can also be installed in dual-channels if


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the motherboard supports this arrangement. There is no difference in the

actual RAM modules used for dual-channel DDR, but the two sticks of

RAM in each channel must be a matched pair (same size and speed). DDR3

is the latest evolution in DDR RAM.

• RDRAM. RAMBUS Dynamic Random Access Memory is a very fast type

of RAM in which the chips work in parallel to produce very fast speeds.

However, because it is proprietary and very expensive, RDRAM has beenslow in catching on.

Pictures of Selected RAM Form Factors

SIMM (Single-Inline Memory

Module).Used mainly in oldercomputers; now considered obsolete.

Its contacts were along only one face

of the edge, hence the word "single."

DIMM (Dual-Inline Memory

Module).The most common RAM

form factor in use today.

SDRAM and DDR-SDRAM are

examples of two types of RAM

using the DIMM form factor.

SO-DIMM (Small-Outline Dual-Inline Memory

Module).Used primarily in laptop computers and other

compact computing devices.


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Choosing RAM

What type of RAM Should I Choose?

You must decide what type of RAM your homebuilt

computer will use before you buy a motherboard. This

is because most motherboards are able to use only onetype of RAM.

When using dual-channel DDR, pairs of identical

RAM modules work in tandem to greatly improve performance. Both the size and

the speed (and preferably, the manufacturer, in my experience) of each RAM

module in a dual-channel pair must be identical.

If you're building a machine around the Intel Core i7 processor, then you'll

certainly want to use DDR3 RAM, which is capable of data transfer rates twice

those of DDR2.

How Much RAM do I Need?

Windows 98/Me: 256 to 512 MB

Windows 2000/XP: 1 GB to 4 GB

Windows Vista / Windows 7 32-bit: 2GB to 4 GB

Windows Vista / Windows 7 64-bit: 6 GB to 16 GB

Ubuntu (or other Linux with X-Server) 32-bit: 1 GB to 4 GB

Ubuntu (or other Linux with X-Server) 64-bit: 4 GB to 16 GB


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Finally, if you're using a 32-bit operating system, then don't bother installing any

more than 4 GB of RAM. A 32-bit system can only address about 3.5 GB, so

buying anything above that is just wasted money.

RAM Speed

The speed of RAM you will need depends mainly on the motherboard. You

generally should choose the highest speed of RAM that the motherboard supports.

Make sure that you check the motherboard documentation to find this out. Just

because a stick of RAM fits in a motherboard doesn't mean it will work.

Sometimes, inserting the wrong RAM and powering up the mobo can damage the

board, the RAM, or both.

Proper Insertion of the RAM Modules

RAM modules are keyed with little notches that fit

over corresponding tabs in the RAM slots. We've

circled them in the picture on the right (click the

picture for a close-up).

Before inserting the RAM module, make sure that the

notches and tabs are correctly lined up. If there are more notches than there are

tabs (or vice-versa), then you have the wrong RAM for your motherboard. Same

thing goes for if the notches and tabs don't match up. You have the wrong RAM,and all the force in the world won't make it the right RAM.

Once you're sure you have the right RAM, to actually insert it, simply push it

firmly, straight down into the slot, and push the retainer clips inward. That's it.

Integrated Video

Some motherboards come with integrated (built-in) audio and/or video cards.Depending on the quality and price range of the board, on-board video processors

can range from absolutely horrible to quite good.

For word processing and checking email (or for use on a file server), almost any

decent integrated video chip probably will do. But for most other users who are

considering a board with integrated video, it should be evaluated according to the


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same factors you would use when deciding upon an add-on video card. You also

should inquire as to whether the on-board video processor has its own dedicated

RAM or shares a portion of the system RAM. (Dedicated video RAM is definitelya plus in terms of performance and stability.)

Finally, even if the motherboard you are considering has integrated video, make

sure it also has expansion slots in case the on-board video fails, or in case you later

decide to disable the on-board video and upgrade to an aftermarket video card.

Factors Affecting Video Card Performance

To a newbie shopping for a video card, the long list of specifications and features

on the card's packaging may seem like a foreign language. But hidden somewhere

in all that geekspeak are important facts that can help you estimate how well the

card will work for you.

The most important factors affecting video card performance include:

Type of Interface

• PCI-Express. The PCI-E bus is the current standard, replacing the AGP bus

as the interface of choice for high-end video cards due to its phenomenal

data speed.• AGP (Accelerated Graphics Port). AGP is a dedicated, high-bandwidth

interface that is custom-tailored to video cards. AGP speeds of up to 8X are

still available. The card's speed should match the speed of the motherboard's

AGP interface.

• PCI. PCI video cards are still available, but are used mainly as replacements

or upgrades for pre-AGP motherboards.

Amount and Type of Video RAM

All video cards have at least some RAM on the card. The amount and speed of the

onboard RAM has a major effect on the card's performance.

For typing documents in Word, any old video card with any old RAM will suffice.

But for image manipulation, video editing, watching DVD movies, gaming,


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watching HDTV, or running CAD/CAM applications, more and faster RAM is

needed. For these uses, you should consider an AGP or PCI-E card with at

least 512 MB of fast RAM (like DDR-SDRAM). For high-end gaming or videoediting, 1024 MB would be even better

3-D/Open GL Support

All but the very lowest-end video cards come with 3D and Open GL support. Open

GL is the industry standard for high-performance video, and is supported on

Windows, Mac, and Unix machines, as well as on many industrial and other

specialized devices.

Cooling

Most high-end and many mid-range video cards now come with their own onboard

cooling fans. This little feature can make a big difference when using the computer

for video, gaming, or other graphics-intensive applications.

Aftermarket coolers are also available quite inexpensively for many video cards

that don't come with them. (They're usually the same fans that are used as

motherboard chipset coolers.) But installation of a fan on a video card can be alittle tricky, so be careful.

Video Card Inputs and Outputs

One simple but important feature to be considered in selecting a video card is the

type of inputs and outputs it has. The types of inputs and outputs will determine

what type of monitor and other video peripherals (video cameras, editing consoles,

etc.) you can attach to your homebuilt computer.

So think ahead to what you may want to use your computer for a year or so downthe road. Maybe you'll want to make videos of your family, for example.


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Outputs

In the recent past, almost all computers used standard SVGA analog monitors that

connected via a standardized connector; and in the past, all video cards had an

SVGA output.

Nowadays, the VGA-style monitor connector is slowly being replaced by the DVIconnector. In addition, an increasing number of video cards come equipped with

special connectors for specialized purposes. It's vital to choose a card that has the

correct connectors for whatever it is you want to attach it to.

For most users, all this means is that the video card has to match the monitor. But

some users will also want outputs for DV, NTSC, S-Video, RF, HDTV, or other

specialized connections.

There also are "dual-head" video cards that can feed two monitors.

Inputs

Some high-end video cards also are designed to allow input from video sources.

These cards are used for video production, editing, capture, and many other

purposes that involve transferring images from external devices onto a computer.

Some of the more popular input connectors found on video cards include:

• NTSC, PAL, and SECAM. These are "old" television video standards used

in various parts of the world (the United States uses NTSC). Theseconnections combine the red, green, and blue video channels, sync pulses,

and so forth into a "composite" video signal. All three of these standards are

expected to fade into history as HDTV (High-Definition Television)

becomes the norm.


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• RGB handles the video signal as separate red, green, and blue components.

RGB is used primary for video processing equipment, television projectors,

and professional-quality video monitors and recorders.

• S-Video offers higher definition than the NTSC, PAL, or SECAM

composite standards, but less definition than HDTV. Many high-end video

cards offer S-Video inputs and outputs.

• YPrPb is the HDTV equivalent of an S-Video connector. It allows direct

connection of a video card to High-Definition televisions and other HDTV

devices

• RF (Radio Frequency) inputs are used on cards (such as the ATI All-in-

Wonder series) that accept input from standard broadcast or cable television

signals. These cards have built-in TV tuners that allow the computer to be

used as a television or to be connected to VCR's, certain security cameras,

and other devices that use a modulated RF output.

• HDTC inputs allow High-Definition television signals to be viewed on thecomputer, subject to the limitations of the monitor.

Hardware DVD Players

Many high-end video cards include hardware DVD players. Hardware DVD

players decode and process most of the DVD data on the video card itself. By

contrast, software DVD-viewing programs use the computer's resources to process

the DVD data and present it to the user as audio and video. Hardware DVD players

usually produce better playback quality while utilizing far fewer system resources.

(Of course, to play DVD's on your computer, you will also need a DVD-ROMdrive.)

Vidcap Features

Vidcap (short for "video capture") means making a still image from a video and

saving it, usually as a JPEG file. It can also refer to a card that is able to capture a

video from an external source (like a DVD player or camcorder) and save it as afile on the computer for later viewing or editing.


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Audio Capabilities

Some video cards include their own audio inputs and outputs, as well as audio

processors that allow sound signals to be decoded from (or encoded into) mixed-media audio/video files or television signals.

Specialized Video Systems

Finally, a few video cards are specially designed to work as part of a dedicated

audio/video editing system.

These systems used to cost tens of thousands of dollars and were used solely by

professionals in the broadcasting or motion picture industries. Nowadays, however,very sophisticated systems capable of producing broadcast-quality video are

available to amateur video enthusiasts for less than a thousand dollars (notincluding the cost of the computer itself).

Integrated Audio

Many motherboards come with integrated (built-in) audio cards. Depending on the

quality and price range of the motherboard itself, on-board audio processors can

range from truly horrible to quite excellent.

If you are considering a motherboard with integrated audio, we suggest you also

make sure that it has expansion slots in case the on-board audio fails, or in case

you later decide to disable the on-board audio and upgrade to an aftermarket soundcard.

Finally, as we have stated before, bear in mind that most on-board audio cards are

designed with Windows in mind. If you plan on installing a different operating

system, make sure that the onboard sound will work with that OS before you spend

any money on the board.

Network Cards and Modems

Network Cards

A network card (also known as a Network Interface Card, NIC, Network Adapter,

or Ethernet card) is used to connect a computer to a high-speed network. If your


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homebuilt computer will be on a local network (or if you ever plan to use cable,

FIOS, satellite, or DSL Internet service) then you should install a NIC if one isn't

built into the mobo.

High-quality networks cards are inexpensive enough that it really doesn't pay to

skimp. The five bucks or so that you may save by using an el-cheapo NIC isn't

worth having to drive (or ride your bike) to the computer store, buy a new one, re-

open your computer case, and install new drivers when the cheap NIC fails.

Most NIC's today still use the 10/100 Mbps Fast Ethernet protocol, but the 1000

Mbps Gigabit Ethernet standard is catching on. Right now, Gigabit Ethernet cards

are still a bit more expensive (no pun intended) than 10/100 Mbps cards; but as

their prices continue to fall, Gigabit Ethernet will become the new standard. Most

new mobos have them built in.

Modems

The word "modem" is short for "modulator/demodulator." A modem converts your

computer's digital data to analog data that can be sent over a POTS (plain-old

telephone service) line, and converts incoming analog data to digital data that thecomputer can work with.

Better-quality modems have built in controllers that do the work right on the card.

They produce a faster, more stable, and more reliable connection than do cheap

software modems. External modems that connect to a computer's serial or USBport are also available.

Integrated NIC's and Modems

Many motherboards have integrated (built-in) network cards and/or modems

(although modems are becoming less common as fewer people are using dialup

Internet service). The quality of these built-in adaptors range from truly horrible to

quite good, depending on the quality and price range of the board.

If you select a motherboard with a built-in modem or NIC, make sure that there areexpansion slots available for an aftermarket card, just in case the on-board device

ever fails or doesn't work to your satisfaction. And yes, once again, remember that

on-board devices are designed with Windows in mind, and they may not work with

other operating systems.


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Proper Insertion of Expansion Cards

Like RAM, expansion cards and slots are keyed. Theyhave little notches with corresponding tabs in the slot

that are designed to prevent you from installing the

wrong card.

So if the card doesn't seem to fit, check those notches

and tabs. Don't break out a hammer and try to pound it in. You probably are trying

to insert the wrong kind of card (or insert the card in the wrong kind of slot).

Notice in the picture on the right that the AGP video slot is set back from the restof the slots and is of a different size. In addition, the various ridges, tabs, and so

forth on the card and the slot are intended to help prevent incorrect insertion or

incompatible cards. You should read the documentation for your motherboard andcards to make sure they are compatible.

The card shown in this picture is a network card that fits into the PCI slot. Notice

that it is keyed to the slot. (Also note that the card is only slanted to make it easier

for you to see the slot. Expansion cards, like RAM, are pushed straight down intotheir slots, like in the next picture down.)

You may have to use some oomph here. If the card doesn't seat itself using

fingertip pressure, place your palm over the card and push down firmly and evenly

until you feel the card pop into place. But first check the slots, notches, and tabs to

make sure you're not trying to install the card in the wrong slot.


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Finally, secure the card into place by screwing the card's metal bracket into the

screw hole over the expansion slot opening on the back of the case. Some cases

don't use screws, and instead have some sort of metal or plastic clip that holds the

card (or all of them, sometimes) in the motherboard. Usually this is obvious, but

check the manual that came with the case if you're confused.

Installing Auxiliary Drives in your Computer

There are several different types of auxiliary drives available for your homebuiltcomputer, such as CD-RW and DVD-RW drives, ZIP drives, tape drives, and

drive-like devices such as card readers. The installation procedures for all of these

devices are quite similar.

For this demonstration, we will be installing a CD-RW drive on an EIDE interface.

Other types of interfaces also are available (SATA and SCSI). The process is

exactly the same for installing a device like a card reader, except that there may be

an additional connection to the USB header on the motherboard, or to an add-on

card.

Like any other EIDE device, the first step in installing a CD-RW drive is to decide

where it will be positioned in your particular drive configuration (that is, as a

master or a slave), and to set the jumpers accordingly.

Choosing a Hard Drive


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What, Exactly, is a Hard Drive?

A hard drive is a stack of magnetic disks that spin at

very high rates of speed (7200 RPM for a modern

EIDE or SATA drive, and 10,000 RPM for a SCSI

drive) and are used to store your computer's data.

Unlike RAM, the hard drive is a semi-permanent

storage device. It is non-volatile. That means it

continues to hold data even when power to the drive is turned off (or even if the

drive were removed from the computer, for that matter). A properly functioning

hard drive will retain data until the user or a program instructs it to delete ormodify that data.

Types of Hard Drives

There are several different types of hard drives available for desktop computers,

distinguished mainly by the interface, or type of connection, between the drive and

the computer.

• Very high-end computers often use SCSI (pronounced "skuzzy" and

standing for "Small Computer Simplified Interface") drives, which are

capable of higher data transfer rates. But for most home computer users,

SCSI drives are prohibitively expensive. They also require special

controllers and are a bit complicated for most beginners to configure.• Until recently, most home and small office computers used EIDE (Enhanced

Integrated Drive Electronics) drives, which were commonly known

as ATA (short for ATAPI) drives. Nowadays they're called PATA (Parallel

ATA) drives, to distinguish them from SATA (Serial ATA) drives. The

designation ATA is followed by a number (33, 66, 100, or 133) that gives

the drive's maximum data transfer rate in MB/second. ATA-33 and ATA-66

hard drives are now obsolete. ATA-100 and ATA-133 are still available, but

are rapidly being replaced by SATA drives.

•

Almost all new desktop and laptop computers use Serial ATA(SATA) drives. SATA replaced the EIDE hardware interface while

maintaining the ATA command set, enabling much faster data transfer rates

than EIDE drives, but with fewer compatibility and configuration issues than

SCSI drives. SATA drives also are less expensive than SCSI drives of comparable capacity.


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Master Drives and Slave Drives

One of the more confusing aspects of EIDE hard drive configuration for those new

to computer building is the master/slave relationship. It's actually not very hard tounderstand, however.

Traditionally, most motherboards had two EIDE interfaces (primary and

secondary). Each interface could support two devices, making a total of up to four

drives. Newer motherboards may have only one EIDE interface, or none at all, as

SATA has become the new drive standard. If you plan to use EIDE (PATA) drives,

make sure you buy a motherboard that supports PATA. (You also can buy an add-

in PATA controller.)

The primary EIDE connection will be labeled on the

motherboard as either IDE-0 or IDE-1, depending on

the mood of the person who made up the stencil. If

they chose to use IDE-0 and IDE-1 for the two

channels, then the primary is IDE-0. But if they are

labeled IDE-1 and IDE-2, then IDE-1 is the primary.

(They may also be labeled as EIDE or ATAPI, rather

than IDE, on some boards. It all means the same

thing.)

Because modern IDE controllers are integrated into the drives, not mounted on the

motherboard, the drives have to decide for themselves how to share the same IDEinterface.

To accomplish this, one drive on each interface is assigned as the "master," and the

other drive (if present) is assigned as the "slave." The controller on the master

drive also controls data transfer in and out of the slave drive. When the master

drive is idle, the slave drive may transfer data. But if the master drive iscommunicating with the computer, then it instructs the slave drive to wait.

By convention, the master drive is attached to the connector

on the IDE cable that is farthest from the motherboard (that

is, the one at the very end of the cable) and closest to the off-

center middle connector. On an 80-conductor cable, the

connectors are also color-coded: The master gets connected

to the black connector, the slave to the gray, and the blue to the motherboard.


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Using Cable Select

Many drives also offer a "cable select" (CS) option. When using cable select, each

drive is jumpered to the "CS" setting. A special signal is sent to pin 28 of the drive

attached to the master drive connector, which instructs that drive to become the

master drive and to assume the duties of controlling data transfer on that EIDE

channel. Conversely, because this signal is absent on the drive connected to the

slave connector, that drive assumes the slave mode. Pretty smart, huh?

We suggest you use the CS setting on all PATA drives. Why? Because it saves you

the aggravation of having to remove existing drives to look at the little label and

see how to reset the jumpers if you change the drive assignment or add a drive lateron.

IDE and Floppy Drive Cables

IDE Ribbon Cables

IDE/EIDE cables are used to connect older-style PATA hard

drives and other PATA devices to the computer's

motherboard.

Traditionally, IDE cables were flat, gray, ribbon-type connectors. Older (ATA-33)

IDE cables had 40 conductors and forty pins. Newer ATA-133 EIDE cables have

80 conductors, but still have forty pins. The colored stripe along one edge of the

cable aligns with pin number one on the device and motherboard connectors.

80-conductor EIDE cables have color-coded connectors:

• The blue connector gets attached to the motherboard.

• The black connector attaches to the master drive or device.

• The gray connector attaches to the slave drive or device.

The drive positions on older, 40-conductor IDE cables can be determined by their

relative positions along the cable:

• The off-center middle connector gets attached to the slave device.


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• The connector closest to the middle connector gets attached to the master

device.

• The connector farthest from the middle connector gets attached to themotherboard.

Floppy Cables

Floppy drive cables look a lot like IDE cables except that

they are a little narrower, have only 34 conductors, and have

a twist at the end of the cable that attaches to the drives. They

may have from two to five connectors: one to attach to the motherboard, and as

many as four drive connectors.

Why as many as four? Well, prior to the advent of hard drives, most PC's had twofloppy drives (A: and B:), both of which were connected to a single controller by

the same cable. When the ancient 5.25-inch floppy drives were replaced by 3.5-

inch drives (which have different connectors), cable manufacturers began

including both types of connectors on floppy drive cables. So the same cable could

have one connector for the motherboard, two connectors for 5.25-inch drives, and

two connectors for 3.5-inch drives. But the total number of floppy drives is stilllimited to two; the "wrong" connectors simply go unused.

Since few computers today have two floppy drives (most don't even

have one anymore), and most of us haven't seen a 5.25-inch drive in years, mostfloppy cables manufactured in this century have only two connectors: one end gets

attached to a 3.5-inch floppy drive, and the other end gets attached to themotherboard.

Round EIDE and Floppy Cables

Nowadays, ribbon cables are being replaced by newer, round

cables. They are available in all sorts of colors to suit anytaste or decor. But the real advantage to round cables is that

they don't block airflow inside the case as much as flat cables

do.


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As computers become more and more powerful, they generate more and more heat;

and the added airflow that round cables allow can make a big difference in a

computer's stability and performance.

SATA and SCSI Cables

SATA Cables

SATA (Serial ATA) cables are used to connect high-

speed SATA hard drives and optical drivesto the

motherboard. SATA cables have only seven conductors and

are therefore much thinner than ribbon-type IDE cables,

which improves airflow and makes them easier to route

inside the case. There are also eSATA cables that can be used to connect externalSATA drives to a computer.

SATA cables can be as long as one meter in length and are more rugged than IDE

cables, which provides for more flexibility in choosing where to mount hard

drives. They're also capable of very high data transfer rates -- as high as 300

MB/sec.

PATA Drive Jumper Settings

Note: Much of the information provided on this page is obsolete as SATA has

replaced PATA as the standard drive on new computers. SATA drives have no

master / slave relationship, and therefore don't need to be jumpered.

So if you are building an all-SATA system, then none of the information on this

page applies to you, and you can skip this page if you like. If you're building a


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system that uses SATA hard drives and PATA auxiliary drives, then the information

on this page applies only to the PATA auxiliary drives, not to the SATA hard

drives.

Setting the Drive Jumpers

Once you decide on the drive positions and assignments in your new computer, the

jumpers must be set accordingly.

At this point, let's mention again that all devices attached to the IDE channels --

hard drives, optical drives, tape drives, ZIP drives, and whatever other IDE/ATA

devices may someday exist -- must be configured either as masters, slaves, or

cable-select devices. If there is only one device on the channel, then it is themaster. (Note: Some drives have a separate jumper setting for "single" drive.)

You can't have two masters or two slaves on the same IDE channel. This is one of

the most common mistakes made by new home computer builders, so double check

your assignments and jumpers before firing the machine up for the first time.

The diagram below shows the jumper assignments for one popular line of EIDE

hard drives. Your drive's jumper settings may be different and can be found in

the drive's documentation and/or on a label attached to the drive. (Diagram

courtesy of Maxtor Corporation.)


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The blue boxes represent the little jumpers that came

in that little plastic bag that came with the drive. The

jumpers usually are white, black, or blue in color. The

pin settings are printed on the drive's label, on its logic

board (as in the picture on the right), or both.

To bridge a connection, you slide a jumper over the

corresponding pins as in the picture on the right.

Plastic tweezers come in handy for this. If you use metal tweezers, be careful not to

touch the metal pins. (Or better yet, just use your fingernails.)

If you dropped the jumpers in the carpet, good luck finding them!

The Cylinder Limitation Jumper

Some hard drives include a cylinder limitation jumper (CLJ) to work around the

limitations of older BIOS's that are not able to support larger drives. Unless you are

using a motherboard that was built the year of the flood, this is not likely to be anissue for you; so most likely you will leave the CLJ off.

(Once again, if you are using all SATA drives, then none of this stuff applies to

you.)

Auxiliary Storage Devices

In addition to your hard drive(s), you will undoubtedly want to install other drives

on your homebuilt computer. We're calling these "auxiliary drives" to distinguish

them from the hard drive. Auxiliary drives include:

Optical Drives

Optical drives include CD-ROM drives, CD-RW drives

("burners"), DVD-ROM drives, and DVD+/-RW drives.

They use lasers to read and/or write data. Some optical


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Once you have decided on the drive configuration and have put the jumpers where

they belong, you can begin to physically install the drives. When deciding where to

place the drives, keep both convenience of use and cable routing in mind.

In most cases, You'll have to remove both a plastic cover and a metal plate from

the drive bay where you will be installing the drive. Most often, you do this by

removing the plastic cover, and then prying the metal plate from the rest of thecase using a screwdriver.

Also be careful that the drive, once inserted, doesn't come too close to fans or push

up against motherboard components. Some drives are slightly longer than average,

and if you push them in fully without looking first, you may damage something on

the motherboard.

Finally, secure the drive into place with the mounting screws, and connect the data

and power cables.


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Some optical drives also have a legacy audio connector that connects to the sound

card. It's obsolete technology and chances are that you don't need it. But it does no

harm to connect it if your sound card or motherboard has a connector for it.

Installing the Cabinet Fan

While we're at it, let's also install the cabinet fan. On our case, the

cabinet fan is mounted in a fan shroud, which is in turn snapped

into the computer case. Other cases simply have holes for the fan

to be directly mounted to the case using special screws that come

with the fan.

Some people always mount the cabinet fans to blow the air outward, to avoid

sucking dust into the computer. Others say you should install the front panel fan to

draw the air inward, and the rear panel fan to blow the air outward. We say it

depends. If the computer is going to be used in a dusty place, point the fan to blow

the air out to avoid dust. If not, then point it in to increase airflow.

Either way, a cabinet fan or two will go a long way towards keeping yourcomputer cool and comfy.

Installing the Front Panel Connectors

We're almost finished!

One somewhat tedious but vital step in assembling your

homebuilt computer is to connect all those little wires for the


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front-panel switches and LED's from the case to the motherboard.

If you purchased a "barebones" computer with the motherboard already mounted,

then this was probably done for you already. Otherwise, you'll have to do it

yourself. Hopefully, you have good eyes and can read the tiny lettering on both theconnectors and the motherboard. Otherwise, break out the bifocals!

Each switch and LED on the front panel has a

connector attached to it that must be connected to theappropriate pins on the motherboard.

Some of the connectors (especially the LED's) are

polarized, meaning that they have to be connected in

the correct polarity. Polarized connectors have a little

arrow or a plus sign by the positive wire, but no

keyway to prevent you from attaching them backwards.

The basic front panel headers found on most motherboards are those for the PC

speaker (the one built into most cases that beeps when the computer passes POST),

the power switch, the reset switch, the hard drive activity LED, the power LED,

and sometimes a few others. Of these, the leads for the LEDs must be connected inthe proper polarity in order to work properly. The rest should be connected in the

proper polarity just for the sake of doing things professionally, but they will work

even if they're attached backwards.

Time to Double-Check

Before firing up your new computer, take a few moments to double check the

following items:

• Check all the fans to make sure they are

properly connected. Starting up your computer

with the CPU fan disconnected will likely kill

your processor!


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Floppy Drive Power Connectors

Floppy drives and some older CD-ROM drives and other IDE

devices connect using an even smaller power connector called

a P7, which is shown on the right. Although the connector is

keyed, it's very easy to force it on the wrong way. Even a

skinny-armed geek can do it. So if it doesn't slip on easily, you probably have it on

backwards. Don't force it! Think brains, not brawn.

As with hard drives, if you connect a floppy drive's power cable backwards for so

much as a moment, you will destroy the drive. So be sure that you don't have the

power connector reversed.

ATA Power Connectors

And as if the existing assortment of power connectors weren't enough,

SATA drives use yet another type of power connector that's specially

designed to enable "hot-swapping" the drives.

If your power supply doesn't have SATA connectors (pretty much all new ones

will), you can purchase inexpensive adapters that will convert a Molex connector

to a SATA connector (or voce-versa, depending on which kind of power connector

you're short of).

P1 Connector

The main power to the motherboard is provided by something

called the P1 connector, appropriately enough. The P1

connector is keyed to help prevent incorrect insertion and is

held tight on the motherboard by a little plastic clip. If it

doesn't fit, don't force it. You're probably trying to attach it backwards.


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Never plug an ATX power supply into AC power unless the P1 connector is

connected either to a motherboard or to a test load. Plugging an ATX power supply

into AC power while the P1 connector is not connected to a load will destroy thepower supply.

P4 Connector

Intel Pentium 4 and some AMD Athlon computers also

require a special connector known, appropriately enough, as

the P4 connector. This is located on the motherboard, usually

(but always) somewhere near the CPU. On computers that don't need the P4

connector, it is unused. Just tie it off out of the way of fans, other components, andmetal parts.

Some other components, such as certain high-end video cards, also have a P4

connection.

Fan Power Leads

Most motherboards have a connector for the leads for the CPU

fan and at least one case fan. These provide both power and, in most cases, RPM

monitoring and thermal control. If your motherboard has a header labeled CPU

FAN, that's what it's for. Some motherboards also have headers for the chassis fan

and/or the chipset cooler, as well.

Front Panel Leads

Every computer case comes with a set of wires that connects

the motherboard to the LED's and switches on the front panel.

These connectors include those for the power and reset

switches, the power LED and hard drive activity LED, and the


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system speaker. They connect to a bus block on the motherboard.

Unfortunately, there's no standardization regarding the exact location of the panelheaders. You'll just have to read the mobo manual to find the correct positions.

Firing Up Your Homebuilt Computer

Before starting your computer for the first time, take a moment to check

the computer parts yet again, making sure everything is properly connected and

seated inside the box. Make sure the wires aren't blocking the fans. Makes sure

there are no screws rattling around, and that you didn't leave any tools inside the

machine.

Otherwise, take a look on the back of the computer at

the power supply. Chances are that you will see a little

slider switch. Make sure that this switch is set to the

correct voltage for your part of the world.

In the United States, the correct power setting will be

110 - 120 volts. In your part of the world, well, I have

no idea. Ask someone local if you are unsure.

Plug the power cord into the power supply, and the other end into a surge-protectedAC power source or a battery backup. Hook up the keyboard, monitor, and mouse

to their appropriate connectors, and press the power button.

And pray.

The CMOS Setup Screen

If you have done everything correctly, after a few

seconds you will hear a delightful beep as thecomputer passes its very first POST (Power-On-Self-

Test), and you may be greeted by a screen that looks

something like the one on the right. (You may have to

press DELETE, F2, or some other key to get to this

screen, depending on your motherboard. Read the manual.)


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What you are seeing is something called the CMOS setup screen (or the BIOS

setup screen). This is all your computer is capable of doing until you install an

operating system on it, and the settings you select will affect the way your OS

performs. Most computers come with CMOS settings designed for Windows, so

you may not need to do anything at all.

But here are a few basic suggestions:

1. Start with the default settings. You can tweak them later if you like. Just

check to make sure that the time and date are correct. You can use local time

or Coordinated Universal Time (Greenwich time). Most Windows machines

use local time, and most Unix and Linux machines use Greenwich time; but

either will work either way.

2. If you don't know what something means, leave it alone. Use the default

settings unless you know what you are doing.3. Make sure that all of your drives are showing up. If not, then shut down the

machine, unplug it, and check all your drive connections and jumper settings

again.

4. Before installing your operating system, make sure that the CD-ROM drive

is set as a bootable device (unless you will be booting from a floppy for the

installation, in which case make sure the floppy drive is set as a bootable

device). You can usually find the settings for the boot sequence in a section

of the CMOS screen called, appropriately enough, Boot Sequence.

5. Make sure the date and time are correct before installing the OS. Incorrect

dates and times can cause all sorts of problems.

Once you've finished CMOS setup, saved the settings, and rebooted, you're ready

to install the operating system.

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