>computers

Identify the names, purposes and characteristics of
storage devices

FDD

HDD

CD/DVD/RW (e.g. drive speeds, media types)

Removable storage (e.g. tape drive, solid state such
as thumb drives, flash and SD cards, USB, external
CD-RW and hard drive)

Identify the names, purposes and characteristics of
motherboards

Form Factor (e.g. ATX/BTX, micro ATX/NLX)

Components

Integrated I/Os (e.g. sound, video, USB, serial,
IEEE 1394 / firewire, parallel, NIC, modem)

Memory slots (e.g. RIMM, DIMM)

Processor sockets

External cache memory

Bus architecture

Bus slots (e.g. PCI, AGP, PCIe, AMR, CNR)

EIDE/PATA

SATA

SCSI Technology

4831x.book Page 1 Tuesday, September 12, 2006 11:59 AM
Chipsets

BIOS / CMOS / Firmware

Riser card / Daughter board

Identify the names, purposes and characteristics of
power supplies, for example: AC adapter, ATX,
proprietary, voltage

Identify the names, purposes and characteristics of
processor / CPUs

CPU chips (e.g. AMD, Intel)

CPU technologies

Hyperthreading

Dual core

Throttling

Micro code (MMX)

Overclocking

Cache

VRM

Speed (real vs. actual)

32 vs. 64 bit

Identify the names, purposes, and characteristics
of memory

Types of memory (e.g. DRAM, SRAM, SDRAM,
DDR / DDR2, RAMBUS)

Operational characteristics

Memory chips (8, 16, 32)

Parity versus non-parity

ECC vs. non-ECC

Single-sided vs. double-sided

Identify the names, purposes and characteristics of
display devices, for example: projectors, CRT and LCD

Connector types (e.g. VGA, DVI / HDMi, S-Video,
Component / RGB)

Settings (e.g. V-hold, refresh rate, resolution)

4831x.book Page 2 Tuesday, September 12, 2006 11:59 AM
Identify the names, purposes and characteristics of input
devices for example: mouse, keyboard, bar code reader,
multimedia (e.g. web and digital cameras, MIDI,
microphones), biometric devices, touch screen.

Identify the names, purposes, and characteristics of
adapter cards

Video including PCI / PCI-E and AGP

Multimedia

I/O (SCSI, serial, USB, parallel)

Communications including network and modem

Identify the names, purposes and characteristics of
ports and cables for example: USB 1.1 and 2.0, parallel,
serial, IEEE1394 / firewire, RJ45 and 11, PS2 / MINI-DIN,
centronics (e.g. mini, 36) multimedia (e.g. 1 / 8 connector,
MIDI COAX, SPDIF)

Identify the names, purposes and characteristics of
cooling systems for example heat sinks, CPU and case
fans, liquid cooling systems, thermal compound

4831x.book Page 3 Tuesday, September 12, 2006 11:59 AM
A

personal computer (PC)

is a computing device made up of
many distinct electronic components that all function together
in order to accomplish some useful task (such as adding up the
numbers in a spreadsheet or helping you write a letter). By this definition, note that were
describing a computer as having many distinct parts that work together. Most computers
today are modular. That is, they have components that can be removed and replaced with a
component of similar function in order to improve performance. Each component has a very
specific function. In this chapter, you will learn about the components that make up a typical
PC, what their function is, and how they work together inside the PC.

Unless specifically mentioned otherwise, throughout this book the terms

PC

and

computer

can be used interchangeably.

In this chapter, you will learn how to identify personal computer components, including
the following:

Motherboards

Processors

Memory

Storage devices

Power supplies

Display devices

Input devices

Adapter cards

Ports and cables

Cooling systems

Identifying Components of Motherboards

The spine of the computer is the

motherboard

, otherwise known as the

system board

(and less
commonly referred to as the

planar board

). This is the olive green or brown circuit board that lines
the bottom of the computer. It is the most important component in the computer because it con-
nects all the other components of a PC together. Figure 1.1 shows a typical PC system board, as
seen from above. All other components are attached on this sheet. On the system board, you will

4831x.book Page 4 Tuesday, September 12, 2006 11:59 AM
Identifying Components of Motherboards

5

find the central processing unit (CPU), underlying circuitry, expansion slots, video components,
random access memory (RAM) slots, and a variety of other chips.

Types of System Boards

There are two major types of system boards: integrated and nonintegrated:

Nonintegrated System Board

Each major assembly is installed in the computer as an expan-
sion card. The major assemblies were talking about are items like the video circuitry, disk con-
trollers, and accessories.

Nonintegrated system boards

can be easily identified because each
expansion slot is usually occupied by one of these components.
It is difficult to find nonintegrated motherboards these days. Many of what would normally be
called nonintegrated system boards now incorporate the most commonly used circuitry (such as
IDE and floppy controllers, serial controllers, and sound cards) onto the motherboard itself. In
the early 1990s, these components had to be installed externally to the motherboard.

F I G U R E 1 . 1

A typical system board

4831x.book Page 5 Tuesday, September 12, 2006 11:59 AM
6

Chapter 1

Identifying Personal Computer Components
Integrated System Board Most of the components that would otherwise be installed as
expansion cards are integrated into the motherboard circuitry. Integrated system boards
were designed for simplicity. Of course, theres a drawback to this simplicity: When one
component breaks, you cant just replace the component thats broken; the whole mother-
board must be replaced. Although these boards are cheaper to produce, they are more
expensive to repair.
With integrated system boards, there is a way around having to replace the whole motherboard
when a single component breaks. On some motherboards, you can disable the malfunctioning
onboard component (for example, the sound circuitry) and simply add an expansion card to
replace its functions.
System Board Form Factors
System boards are also classified by their form factor (design): ATX, micro ATX, BTX, or
NLX (and variants of these). Exercise care and vigilance when acquiring a motherboard and
case separately. Some cases are less flexible than others and might not accommodate the
motherboard you choose.
Advanced Technology Extended (ATX)
The ATX motherboard has the processor and memory slots at right angles to the expan-
sion cards. This arrangement puts the processor and memory in line with the fan output
of the power supply, allowing the processor to run cooler. And because those components
are not in line with the expansion cards, you can install full-length expansion cards in
an ATX motherboard machine. ATX (and its derivatives) are the primary motherboards
sold today.
Micro ATX
One form factor that is designed to work in standard ATX cases, as well as its own smaller cases,
is known as micro ATX (also referred to as �ATX). Micro ATX follows the same principle of
component placement for enhanced cooling over pre-ATX designs but with a smaller footprint.
With this smaller form come trade-offs. For the compact use of space, you must give up quantity:
quantity of memory modules, quantity of motherboard headers, quantity of expansion slots,
quantity of integrated components, even quantity of micro ATX chassis bays, although the same
small-scale motherboard can fit into much larger cases, if your original peripherals are still a
requirement.
Be aware, however, that micro ATX systems tend to be designed with power supplies of
lower wattage, in order to help keep down power consumption and heat production, which
is generally acceptable with the standard micro ATX suite of components. As more off-board
USB ports are added and larger cases are used with additional in-case peripherals, larger
power supplies might be required.
4831x.book Page 6 Tuesday, September 12, 2006 11:59 AM Identifying Components of Motherboards
7
New Low-profile Extended (NLX)
An alternative motherboard form factor, known as New Low-profile Extended (NLX), is used in
some low-profile case types. NLX continues the trend of the technology it succeeded, Low Profile
Extended (LPX), placing the expansion slots (ISA, PCI, and so on) sideways on a special riser card
to use the reduced vertical space optimally. Adapter cards, or daughter boards, that normally plug
into expansion slots vertically in ATX motherboards, for example, plug in parallel to the mother-
board, so their most demanding dimension does not affect case height.
LPX, a technology that lacked formal standardization and whose riser card interfaces
varied from vendor to vendor, enjoyed great success in the 1990s until the advent of the
Pentium II processor and the Accelerated Graphics Port (AGP). These two technologies placed
a spotlight on how inadequate LPX was at cooling and accommodating high pin counts. NLX,
an official standard from Intel, IBM, and DEC, was designed to fix the variability and other
shortcomings of LPX, but NLX never quite caught on the way LPX did. Newer technologies,
such as micro ATX, and proprietary solutions have been more successful and have taken even
more market share from NLX.
Balanced Technology Extended (BTX)
In 2003, Inte