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Identifying Personal Computer Components

Chapter 2

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Overview

• In this chapter, you will learn to

– Describe how the PC works– Identify the essential tools of the trade and avoid

electrostatic discharge (ESD)– Identify the major internal and external

components of a PC– Identify the different connectors on a typical PC

system unit

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How the PC Works

• Software– Operating system (Windows, MAC OS X, Linux)– Applications (PowerPoint, Word, Outlook, Internet

Explorer)

• Hardware– Pieces you can touch (mouse, monitor,

motherboard, etc.)

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How the PC Works

• Computer functions through four stages:– Input provides the computer with data

• Keyboard and mouse

– Processing occurs when the computer processes or manipulates your data

– Output is provided as the result of processing your data

• Monitor, printer, speakers

– Storage is how you keep your data for later use• Hard drive, CD-ROM disc, floppy diskette

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Tools of the Tradeand ESD Avoidance

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PC Tool Kit

• The basic tech toolkit: a Phillips-head screwdriver – Most toolkits contain a few other items

• It’s a good idea to include– Magnifying glass– Small flashlight

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IT Essentials

CompTIA A+Essentials

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Electrostatic Discharge

• Electrostatic discharge (ESD) is the passage of a static electrical charge into your PC or a PC component such as a RAM stick

– Static electricity can destroy sensitive parts of a PC

– ESD damage is much more prevalent in dry, cool environments

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Anti-static Tools

• Anti-static wrist strap– Keeps you and the PC at

the same electrical potential to prevent ESD

• Anti-static mats– Used temporarily to place

parts taken out of your PC

• Anti-static bags– Used to store electrical

components from your PC

• Always unplug a PC when you work on it. Don’t just turn it off.

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The Complete PC

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External Connections

• Plug goes into a port• Port/jack accepts a plug• Connector can be either a port or a plug

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DIN Connectors

• DIN connectors are round and come in two sizes:– DIN– Mini-DIN

• Always a female connector

• Used frequently by a keyboard or mouse

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USB Connectors

• Universal Serial Bus (USB)– Used by many devices

today– Devices are hot-

swappable• You can insert or remove

the device while the PC is powered on

– USB B plugs into devices

– USB A plugs into computers

USB B

USB A

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FireWire Connectors

• FireWire connectors move data at incredibly high speeds– Also known as IEEE 1394– Popular with video applications– Uses 6-wire connector (note the rounded edge)– Hot-swappable

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DB Connectors

• DB connectors have a slight D-shape– Male DB connectors have pins– Female DB connectors have sockets– Oldest type of connector in the PC

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RJ Connectors

• Registered jack or RJ connectors

• RJ-11 used by telephone lines

• RJ-45 used in network interface cards (NICs)

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Audio Connectors

• Audio connectors are used on sound cards

– Used to connect speakers, microphones, and other audio devices

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Devices and Their Connectors

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Cards vs. Onboard

• Connectors exposed on rear and front of PCs

– Some connectors attach directly to motherboard

– Some connectors attach to boards that plug into motherboard

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Keyboard

• Keyboards connect into dedicated mini-DIN (usually purple) or USB

• Plugs and ports usually purple

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Video Cards

• Video cards connect to monitors– S-Video connector (left)– Digital video interface (DVI) connector (center) – 15-pin female DB connector (right)

– Newer High-Definition Multimedia Interface (HDMI)

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Sound Cards

• Sound cards – Convert digital information into sound– Convert sound from a microphone into digital data– Mini-audio jacks for speakers and microphones– DB-15 connector for a joystick or musical instrument– Newer Sony/Phillips Digital Interface Format (S/PDIF)

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Network Cards

• Networks: groups of PCs connected together

– Network interface cards (NICs) typically on motherboard (can be expansion card)

– Typical connector is RJ-45

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Mouse

• A mouse enables you to select graphical items on a screen

– Connects through mini-DIN port (usually light green) or USB port (most common)

– Trackball may be used instead of mouse

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Modem

• Modems convert analog telephone signals into digital data and vice versa

– Internal modems are expansion cards

– External modems connect to a serial port

– Uses two RJ-11 sockets• One to the telephone jack in the wall• One to a telephone if you wish

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Serial Ports

• Serial ports are used to add external devices to a PC

– Accept and transmit serial data

– Male DB-9 or DB-25

– Largely replaced by USB

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Printer

• Printers output data from the PC onto paper

– Historically used a female DB-25

– Today printers almost exclusively use a USB or FireWire port

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Joystick

• Joysticks are used almost exclusively to play games on the computer

– Originally designed as an input device to be used like a mouse

– Connector typically orange

– Most joysticks now use USB

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Inside the System Unit

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Case

• The case houses all of the internal components– Protects internal components– External connections in front and rear– Provides access to storage devices such as CDs

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CPU

• Central processing unit (CPU)

– Also called a microprocessor

– Performs calculations

– CPUs generate a lot of heat

• Cooling fan and/or heat sink used to keep them cool

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CPU

• Makes– Intel– AMD

• Models– Celeron– Athlon– Sempron– Pentium

• CPUs come in different packages– Pin grid array (PGA)

• Most common today

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RAM

• Random access memory (RAM)– Stores programs and data currently used by the

CPU

– Measured in megabytes (MB) and gigabytes (GB)

– Each piece or module of RAM is called a stick• Dual inline memory module (DIMM) most common today

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Motherboard

• The motherboard is a thin, flat piece of circuit board

– Everything connects directly or indirectly to the motherboard

– Contains sockets for the CPU, RAM, power, and external devices such as mice, printers, and keyboards

– Expansion slots allow the addition of new components

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Power Supply

• Provides electrical power to PC components– Uses 110VAC power from the

wall outlet

– Has power connectors for the motherboard and other devices

– Uses a fan to keep itself and the PC cool inside

– Safety Alert• High voltage capacitor holds power

after unplugged

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Floppy Drive

• The floppy drive uses floppy diskettes to store data– Connects to the computer via a ribbon cable

– Connects to the floppy controller on the motherboard

– Uses a connector from the power supply

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Hard Drive

• Hard drives store programs and data not currently in use by the CPU– Capacity quoted in megabytes (MB) or gigabytes (GB)– A typical PC has one hard drive but may contain more– Common types include

• Parallel AT attachment (PATA)• Serial AT attachment (SATA)• Small computer system

interface (SCSI)

• Uses a power cable from the power supply

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Optical Media

• Two groups

– CD• Stores about 700 MB• CD-ROM (read only)• CD-R, CD-RW (allows

writing to CD)

– DVD• Stores about 4 GB of data• DVD-ROM, DVD+R, DVD-

R, DVD+RW, DVD-RW