meljun cortes computer organization lecture chapter2

8/13/2019 MELJUN CORTES Computer Organization Lecture Chapter2

1/41

Chapter 2

The Visible PC

MELJUN CORTES


2/41

2007 The McGraw-Hill Companies, Inc. All rights reserved

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


3/41

How the PC Works

`

Input

Output

Processing


4/41


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.)


5/41


How the PC Works Computer functions through four stages:

Inputprovides the computer with data Keyboard and mouse

Processingoccurs when the computer processes ormanipulates your data

Outputis provided as the result of processing yourdata Monitor, printer, speakers

Storageis how you keep your data for later use Hard drive, CD-ROM disc, floppy diskette


6/41


7/41

Tools of the Trade

and ESD Avoidance


8/41 2007 The McGraw-Hill Companies, Inc. All rights reserved

PC Tool Kit

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

Its a good idea to include

Magnifying glass

Small flashlight


9/41

IT Essentials

CompTIA A+Essentials



Electrostatic Discharge

Electrostatic discharge(ESD) is the passage of a staticelectrical charge into your PC or a PC component such

as a RAM stick

Static electricity can destroy sensitive parts ofa PC

ESD damage is much more prevalent in dry, cool

environments



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 partstaken out of your PC

Anti-static bags

Used to store electrical

components from your PC

Always unplug a PC whenyou work on it. Dont just

turn it off.


12/41

The Complete PC



External Connections

Plug goes into a port

Port/jack accepts a plug

Connector can be either a port or a plug



DIN Connectors

DINconnectors are round and comein two sizes:

DIN

Mini-DIN

Always a female connector

Used frequently by a keyboard or

mouse



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



FireWire Connectors

FireWire connectors move data at incredibly highspeeds

Also known as IEEE 1394

Popular with video applications

Uses 6-wire connector (note the rounded edge)

Hot-swappable



DB Connectors

DBconnectors have a slight D-shape Male DB connectors have pins

Female DB connectors have sockets

Oldest type of connector in the PC



RJ Connectors

Registered jackor RJconnectors

RJ-11 used by telephone

lines

RJ-45 used in network

interface cards (NICs)



Audio Connectors

Audioconnectors are usedon sound cards

Used to connect speakers,

microphones, and other

audio devices


20/41

Devices and Their Connectors



Cards vs. Onboard

Connectors exposed on rearand front of PCs

Some connectors attach

directly to motherboard

Some connectors attach to

boards that plug into

motherboard



Keyboard

Keyboardsconnect into dedicated mini-DIN(usually purple) or USB

Plugs and ports usually purple


23/41


Video Cards

Video cardsconnect to monitors S-Video connector (left)

Digital video interface (DVI) connector (center)

15-pin female DB connector (right)

Newer High-DefinitionMultimedia Interface (HDMI)


24/41


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)


25/41


Network Cards

Networks: groups of PCs connected together

Network interface cards (NICs) typically on motherboard (can

be expansion card)

Typical connector is RJ-45


26/41


Mouse

A mouseenables you toselect graphical items on a

screen

Connects through mini-DINport (usually light green) or

USB port (most common)

Trackball may be usedinstead of mouse


27/41


Modem

Modemsconvert analog telephone signals into digital dataand 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


28/41


Serial Ports

Serial portsare used to add external devices to a PC

Accept and transmit serial data

Male DB-9 or DB-25

Largely replaced by USB


29/41


Printer

Printersoutput data from the PC onto paper

Historically used a female DB-25

Today printers almost exclusively use a USB or FireWire port


30/41


Joystick

Joysticksare used almostexclusively 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


31/41

Inside the System Unit


32/41


Case

The casehouses all of the internal components Protects internal components

External connections in front and rear

Provides access to storage devices such as CDs

C


33/41


CPU

Central processing unit(CPU)

Also called a

microprocessor

Performs calculations

CPUs generate a lot ofheat

Cooling fan and/or heat

sink used to keep them

cool


34/41


CPU

Makes Intel

AMD

Models

Celeron

Athlon

Sempron

Pentium

CPUs come indifferent packages

Pin grid array (PGA)

Most common today

RAM


35/41


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

M th b d


36/41


Motherboard

The motherboardis 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 ofnew components

P S l


37/41


Power Supply

Provides electrical power to PC

components

Uses 110VAC power from the wall

outlet

Has power connectors for themotherboard and other devices

Uses a fan to keep itself and the PC

cool inside

Safety Alert

High voltage capacitor holds power after

unplugged

Fl D i


38/41


Floppy Drive

The floppy driveuses 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

H d D i


39/41


Hard Drive

Hard drivesstore 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

O ti l M di


40/41


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


41/41

meljun cortes computer organization lecture chapter2

Documents