edp 111c chapter 6

8/9/2019 EDP 111C Chapter 6

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McGraw-Hill/Irwin Copyright 2008 by The McGraw-Hill Companies, Inc. All rights reserved.

Chapter 6

The System Unit


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Competencies (1 of 2)

Describe the four basic types ofsystem units

Discuss how a computer uses binary codesto represent data in electronic form

Describe each of the major system unitcomponents

Discuss microprocessors, including

specialty processors Describe the different types ofmemory

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Competencies (2 of 2)

Discuss expansion slots and boards

Describe the five principal types ofexpansion buses

Discuss the four standard ports

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Introduction

Speed, capacity, and flexibility determine thepower of microcomputers. Knowledge of acomputers power allows you to make good

buying decisions and to determine if yourcurrent system will run new applications.Competent end users need to understand thebasic principles of how microcomputers are

put together. These principles will becovered in this chapter.

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System Unit

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System Unit Types

Desktop System Units

Notebook System Units

Tablet PC System Units

Handheld Computer

System Units

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Electronic Data and Instructions

Data and instructions are representedelectronically

Two-state system orBinary System

Off/on electrical states

Characters represented by 0s (off) and 1s (on)

Bits

Bytes

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Binary Coding Schemes

Three types ofbinary coding schemes

ASCII - American Standard Code for InformationExchange

EBCDIC - Extended Binary Coded DecimalInterchange Code

Unicode handles languages with large numbersof characters

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System Board

Connects all components

Allows communication between devices

Main board ormotherboard

Circuit boardelectronic components

Sockets

Slots Bus lines

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Microprocessor

Central Processing Unit (CPU)

Two Basic Components

Control unit

Arithmetic-logic unit (ALU)

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Microprocessor Chips

Chip capacities are expressed in word sizes

Two Recent Significant Developments

64-bit processors

Becoming more commonplace

Windows XP Professional X64 Edition

Dual-Core Chips

Can provide two separate and independent CPUs

Parallel processing

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Specialty Processors

Coprocessors Designed to improve specific computing operations Graphics coprocessors

Smart cards Credit card sized with an embedded chip Used by many universities

RFID tags Information chips Used for tracking purposes

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Memory

Holding area for data, instructions, andinformation

Memory is contained on chips connected to

the system board

Types of memory chips

RAM

ROM CMOS

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RAM

Random Access Memory (RAM) chips holdthe program and data

Cache memory or RAM cache

Flash RAM orflash memory

Other types of RAM

DRAM

SDRAM

DDR

Direct RDRAM

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ROM

Read-only memory (ROM) chips are notvolatile and cannot be changed by the user

CPU can read, or retrieve data and programs

but the computer cannot write

Contain special instructions

Needed to start a computer

Give keyboard keys their special capabilities Put characters on screen

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CMOS

Complementary metal-oxides semiconductor(CMOS) chips provide flexibility for acomputer system

Contains essential information every time thecomputer is turned on Date and time

Amount of RAM

Type of keyboard Content can be changed to reflect changes in

the computer system

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System Clock

Important measurement indicating speed

Located on a small chip

Produces electrical beats

Synchronizes operations Expressed in gigahertz (GHz)

(billions of beats per second)

Fasterclock speed, faster computer

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Expansion Slots and Cards

Allow for new devices to be added

Open architecture

Slots provide for expansion

Expansion cards are also called Plug-in boards

Controller cards

Adapter cards

Interface cards

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Commonly Used Expansion

Cards Graphics cards Sound cards

Modem cards

Network interface cards (NIC)

PC cards (PCMCIA cards)

TV tuner cards

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TV Tuner Cards AndVideo Clips

Allows you to view your favorite TV showswhile running other applications such asExcel

Video can be captured to a file, added to aWeb page, attached to an email, or added toa class presentation

Relatively inexpensive and

easy to install

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Plug and Play

Set of hardware and software standardsdeveloped by Intel, Microsoft, and others

Creating devices that are able to configurethemselves when installed

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Bus Lines

Connect parts of the CPU to each other

Data roadway for traveling bits

Measured as bus width

More lanes, faster traffic

Two basic categories

System buses

Expansion buses

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Expansion Buses

Connects the CPU to other components onthe system board, including expansion slots

Principal types

Industry Standard Architecture (ISA)

Peripheral Component Interconnect (PCI)

Accelerated Graphics Port (AGP)

Universal serial bus (USB)

FireWire buses (HPSB)

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Ports

Socket for connecting externaldevices

Ports can connect directly to

the system board or they canconnect to cards that areinserted into slots on thesystem board

Two Types

Standard Ports

Specialized Ports

Ports

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Standard Ports

Four common ports

Serial ports

Parallel ports

USB ports

FireWire ports

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Specialized Ports

Three specialized ports

Musical Instrument digital interface (MIDI)

Infrared data association (IrDA)

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Cables

Used to connect exterior devices to thesystem unit via the ports

One end of the cable is attached to the

device and the other end has a connectorthat is attached to a matching connector onthe port

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Power Supply

Computers require direct current (DC)

DC power provided by converting alternatingcurrent (AC) from wall outlets or batteries

Desktop computers use power supply units

Notebooks and handhelds use AC adapters

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Careers In IT

Computer technicians repair and installcomputer components and systems

Employers look for

Certification in computer repair

Good communication skills

Continued education is required

Computer technicians can expect to earn anhourly wage of $13.00 to $22.00

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A Look to the FutureXybernaut Corporation

Wearable computers

Send and receiveemail

Maintain yourpersonal schedulebook

Play interactivegames and surf theWeb from anywhere

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Discussion Questions

Describe the four basic types of systemunits.

Describe the two basic components of the

CPU. What are the differences and similarities

between the three types of memory?

Identify five expansion cards and describe

the function of each. Identify and describe four standard ports and

two specialized ports.

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edp 111c chapter 6

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