Components of a System Unit

8/21/2019 Components of a System Unit

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Living in a Digital World

Discovering

Computers 2010


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Objectives Overview

Differentiate among variousstyles of system units on

desktop computers,

notebook computers, andmobile devices

Identify chips, adaptercards, and othercomponents of a

motherboard

Describe the control unitand arithmetic logic unit

components of a processor,

and explain the four steps ina machine cycle

Identify characteristics ofvarious personal computer

processors on the markettoday, and describe the

ways processors are cooled

Define a bit and describe

how a series of bitsrepresents data

Explain how program

instructions transfer in andout of memory

Discovering Computers 2010: Living in a Digital World

Chapter 42See Page 209

for Detailed Objectives


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Objectives Overview

Differentiate among the varioustypes of memory

Describe the purpose and typesof expansion slots and adaptercards, and differentiate among

slots for various removable flashmemory devices

Differentiate between a port anda connector, and explain the

differences among a USB port,FireWire port, Bluetooth port,

SCSI port, eSATA port, IrDA port,serial port, and MIDI port

Describe the types of buses in acomputer

Explain the purpose of a power

supply and describe how it keepscool

Understand how to clean a

system unit on a computer ormobile device


Chapter 43See Page 209

for Detailed Objectives


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The System Unit

• The system unit is a case that contains electronic

components of the computer used to process data


Chapter 44Page 210

Figure 4-1


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The System Unit

• The inside of the system unit on a desktop

personal computer includes:


Chapter 45Page 211

Figure 4-2

Drive bay(s)

Power supply

Sound card

Video card

Processor

Memory


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The System Unit

• The motherboard is the main circuit board of the

system unit

– A computer chip contains integrated circuits


Chapter 46Page 212

Figure 4-3


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Processor

• The processor, also called the central processing

unit (CPU), interprets and carries out the basic

instructions that operate a computer

– Contain a control unit and an arithmetic logic unit

(ALU)


Chapter 47Page 213

Multi-coreprocessor

Dual-coreprocessor

Quad-coreprocessor


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Processor


Chapter 48Page 213

Figure 4-4


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Processor

• The control unit is the component of the

processor that directs and coordinates most of

the operations in the computer

• The arithmetic logic unit (ALU) performs

arithmetic, comparison, and other operations


Chapter 49Page 214

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Control Unitbelow Chapter 4

http://www.scsite.com/dc2010cp/ch4/weblink/


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Processor

• For every instruction, a processor repeats a set of

four basic operations, which comprise a machine

cycle


Chapter 410Page 215

Figure 4-5


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Processor

• Most current personal

computers support

pipelining

–Processor beginsfetching a second

instruction before it

completes the machine

cycle for the first

instruction


Chapter 411Pages 215 – 216

Figure 4-6


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Processor

The processor contains registers, thattemporarily hold data and instructions

The system clock controls the timing

of all computer operations• The pace of the system clock is called the clock

speed, and is measured in gigahertz (GHz)


Chapter 412Page 216


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Processor

• The leading

manufacturers of

personal computer

processor chips are Inteland AMD



Figure 4-7

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Multi-CoreProcessors below Chapter 4



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Processor

• Determine how you plan to use a new computer

before selecting a processor


Chapter 414Page 218

Figure 4-8


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Processor

• A processor chip

generates heat that

could cause the chip to

burn up• Require additional

cooling

– Heat sinks

– Liquid cooling

technology


Chapter 415Pages 219 - 220

Figures 4-9 – 4-10

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Liquid Coolingbelow Chapter 4



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Processor

• Parallel processing uses multiple processors

simultaneously to execute a single program or task

– Massively parallel processing involves hundreds or thousands of

processors


Chapter 416Page 220

Figure 4-11


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Data Representation

Analog signals are continuous and vary instrength and quality

Digital signals are in one of two states: onor off

• Most computers are digital

• The binary system uses two unique digits (0 and 1)

• Bits and bytes


Chapter 417Page 221


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Data Representation

A computer circuit representsthe 0 or the 1 electronically bythe presence or absence of anelectrical charge

Eight bits grouped together as aunit are called a byte. A byterepresents a single character inthe computer


Chapter 418Page 221

Figures 4-12 – 4-13


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Data Representation

• ASCII (American

Standard Code for

Information

Interchange) is the mostwidely used coding

scheme to represent

data


Chapter 419Page 221

Figure 4-14


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Data Representation


Chapter 420Page 222

Figure 4-15


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Memory

• Memory consists of electronic components that

store instructions waiting to be executed by the

processor, data needed by those instructions, and

the results of processing the data

• Stores three basic categories of items:


Chapter 421Page 223

The operatingsystem and othersystem software

Applicationprograms

Data beingprocessed and theresulting

information


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Memory

• Each location in memory has an address

• Memory size is measured in kilobytes (KB or K),

megabytes (MB), gigabytes (GB), or terabytes

(TB)


Chapter 422Page 223

Figure 4-17


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Memory

• The system unit contains two types of memory:



Volatile memory

Loses its contents whenpower is turned off

Example includes RAM

Nonvolatile memory

Does not lose contentswhen power is removed

Examples include ROM,flash memory, and

CMOS


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Memory


Chapter 424Page 224

Figure 4-18


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Memory

• Three basic types of RAM chips exist:


Chapter 425Page 225

Figure 4-19

Dynamic RAM(DRAM)

Static RAM (SRAM)Magnetoresistive

RAM (MRAM)


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Memory

• RAM chips usually reside on a memory module

and are inserted into memory slots


Chapter 426Page 225

Figure 4-20


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Memory

• The amount of RAM necessary in a computer

often depends on the types of software you plan

to use


Chapter 427Page 226

Figure 4-21


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Memory

• Memory cache speeds the processes of the computer

because it stores frequently used instructions and data


Chapter 428Page 227

Figure 4-22

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click WindowsReadyBoost below Chapter 4



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Memory

Read-only memory (ROM) refers to memory chipsstoring permanent data and instructions

• Firmware

A PROM (programmable read-only memory) chip is ablank ROM chip that can be written to permanently

• EEPROM can be erased


Chapter 429Page 228

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click ROMbelow Chapter 4



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Memory

• Flash memory can be erased electronically and

rewritten

– CMOS technology provides high speeds and consumes

little power



Figure 4-23


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Memory

• Access time is the amount of time it takes the

processor to read from memory

– Measured in nanoseconds


Chapter 431Page 229

Figures 4-24 – 4-25


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Expansion Slots and Adapter Cards

• An expansion slot is a

socket on the motherboard

that can hold an adapter

card

• An adapter card enhancesfunctions of a component of

the system unit and/or

provides connections to

peripherals – Sound card and video card


Chapter 432Page 230

Figure 4-26

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Video Cardsbelow Chapter 4



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• With Plug and Play, the computer automatically

can configure adapter cards and other peripherals

as you install them



Figure 4-27


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• Removable flash memory includes:

– Memory cards, USB flash drives, and PC

Cards/ExpressCard modules


Chapter 434Page 231

Figure 4-28


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Ports and Connectors

A port is the point at which a peripheral attaches to orcommunicates with a system unit (sometimes referred

to as a jack)

A connector joins a cable to a port


Chapter 435Page 232

Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Digital Audio Portbelow Chapter 4



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Chapter 436Page 232

Figure 4-29


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• On a notebook computer, the ports are on the

back, front, and/or sides



Figure 4-30


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Discovering Computers 2010: Living in a Digital WorldChapter 4

38Page 233Figure 4-31


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• A USB port can connect up to 127 different

peripherals together with a single connector

– You can attach multiple peripherals using a single USB

port with a USB hub



Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click USB Portsbelow Chapter 4



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• Other types of ports include:


40Pages 234 - 236

Firewireport

Bluetooth port

SCSI port

eSATAport

IrDA port Serial port

MIDI port


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A Bluetooth wireless port

adapter converts a USB port into

a Bluetooth port

A smart phone might

communicate with a notebook

computer using an IrDA port


41Page 235Figures 4-33 – 4-34


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• A port replicator is an

external device that

provides connections to

peripherals through ports

built into the device• A docking station is an

external device that

attaches to a mobile

computer or device



Click to view Web Link,click Chapter 4, Click WebLink from left navigation,then click Docking Stationbelow Chapter 4



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Buses

• A bus allows the variousdevices both inside andattached to the systemunit to communicate with

each other – Data bus

– Address bus

• Word size is the number

of bits the processor caninterpret and execute at agiven time




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Buses

• Expansion slots connect to expansion buses

• Common types of expansion buses include:


44Page 238

PCI bus PCI Expressbus

AcceleratedGraphics Port

USB andFireWire bus

PC Card busClick to view Web Link,click Chapter 4, Click WebLink from left navigation,then click FireWirebelow Chapter 4



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Bays

• A bay is an opening

inside the system unit in

which you can install

additional equipment – A drive bay typically

holds disk drives




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Power Supply

The power supply

converts the walloutlet AC power into DC power

Some external peripherals have an AC

adapter, which is an external powersupply


46Page 239


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Putting It All Together

Home

Intel Core 2 Duo or IntelCeleron Dual Core or

AMD Sempron

Minimum RAM: 2 GB

Small Office/Home Office

Intel Core 2 Quad orIntel Core 2 Extreme or

AMD Athlon FX or AMDAthlon X2 Dual-Code

Minimum RAM: 4 GB

Mobile

Intel Core 2 Extreme orAMD Turion X2

Minimum RAM: 2 GB




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Putting It All Together

Power

Intel Itanium 2 or AMDQuad Core Opteron or

Intel Quad Core Xeon orSun UltraSPARC T2

Minimum RAM: 8 GB

Enterprise

Intel Core 2 Quad orIntel Core 2 Extreme orAMD Athlon FX or AMD

Athlon X2 Dual-Core

Minimum RAM: 4 GB



Keeping Your Computer


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Keeping Your Computer

or Mobile Device Clean

Clean your computer or mobile device once or twice a year

Turn off and unplug your computer or mobile device beforecleaning it

Use compressed air to blow away dust

Use an antistatic wipe to clean the exterior of the case and acleaning solution and soft cloth to clean the screen


49Page 240


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Video: The Leopard with a Time Machine


50

CLICK TO START

http://localhost/var/www/apps/conversion/tmp/scratch_5/04_timemachine.wmvhttp://localhost/var/www/apps/conversion/tmp/scratch_5/04_timemachine.wmvhttp://localhost/var/www/apps/conversion/tmp/scratch_5/04_timemachine.wmv


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Summary

Components of thesystem unit

How memory storesdata, instructions, and

information

Sequence of operationsthat occur when a

computer executes an

instruction

Comparison of variouspersonal computerprocessors on the

market today

How to clean the

exterior and interior ofa system unit


51Page 241


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Discovering

Computers 2010

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Components of a System Unit