Computers Are Your Future Twelfth Edition

Computers Are Your FutureTwelfth EditionChapter 2: Inside the System Unit

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall

1*07/16/96*##Inside theComputer SystemCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall2

*07/16/96*##Objectives Understand how computers represent data.Understand the measurements used to describe data transfer rates and data storage capacity.List the components found inside the system unit and explain their use.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall3*07/16/96*##Objectives List the components found on the computers motherboard and explain their role in the computer system.Discuss (in general terms) how a CPU processes data.Explain the factors that determine a microprocessors performance.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall4*07/16/96*##Objectives List the various types of memory found in a computer system and explain the purpose of each.Describe the various physical connectors on the exterior of the system unit and explain their use.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall5*07/16/96*##How Computers Represent DataBinary numbersOnly 0s and 1sBitSmallest piece of data a computer can work withEither on or off, a 0 or a 1Eight bitsbytea single unit of storage

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall6*07/16/96*##How Computers Represent DataModems data transfer rate is in bits per secondExamplegigabits per second (Gbps)Data storage is in bytesKilobyte (KB)one thousand bytesMegabyte (MB)one million bytesGigabytes (GB)one billion bytesTerabyte (TB)one trillion bytes

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall7*07/16/96*##How Computers Represent DataComputers convert binary numbers into hexadecimal (hex) numbersWhich use the numbers 0 through 9, followed by letters A through FCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall8*07/16/96*##How Computers Represent DataFloating point notation Has no fixed number of digits before or after a decimal pointEnables a computer to work quickly with very large or small numbersRequires special processing circuitryCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall9*07/16/96*##How Computers Represent DataCharactersLetters, numbers, and symbolsconverted into numbers the computer understandsCharacter codePerforms the conversionAmerican Standard Code for Information Interchange (ASCII)Extended Binary Coded Decimal Interchange Code (EBCDIC)UnicodeCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall10*07/16/96*##Introducing theSystem UnitSystem unitCase that contains the major hardware components of a computerCome in different stylesFootprintsAmount of space that the unit usesCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall11*07/16/96*##Introducing theSystem UnitSystem unit (cont.)Some have embedded biometric authentication devices such as fingerprint readers, retina scanners, and face recognition systems to prevent unauthorized access.Form factorspecifies how the internal components are located within the system unit.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall12*07/16/96*##Inside the System UnitCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall13

*07/16/96*##MotherboardCPUPower supplyCooling fanInternal speakerDrive baysExpansion slots

System unit main componentsInside the System UnitCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall14*07/16/96*##Inside the System UnitCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall15

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Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall16Inside the System Unit*07/16/96*##Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall17Whats on theMotherboard?

*07/16/96*##MotherboardPrinted circuit board that contains the electrical circuitry for the computerThe majority of parts found on the motherboard are integrated circuits.Includes millions of transistors and carries electrical currentA switch that is able to control the electrical signal flow to the circuit

Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall18*07/16/96*##Whats on theMotherboard?Central processing unit (CPU)Integrated circuit chip that processes electronic signalsAlso known as a microprocessor or processorCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall19*07/16/96*##Whats on theMotherboard?CPU (cont.)Is usually covered by a heat sinkA heat-dissipating component that drains heat from the chipInstructionAn operation performed by the CPU and assigned a specific numberInstruction setThe list of CPU instructions for the operationsCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall20*07/16/96*##Whats on theMotherboard?CPU (cont.)Control unitone of the two main partsRetrieves instructions from memoryInterprets and performs those instructionsManages the machine cycle or processing cycle, the four-part process performed by the CPUArithmetic logic unit (ALU)one of the two main partsPerforms arithmetic and logical operations Involve adding, subtracting, multiplying, dividingLogical operations involve comparisons between two or more data items.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall21*07/16/96*##Whats on theMotherboard?Machine cycleInstruction cycleFetch: Retrieves program instructionsDecode: Determines what the program is telling the computer to doExecution cycle:Execute: Performs the requested actionStore: Stores the results to an internal registerRegistersstore data when it must be temporarily stored in the CPUCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall22*07/16/96*##Whats on theMotherboard?

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall23*07/16/96*##Factors that affect the performance of a CPU include:Number of existing transistorsData bus width and word sizeClock speedOperations per microprocessor cycleUse of parallel processingType of chipWhats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall24*07/16/96*##Data busGroup of parallel wires that connect the CPUs internal componentsWidth measured in bitsMaximum number of bits the CPU can process at once is called the word sizeDetermines which operating systems and software a CPU can runWhats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall25*07/16/96*##Whats on theMotherboard?System clockElectronic circuit that produces rapid pulses and coordinates the computers internal activities.Clock speedmeasurement of the electrical pulses generated by the system clock, usually measured in gigahertz (GHz)Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall26*07/16/96*##Whats on theMotherboard?System clock (cont.)Superscalar architectureenables the CPU to perform more than one instruction for each clock cyclePipeliningenables the CPU to process more than one instruction at a time improving performanceCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall27*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall28

*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall29

*07/16/96*##Whats on theMotherboard?Parallel processingMethod where more than one processor performs at the same timefaster processing

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall30*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall31Multi-core processing Access time reduced Processing time improvedEach core handles incoming streams of data or instructions at the same timeTwo basic types:Dual coreQuad core

*07/16/96*##ChipsetSet of chips that supply the switching circuitry the CPU requires to move data throughout the computerThe CPU and the input/output (I/O) bus linked through the chipsetProvides a means to communicate with input and output devicesWhats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall32*07/16/96*##MemoryChips on the motherboard or within the CPU that retain instructions and dataRandom access memory (RAM)Temporarily stores data and instructions for the CPUVolatilecontents erased after computer is shut offAllows CPU to access or store data and instructions quickly through RAMs memory address featureIdentifies and locates stored dataWhats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall33*07/16/96*##Whats on theMotherboard?

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall34*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall35RAM (cont.)Comes in the form of memory modules or memory cardsMemory modules (memory cards)small circuit boards that hold several RAM chips and fits into special slots on the motherboardTypes of RAM:Dual inline memory modules (DIMM)most common today 168-pin connector 64-bit transfer rateSingle inline memory modules (SIMM)older technology72-pin connector32-bit transfer rate*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall36Memory footprintAmount of RAM the operating system uses while it operatesVirtual memorySection of the hard drive set aside to use when RAM gets full*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall37Cache memorySmall unit of ultrafast memory built into or near the processorUsed to store frequently or recently access program instructions or dataFaster than RAMMore expensive than RAMThree levels of cache on a system:Level 1 (L1) cache (primary cache)Level 2 (L2) cache (secondary cache)Level 3 (L3) cacheFound on some newer microprocessorsPrimarily used in servers and workstations*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall38

*07/16/96*##Read-only memory (ROM)Contains prerecorded instructions to start the computerNonvolatilecontents stored when CPU power offBasic input/output system (BIOS)First code run when the system is powered onBootstrap loaderProgramlocates and loads the operating system into RAMComplementary metal-oxide semiconductor (CMOS)Starts the power-on self-test and verifies other system components are operating correctlyPower-on self-test (POST)Checks circuitry and RAM, marking defective locationsWhats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall39*07/16/96*##Whats on theMotherboard?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall40ROM (cont.)Programmable ROM (PROM) Electrically-PROM (EPROM)Electrically erasable PROM (EEPROM)Flash EPROM

*07/16/96*##Whats on the Outside of the Box?Front panelPower switchUsed to turn the computer onDrive activity lightAdvises the user that the hard drive is retrieving dataPower-on lightShows whether the power is onCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall41*07/16/96*##Whats on the Outside of the Box?Outside a system unitConnectorphysical receptacle used to plug a peripheral device into the computerExample: telephone jackPortelectronically defined pathway used to send data into and retrieve data from the computerExample: USB port

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall42*07/16/96*##Whats on the Outside of the Box?

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall43*07/16/96*##Whats on the Outside of the Box?Connectors on a notebook may varyCopyright 2012 Pearson Education, Inc. Publishing as Prentice Hall44

This is Figure 2.29.*07/16/96*##Whats on the Outside of the Box?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall45USB (universal serial bus) portsConnects up to 127 peripheral devicesUSB 2.0 (high-speed USB)fully compatible with USB 1.1 products, cables, and connectorsDesigned to replace older parallel and serial portsConnects a variety of devices to the computer, including:KeyboardsMicePrintersDigital cameras

*07/16/96*##Whats on the Outside of the Box?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall46USB 2.0 Uses an external busSupports data transfer rates of 480 Mbps between the computer and the peripheral deviceSupports hot swappingability to connect and disconnect devices without shutting down the computerPlug-and-play (PnP)allows computers to automatically detect the device when you plug it inUSB hubDevice that plugs into existing USB portContains four or more additional portsThis is Figure 2.20.*07/16/96*##Whats on the Outside of the Box?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall47FireWire (1395 ports)Created by Apple in 1995IEEE 1394 Higher Performance Serial Bus, also known as Sony i.LinkOffers high-speed connections for dozens of peripheral devices (up to 63)Enables hot swapping and PnPData transfer rates of FireWireFireWire 400400 MbpsFireWire 800800 MbpsFireWire S3200next generation (expected to transfer data at 3.2 Gbps)This is Figure 2.20.*07/16/96*##Whats on the Outside of the Box?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall48Video connectorsVGA (video graphics array)15-pin male connectorworks with standard monitor cablesTransmits analog video signals Used for legacy technology cathode ray (CRT) monitorsDVI (Digital visual Interface) portlets LCD monitors use digital signalsOnboard videovideo circuitry built into the motherboard where the video connector is on the back of the system unit caseThis is Figure 2.20.*07/16/96*##Whats on the Outside of the Box?Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall49Additional connectorsTelephoneNetworkPC card slotPC cardExpressCardSound cardGame cardTV/sound capture board*07/16/96*##Whats on the Outside of the Box?Legacy technologyOlder technology that is being phased outExamples:Serial portsParallel portsPS/2 ports SCSI (small computer system interface) ports

Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall50*07/16/96*##SummaryUnderstand how computers represent data.Understand the measurements used to describe data transfer rates and data storage capacity.List the components found inside the system unit and explain their use.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall51*07/16/96*##SummaryList the components found on the computers motherboard and explain their role in the computer system.Discuss (in general terms) how a CPU processes data.Explain the factors that determine a microprocessors performance.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall52*07/16/96*##SummaryList the various types of memory found in a computer system and explain the purpose of each.Describe the various physical connectors on the exterior of the system unit and explain their use.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall53*07/16/96*##

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America.Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall54Copyright 2012 Pearson Education, Inc. Publishing as Prentice Hall