《計算機(jī)英語》計算機(jī)英語第二章

計算機(jī)英語Chapter2ComputerSystemOrganization11CPU目錄2MemorySubsystemCONTENT3I/OSubsystem2almostallmoderncomputers,eachmemorycellisset本句為并列復(fù)合句，后邊的分句省略與usersaddhigher-qualityReadingMaterialonlytheusercanhearthesoundfromthecomputer.OtherI/ODevicesBecausetheyrequirealotofarmdigitally,insteadlightsource,aintoanaudiocomputerandsoftwarethesoul.在計算機(jī)中布爾邏輯定義若干布爾邏輯函Comparedwith[in's??t;'ins??t]Itisusuallydividedintothreeprimarysubsystems:theCPU,thememoryLeadinAcomputersystemconsistsofhardwaresystemandsoftwaresystem.withoutsoftware,hardwareinformation.Hence,hardwareisthebodyofthecomputerandsoftwarethesoul.[1]InandsoftwarewillbeillustratedinHardwareisthematerialfoundationofthecomputer,butcannotbeinstructedtoprocessdataintothischapter,wemainlyintroducethecomputerhardwarethefollowingchapter.Computerhardwareistheequipmentinvolvedinthefunctionofacomputerandconsistsofthecomponentsthatcanbephysicallyhandled.Itisusuallydividedintothreeprimarysubsystems:theCPU,thememorysubsysteminterconnectedbybuses,oftenmadeofgroupsofwires.andtheinput/output(I/O)subsystem.Thesethreepartsare31CPU41CPUThecomputer'scentralprocessingunit(CPU)istheelectroniccircuitrythatprovidesthecomputationalabilityandcontrolofthecomputer.Internally,theCPUhasthreesections,asshownin2-1.Figure51CPU1ArithmeticandLogicUnitAsitsnameimplies,thearithmeticandlogicunit(ALU)performstwoclassesofoperations:arithmeticaddition,subtraction,multiplicationanddivision.AnycomputercanprogrammedinvolveBooleanlogic[2]:AND,OR,XORandNOT.ThesecanbeusefulbothforcreatingcomplicatedconditionalstatementsandprocessingBooleanlogic.Mostcomputerscanalsoperformandlogic.Arithmeticoperationsincludebetoperformanyarithmeticoperation.Logicoperationscertainlogicoperationsonwords.Astheabovediagramshows,theALUreceivesitsoperandsfromtheregistersetoftheCPUandstoresitsresultsbackinperformswhateverarithmeticorlogicoperationsarerequiredtohelpouttheinstructions.theregisterset.Itcarry61CPU2ControlUnitThecontrolunit,oftencalledacontrolsystem,isafunctionalunitsupervisingtheoperationoftheentireconnectionsbetweenvariousfunctionalunitsofthecomputersysteminterpretsinstructionsincomputersystem.Itmakestheandtheprogramonebyone.Thecontrolunitfetchesinstructionsfrommemoryanddeterminestheirtypesordecodesthem.Itthenbreakseachinstructionintoaseriousofcontrolsignalssystemsinsooperationsthatthecontrolunitgoesthroughtointhatoperatetheotherpartsofthecomputer.Controladvancedcomputersmaychangetheorderofsomeinstructionsimproveastoperformance.It'snoticeablethatthesequenceofprocessaninstructionisitselflikeashortcomputerprogram.[3]71CPU3RegisterSetTheregistersetstoresintermediatedatausedduringtheexecutionoftheinstructions,whichincludesasetofregistersandabusorothercommunicationmechanism.AregisterisaquicklyaccessiblelocationavailabletoaCPU.Itcanbereadandwrittentohavingconsistentlygreatlyalargermemoryintoregisterswhereitisusedforarithmeticoperationsandismanipulatedortestedbyinstructions.Manipulateddataisbacktomainmuchmorerapidlythanthemainmemoryarea,whichavoidstoaccessmainmemoryeverytimedataisneeded.Sincedataisbeingworkedon,reducingtheneedtoaccessmainmemoryincreasesthecomputer'sspeed.[4]Almostallcomputersloaddatafromthenoftenstoredmemory.82MemorySubsystem92MemorySubsystemMemory,alsoknownasinternalmemoryormainmemory,referstothecomputerchipsthatstoreinformationforquickretrievalbytheCPU.Acomputer'smemorycanbeviewedasalistofcellsintowhichnumberscanbeplacedorread.Inuptocanstorerepresentedtrillionsofbytesofmemory.almostallmoderncomputers,eachmemorycellissetgroupsofeightbits,calledabyte.Acomputerstorebinary[5]numbersinanykindofinformationinmemoryaslongasitcanbesomehowinnumericalform.[6]ModerncomputershavebillionsorevenAcomputer'smainmemorycomesintwoprincipalvarieties:randomaccessmemory(RAM)andread-onlymemory(ROM).102MemorySubsystemRAMRAMisusedtostoretheinformationandinstructionsthatoperatethecomputer'sprograms.ItisaccessiblecircuitrywheretheCPUcanrunprogramsandprocessdata.AllthedatatypedintothecomputergoesdirectlytoRAM.essentialtoacomputerbecauseitprovidesrapidlyThecomputer'sRAMsizelargelydetermineshowmanyprogramsmayrunsimultaneouslymemory,complicatedprogramswillrunslowlyorwon'trunatall.withoutperformancedegradation.IfthecomputerhastoolittleRAMisalsoknownasvolatilememorybecausetheinformationwithinthecomputerchipsispermanently,itisnecessarytocopythedatatoasecondarystoragedevicesuchasadisk.erasedassoonasthecomputerisswitchedoff.Tokeepdata112MemorySubsystemRAMcanbefurthercategorizedintoastaticrandomaccessmemory(SRAM)andadynamicrandomaccessmemory(DRAM).InSRAM,theword“static”indicatesthatthememoryretainsitscontentsaslongaspowerisbeingsupplied.However,dataislostwhenthepowergetsdownduetoitsvolatilenature.SRAMchipsuseamatrixof6-transistors.DRAM,unlikeSRAM,mustbeperiodicallyrefreshedinordertomaintainthedata.Thisisdonebyplacingthememoryonarefreshcircuitthatrewritesthedataseveralhundredcomposedofonecapacitorandonetransistor.timespersecond.AllDRAMsaremadeupofmemorycellswhichareBecauseoftheextraspaceinthematrix,SRAMusesmorechipsthanDRAMforthesameamountofstoragespace,thusmakingthemanufacturingcostshigher.SoSRAMandsmaller,DRAMisusedformostsystemisusedascachememoryandhasveryfastaccess.Incontrast,beingcheapermemory.122MemorySubsystemROMAsitsnameimplies,datastoredinROMcannotbeoverwrittenbutreadonly.Itcontainscriticalinformationandsoftwarethatmustbepermanentlyavailableforcomputeroperation.Itisalsoknownasnonvolatiletheirmemorybecausethememorychipsdonotlosecomputeristurnedon,thepermanentsoftwareininformationwhenthecomputerpowerisoff.WhentheROMbootsthecomputer.ROMchipscanbefurthercategorizedintoprogrammablereadonlymemoryandelectricallywhicharedifferentiatedbyhowandhowoftentheycanbeprogrammed.(PROM),erasableandprogrammablereadonlymemory(EPROM)erasableandprogrammablereadonlymemory(EEPROM),132MemorySubsystemPROMcanbemodifiedonlyoncebyauser.TheuserbuysablankPROMprogram.InsidethePROMandentersthedesiredcontentsusingaPROMchipbeprogrammedonlyonceandisnoterasable.therearesmallfuseswhichareburntopenduringprogramming.ItcanEPROMcanbeerasedbyexposingittoultravioletlightforadurationofuptofortyminutes.Usually,anEPROMeraserachievesthisfunction.Duringprogramming,anelectricalchargeistrappedinchargeisretainedformorethantenyearsbecausethechargehasnoleakagepath.Forerasingthiscrystalwindow.Thisexposuretoultravioletlightdissipatesthecharge.aninsulatedgateregion.Thecharge,ultravioletlightispassedthroughaquartz142MemorySubsystemEEPROMisprogrammedanderasedelectrically.Itcantimes.Botherasingandprogrammingtakeabout4to10ms(milliseconds).selectivelyerasedonebyteatatime,ratherthanerasingtheentirechip.Hence,theprocessofreprogrammingisflexiblebutslow.beerasedandreprogrammedabouttenthousandInEEPROM,anylocationcanbebeerasedandprogrammed.EEPROMscan153I/OSubsystem163I/OSubsystemI/Oisthemeansbywhichacomputerreceivesinformationresultsback.Devicesthatprovideinputoroutputtothecomputerarepersonalcomputer,peripheralsthekeyboardmonitorandprinter.Storagedevicessuchdisks,floppydisksandinputsformfromtheoutsideworldandsendscalledperipherals.Onatypicalincludeinputslikeandmouse,andoutputssuchastheashardbothanothercompactdisksserveandoutputs.ComputernetworkisofI/O.173I/OSubsystem1InputDevicesAninputdeviceallowsausertoenterdataandcommandsintothememoryofacomputer.Belowarecommonlydevices.usedinput183I/OSubsystem1InputDevices1KeyboardThekeyboardisoneofthemaininputdevicesforacommonlykeysthatallownumbers,spaces,punctuationmarksorothersymbols.Itperformcomputersystem.Itisthewayauserwillmostcommunicatewithtypelettersofthealphabet,acomputer.Itcontainstypelettersofthealphabet,userstoalsocontainsspecificfunctionsonthecomputer.specialkeysthatallowusersto193I/OSubsystem1InputDevices2MouseAmouseisapointingdevicedesignedtobegripped(usuallycontrolthemotionofanon-screenpointer,orcursor,bymovingthemouseonaflatsurface.Themouseapparentlysizeandformkindofmousehastwobuttonsontopwithonebeingusedmorefrequently.byonehand.Ithasadetectiondeviceaball)onthebottomthatenablesuserstogetsitsnamebybeingaboutthesameasatoymouse.Themostconventionaltheleft203I/OSubsystem1InputDevices3ScannerAscanneruseslight-sensingequipmenttointoconvertelectroniccomputercommontypesofscanneraretheflatbedscanner,whichissimilartohand-heldacrosstheimagetobeprocessed.imagessuchaspictureortextsignalsthatcanbemanipulatedThebyawithinseveralminutes.twoanofficephotocopier,andthescanner,whichispassedmanually213I/OSubsystem1InputDevices4ModemAmodem,whichstandsformodulator-demodulator,isusedforcommunicatingbetweencomputers.ItconnectsacomputertobeWhencomputerisconvertedbythemodemwhichreceivingmodem.Thenintocomputer.atelephonelineandallowsinformationtotransmittedtoorreceivedfromanothercomputer.transmitting,theinformationsentfromoneintoanaudiosignal,isthentransmittedbythetelephonelinetothethismodemconvertsthesignalinformationthatcanbeunderstoodbythereceiving223I/OSubsystem1InputDevices5MicrophoneAmicrophoneisadeviceforconvertingsoundintobestored,manipulated,andplayedbackbythecomputer.moduleisadevicethatconvertsspokenwordscomputercanrecognizeandprocess.signalsthatcanAvoicerecognitionintoinformationthatthe233I/OSubsystem2OutputDevicesOutputdevicestransmittheresultsprocessedbythecomputertocommonlyusedoutputdevices.theoutsidecomponentsfortheuser.Beloware243I/OSubsystem2OutputDevices1MonitorMonitors,commonlycalledasVisualDisplayUnit(VDU),arethemainpixelsthatarearrangedindependsuponthenumberofpixels.outputdeviceofacomputer.Itformsimagesfromtinydots,calledarectangularform.ThesharpnessoftheimageTherearetwokindsofviewingscreenusedformonitors.Oneisacathoderaytube(CRT)andtheotherisaflat-paneldisplay.ACRT-basedscreenlookssimilartoatelevisionset.InformationofelectronsthatscansafromphosphorescentHowever,CRTmonitorsvoltageimages.theCPUisdisplayedusingabeamhighsurfacethatemitslightandcreatesimages.higharebulkyandtheyrequirearelativelypowersupplytosufficientlyelectronbeamsfordisplaying253I/OSubsystem2OutputDevicesTheflat-paneldisplayreferstoaclassofvideodevicesthathavereducedvolume,weightandpowerrequirementinofflat-paneldisplayscomputer,graphicsdisplay.comparisontotheCRT.Currentusesincludecalculators,videogames,monitors,laptopTheflat-paneldisplayisdividedintotwocategories:emissivedisplaysandnon-emissivelight.Examplesareemissivedisplaysuseopticaleffectstoothersourcesintoexample.displays.TheemissivedisplaysconvertelectricalenergyintoplasmapanelsandLED(light-emittingdiodes).Thenon-convertsunlightorlightfromsomegraphicspatterns.ALCD(liquidcrystaldisplay)isatypicalFiguresbelowrespectivelyshowaCRTmonitorandaflat-panelmonitor.263I/OSubsystem2OutputDevices2PrinterThesecondtypeisanink-jetprinter.Itfiresdropletsofinkontoapagetoacceptanceamongconsumersinprintingwithhighresolutionandrelativelyinexpensive.formcharactersandpictures.InkjetprintinghasgainedwidetheprintingindustrybecauseitisfastinThelasttype,laserprintersareofthehighestquality.Theyemploybeamsoflighttoparticlescalledtoner.ThetonerisfusedtoThelaserprinterhasadvantageousoperatingcharacteristicsoflownoise,highspeedandhighresolution.drawimagesonadrumthatthenpicksupfineblackapagetoproduceanimage.273I/OSubsystem2OutputDevicesAprinterisanimageformationdevicewhichreceivesdatafromahostcomputerandthenformsacorrespondingimageontomediumsuchasasheetofpaper.Therearethreemajortypesofprinters.arecordableDot-matrixprintersfeatureamovableprintheadcontainingarowoftinypins.Thepinspushaninkedribbonagainstthepaper,producingamatrixthedotscanformthedot-matrixwithdocumentinofdots.Astheprintheadmovesbackandforthacrossthepage,eitherlettersorgraphics.Comparedwithothertypes,printerislessexpensivebutproduceslowerresolutioncopiesofanoise.However,asitusespins,itcanproducemultipleasingleprinting,whichisuniqueamongothers.283I/OSubsystem2OutputDevices3AudioOutputDevicesAudiooutputdevicesarethecomponentsofacomputerthatproducemusic,speech,orothersounds.Twocommonlyusedaudiospeakersandheadsets.outputdevicesareMostpersonalcomputershaveasmallinternalspeakerthatusuallyoutputsusersaddhigher-qualitycanbeeasilyonlytheusercanhearthesoundfromthecomputer.onlylow-qualitysound.Forthisreason,manypersonalcomputerstereospeakers.Whenusingspeakers,theoutputheard.Whenpluggingaheadsetintoaportonthesoundcard,293I/OSubsystem3OtherI/ODevices303I/OSubsystem3OtherI/ODevices1DiskDriveStoragehardwarealsocanberegardedasinputandoutputdevice.Differentfromthemainretrievalbythecomputer.Onecommonlyround,flatpieceofplasticormetalonwhichitemscanbeencoded,orwritten.[7]Adiskdriveisadevicethatreadsfromdrives:hard,floppy,magneto-opticalandcompact.memory,itprovidespermanentstorageofinformationandprogramsforusedstoragemediumisadisk,whichisaandwritesontoadisk.ThereareseveraltypesofdiskAharddiskusuallyconsistsofseveralcirculardisksonwhichdata,instructions,andinformationinformationandretrievethatinformationveryquickly.Somehardwhichmeanstheycanbeinsertedandremovedfromthisisthattheycanbetakenoutofthecomputerandtransportedorsecured.arestoredmagnetically.Harddiskdrivescanstorelargeamountsofdisksareremovable,aharddiskdrive.Theadvantageof313I/OSubsystem3OtherI/ODevicesAfloppydiskconsistsofathin,circular,flexiblediskenclosedinaplasticshell.Italsostoresinformationininformationthanharddiskdrivesandretrievetheinformationatamuchslowerrate.magneticparticlesinremovabledisks.FloppydisksstorelessMagneto-opticaldiskdrivesstoreinformationonremovabledisksthatareasmuchsensitivetoinformationasharddisksbuthaveslightlyslowerretrievalspeeds.bothlaserlightandmagneticfields.TheycantypicallystoreCompactdiskdrives(CD-ROM)storeinformationonpitsburnedintothesurfaceofadiskofreflectivematerial.TheinformationstoredonCD-ROMscannotbeerasedoroverwrittenwithnewinformation.Theycanstoreaboutasmuchinformationasaharddiskdrivebuthaveaslowerrateofinformationretrieval.AvariationofthestandardCD-ROMinformationstoredinistherewritableCD,alsocalledaCD-RW.DifferentfromtheCD-ROM,theCD-RWcanbeerasedandoverwritten.323I/OSubsystem3OtherI/ODevices2DigitalCameraAdigitalcameratoisavideoinputdevice,whichallowsusersdigitally,insteadtheimageiscircuitcomputerandrestoredtocomputer.Digitalcamerashavewideapplicationsbothandbusiness.Itcanbeusedforvideomeeting,telemedicineandreal-timemonitoringaswellasforpersonalvideochatting.takepicturesandstorethephotographedimagesofontraditionalfilm.Whenphotographed,processedandconvertedbythelight-sensitivetothedigitalsignal.Thenthesignalisinputtothethetheimagebysomesoftwareininlife333I/OSubsystem3OtherI/ODevices3DataProjectorAdataprojectortakestheimagethatdisplaysonontoascreensothataudiencecanseetheimageclearly.attachedtocanbesmallportabledevices.acomputerscreenandprojectsitDataprojectorscanbelargedevicesaceilingorwallinanauditoriumor343I/OSubsystem3OtherI/ODevices4TouchScreenAmonitorthathasatouch-sensitivepanelonthescreeniscalledatouchscreen(SeeFigure2-4).Usersinteractwiththecomputerbytouchingareasofthescreenwiththeirfingers.Becausetheyrequirealotofarmscreensarenotusedtoenterlargeamountsofdata.Insteadtheyareusedtotouchwords,pictures,numbers,orlocationsidentifiedonthescreen.Touchscreensarewidelykioskslocatedinlaptopcomputersemploytouchscreensaswell.movements,touchappliedinstores,hotels,airportsandmuseums.Some353I/OSubsystem3OtherI/ODevices5BarcodeReaderAbarcodeisamachine-readablerepresentationattached.ofdataOriginallyvaryingthewidthsandspacingsofparallellines,andmaybereferredtoLatertwo-dimensional(2D)codesusingrectangles,dots,hexagonsandothergeometricpatternsinrelatingtotheobjecttowhichitisbarcodessystematicallyrepresenteddatabyaslinearorone-dimensional(1D).weredeveloped,twodimensions.363I/OSubsystem3OtherI/ODevices5BarcodeReaderAbarcodereader,orbarcodescanner,asshowninFigure2-5,barcodestolightsource,aimpulsesintoreadersimagedataprovidedbythesensorandsendingthebarcode’scontenttogreatmanagement,postalmanagement,etc.isanelectronicdevicethatcanreadandoutputprintedacomputer.Likeaflatbedscanner,itconsistsofalensandalightsensortranslatingopticalelectricalones.Additionally,nearlyallbarcodecontaindecodercircuitryanalyzingthebarcode’sthescanner’soutputport.Barcodereadersgainacceptanceamongcommoditycirculation,book37Words38Wordssubsystem['s?b?sist?m;s?b's-]n.子系統(tǒng)interconnect[?int?k?'nekt]v.互相聯(lián)系bus[b?s]n.總線n.電線n.算法n.加法n.減法n.乘法n.除法wire['wai?]arithmetic[?'riθm?tik]addition[?'di??n]subtraction[s?b'tr?k??n]multiplication[?m?ltipli'kei??n]division[di'vi??n]interpret[in't??prit]v.解讀v.取來v.解碼fetch[fet?]decode[?di?'k?ud]intermediate[?int?'mi?dj?t;-dieit]adj.中間的mechanismretrieval['mek?niz?m]n.機(jī)制[ri'tri?v?l]n.恢復(fù)；取回39Wordscell[sel]n.單元binary['bain?ri]adj.二進(jìn)制的byte[bait]n.字節(jié)numerical[nju?'merik?l]adj.數(shù)值的circuitry['s??kitri]n.電路；電路系統(tǒng)simultaneously[saim?l'teini?sli]adv.同時地degradation[?degr?'dei??n]n.退化；降級permanently['p??m?n?ntli]adv.永久地disk[disk]n.磁盤overwrite[??uv?'rait;'?uv?rait]v.重寫matrix['meitriks]n.矩形periodically[?pi?ri'?dik?li]adv.定期地；周期性地refresh[ri'fre?;ri?-]v.刷新capacitor[k?'p?sit?]n.電容器40Wordsboot[bu?t]v.啟動differentiate[?dif?'ren?ieit]v.區(qū)分fuse[fju?z]n.保險絲n.紫外線ultraviolet[??ltr?'vai?l?t]retain[ri'tein][kw??ts]v.保留quartzn.石英dissipate['disipeit]v.驅(qū)散millisecondperipheral['mili?sek?nd]n.毫秒[p?'rif?r?l]adj.外圍的grip[grip]v.緊握detection[di'tek??n]n.檢測；察覺pointer['p?int?]n.指針；指示器cursor['k??s?]n.光標(biāo)41Wordsscanner['sk?n?]n.掃描儀light-sensingphotocopier[lait-sensi?]adj.感光的[?f?ut?u'k?pi?]n.影印機(jī)manually['m?nju?li]adv.手動地modem['m?udem]n.調(diào)制解調(diào)器audio['??di?u]adj.聲音的recognition[rek?g'ni??n]n.識別module['m?dju?l;-d?u?l]n.模塊；組件monitor['m?nit?]n.顯示屏；監(jiān)視器pixel['piks?l]n.像素rectangular['rek't??gjul?]adj.矩形的sharpness['?ɑ?pnis]n.清晰度electron[i'lektr?n]n.電子phosphorescent[?f?sf?'resnt]adj.磷光性的42Wordsemit[i'mit]v.發(fā)出；放射bulky['b?lki]adj.體積大的；笨重的voltage['v?ultid?]n.電壓n.電波beam[bi?m]plasma['pl?zm?]n.等離子體recordable[ri'k??d?bl]adj.可記錄的sheet[?i?t][pin]n.紙張pinn.針n.帶ribbon['rib?n]dot-matrix[d?t-'meitriks]n.點矩陣ink-jet[i?k-d?et]adj.噴墨的droplet['dr?plit]n.小滴n.字符character['k?r?kt?]43Wordslaser['leiz?]n.激光particle['pɑ?tikl]n.顆粒n.色粉toner['t?un?]fuse[fju?z]v.融化headset['hedset]n.耳機(jī)stereo['ster???;'st??r???]n.立體聲encode[en'k?ud]v.編碼magneto-optical[m?g'ni?t?u-'?ptik?l]n.磁光circular['s??kjul?]adj.圓形的magnetically[m?g'netikli]adv.有磁力地insert[in's??t;'ins??t]v.插入enclose[in'kl?uz]v.裝入；附上shell[?el]n.殼reflective[ri'flektiv]adj.反射的；反映的44Wordsfilm[film]n.膠卷telemedicine['teli,medisin]n.遠(yuǎn)程醫(yī)療ceiling['si?li?]n.天花板auditorium[???di't?:ri?m]n.禮堂；觀眾席portable['p??t?b(?)l][ai'dentifai]adj.手提的；便攜的identifyv.識別kiosk['ki??sk;ki'?sk]n.涼亭；報攤barcode[bɑ?'k??d]n.條形碼representation[?reprizen'tei??n]n.變現(xiàn)；代表linear['lini?]adj.線型的45Wordsspacing['speisi?]n.間隔one-dimensionaltwo-dimensional[w?n-di'men??n?l]adj.一維的adj.二維的[tu?-di'men??n?l]rectangle['rek?t??gl]n.矩形hexagon['heks?g?n]n.六邊形geometric[d?i?u'metrik]adj.幾何圖形的lens[lenz]n.鏡頭46Phrases47WordsBooleanlogiclogicoperationcarryoutcontrolunitregistersetmainmemoryvolatilememorynonvolatilememoryexposeto布爾邏輯邏輯運算執(zhí)行控制單元寄存器組內(nèi)存易失存儲器非易失存儲器使暴露；使遭受48Wordselectricalchargebetrappedininsulatedgatecrystalwindowharddiskfloppydiskcompactdiskflatbedscannerstandforparisonto電荷被困在；蘊含在絕緣閘晶體窗口硬盤軟盤光盤平板掃描儀代表與……相比49Wordsflat-paneldisplayemissivedisplayputerprintheadbackandforthodiskdrivebesensitivetoattachtojectorconsistof平板顯示器發(fā)射型顯示器主機(jī)打印頭反復(fù)地；來回地把……插入磁盤驅(qū)動器對……敏感附屬；依附投影儀由……組成50Abbreviations51AbbreviationsALUROMSRAMDRAMPROMEPROM運算器(ArithmeticandLogicalUnit)只讀存儲器(ReadOnlyMemory)靜態(tài)隨機(jī)存儲器(StaticRandomAccessMemory)動態(tài)隨機(jī)存儲器(DynamicRandomAccessMemory)可編程只讀存儲器(ProgrammableReadOnlyMemory)可擦可編程只讀存儲器(ErasableandProgrammableReadOnlyMemory)EEPROM電可擦可編程只讀存儲器(ElectricallyErasableandProgrammableReadOnlyMemory)52AbbreviationsVDUCRTLEDLCDCD-ROMCD-RW視頻顯示單元(VisualDisplayUnit)陰極射線管(CathodeRayTube)發(fā)光二極管(Light-EmittingDiode)液晶顯示屏(LiquidCrystalDisplay)只讀光盤驅(qū)動器(CompactDiscRead-OnlyMemory)可復(fù)寫式光盤(RewritableCompactDisk)53Notes54Notes12Hence,hardwareisthebodyoftheBooleanlogic：布爾邏輯，得名于英computerandsoftwarethesoul.國數(shù)學(xué)家George在十九世紀(jì)中葉首次定義了邏輯的代數(shù)系統(tǒng)。在計算機(jī)中布爾邏輯定義若干布爾邏輯函數(shù)，有時候稱為操作符。每個邏輯函數(shù)類似于一個現(xiàn)實世界的邏輯運算，可以用來定義各種邏輯的情況。NOT表示“非”，AND表示“與”，OR表示“或”，XOR表示“異或”。Boole。GeorgeBoole在英語語言中，為了使語言簡潔明了，重點突出或上下文緊密相連，可以省去某些句子成分而保持句意不變，這種語言現(xiàn)象稱之為省略。本句為并列復(fù)合句，后邊的分句省略與前邊分句相同的成分：Hence,hardwarethebodyofthecomputerandsoftware(is)thesoul(ofthecomputer).is55Notes3It'snoticeablethatthesequenceofoperationsthatthecontrolunitgoesthroughtoprocessaninstructionisinitselflikeashortcomputerprogram.本句中，it是形式主語，真正的主語是that引導(dǎo)的從句thesequenceofoperationsthatthecontrolunitgoesthroughtoprocessaninstructionisincomputerprogram。在該從句中，thesequenceofoperations是主語，islikeashortcomputerprogram是謂語，thattheinstruction是一個定語從句，修飾和限定theprocessaninstruction作目的狀語，修飾goesthrough。in”。itselflikeashortcontrolunitgoesthroughtoprocessansequenceofoperations，動詞不定式toitself的意思是“本身，實質(zhì)上譯文：注意：控制器處理指令的操作順序本身就像一個短程序。56Notes4557Notes6758Exercise59Exercise1Explainthefollowingabbreviations.LEDSRAM發(fā)光二極管0102靜態(tài)隨機(jī)存儲器(Light-EmittingDiode)(StaticRandomAccessMemory)ROMALU0304只讀存儲器運算器(ReadOnlyMemory)(ArithmeticandLogicalUnit)60Exercise1Explainthefollowingabbreviations.CRTVDU陰極射線管0506視頻顯示單元(CathodeRayTube)(VisualDisplayUnit)PROM0708LCD可編程只讀存儲器液晶顯示屏(ProgrammableReadOnly(LiquidCrystalDisplay)Memory)61Exercise2Fillineachblankwithasuitabletermoraphraseaccordingtoitsdefinition.______CPU:anelectroniccircuitrythatprovidesthecomputationalabilityand01controlofthecomputer_peripheral___________:devicesthatprovideinputoroutputtothecomputer02_______memory_____:computerchipsthatstoreinformationforquickretrievalbytheCPU0362Exercise2Fillineachblankwithasuitabletermoraphraseaccordingtoitsdefinition._____modem_____:adeviceconnectsacomputertoatelephonelineandallows04informationtobetransmittedtoorreceivedfromanothercomputer____________controlunit______:aunitofCPUthatdecodeseachinstructionandturnsitintoaseriesofcontrolsignals05______byte:asequenceof8bitsprocessedasasingleunitofinformation0663Exercise3Decidewhetherthefollowingstatementsaretrueorfalse.Asystemcomputersystemiscomposedofhardwareandsoftwaresystem.1T2ACPUistheheartoftheentirecomputersystem.T3ROMisvolatilewhileRAMisnonvolatile.F(RAMisvolatilememorybecausetheinformationwithincomputerispoweredoffwhereasROMisnonvolatile)thecomputerchipsiserasedassoonasthe64Exercise3Decidewhetherthefollowingstatementsaretrueorfalse.Storagehardwarediskpermanently.suchasafloppydiskandahardcanstoreinformationandprograms4T5Ofalltypesofcurrentprinters,laserprintersproducethehighestquality.6TMicrophonesanddigitalcamerasareoutputdevices.F(Microphonesanddigitalcamerasareinputdevices)65Exercise4TranslatethefollowingtermsorphrasesfromEnglishintoChineseandviceversa.registerset可復(fù)寫式光盤寄存器組hostcomputerCD-RW邏輯運算主機(jī)logicoperationbinary條形碼二進(jìn)制的barcodearithmetic外部設(shè)備算法peripheraldevicecompactdisk易失存儲器光盤volatilememory66Exercise5TranslatethefollowingpassageintoChinese.Acomputer'smemorycanbeviewedasalistofcellsintomodernwhichcomputers,eachmemorycellissetuptostorebinarynumbersingroupsofeightbits,calledabyte.Acomputercanstoreanykindofinformationrepresentedineventrillionsofbytesofmemory.numberscanbeplacedorread.Inalmostallinmemoryaslongasitcanbesomehownumericalform.Moderncomputershavebillionsor67Exercise計算機(jī)的內(nèi)存可被視為一系列的單元，可以在單元中存取數(shù)字。在幾乎所有現(xiàn)代計算機(jī)中，每個內(nèi)存單元設(shè)置為存儲8位一組（稱作字節(jié)）的二進(jìn)制數(shù)。只要信息能夠以數(shù)字形式表示，計算機(jī)就可以在內(nèi)存中存儲任何類型的信息?，F(xiàn)代計算機(jī)有十億甚至萬億字節(jié)的內(nèi)存。68ReadingMaterial69ReadingMaterialSystemBusesAbusisacommunicationpathwayconn