計(jì)算機(jī)硬件是計(jì)算機(jī)運(yùn)行所需要的設(shè)備-由可進(jìn)行物理處理的元件組成

ComputerEnglishIUnitTwoComputerArchitecture1SectionAIntroductionInputHardwareOutputHardwareStorageHardwareHardwareConnections2I.IntroductionComputerhardwareistheequipmentinvolvedinthefunctionofacomputerandconsistsofthecomponentsthatcanbephysicallyhandled.Thefunctionofthesecomponentsistypicallydividedintothreemaincategories:input,output,andstorage.計(jì)算機(jī)硬件是計(jì)算機(jī)運(yùn)行所須要的設(shè)備，由可進(jìn)行物理處理的元件組成。這些元件的功能一般分為3個(gè)主要類(lèi)別：輸入、輸出和存儲(chǔ)。3I.IntroductionComponentsinthesecategoriesconnecttomicroprocessors,specifically,thecomputer’scentralprocessingunit(CPU),theelectroniccircuitrythatprovidesthecomputationalabilityandcontrolofthecomputer,viawiresorcircuitrycalledabus.這些類(lèi)別的元件與微處理器相連接，特殊是與計(jì)算機(jī)的中心處理器相連接，而后者是通過(guò)被稱(chēng)之為總線(xiàn)的線(xiàn)路或電路來(lái)供應(yīng)計(jì)算實(shí)力和對(duì)計(jì)算機(jī)進(jìn)行限制的電子電路。4I.IntroductionSoftware,ontheotherhand,isthesetofinstructionsacomputerusestomanipulatedata,suchasaword-processingprogramoravideogame.Theseprogramsareusuallystoredandtransferredviathecomputer’shardwaretoandfromtheCPU.另一方面，軟件是計(jì)算機(jī)用來(lái)處理數(shù)據(jù)的一套指令，如字處理程序或者視頻游戲。這些程序通常被存儲(chǔ)起來(lái)，并由計(jì)算機(jī)硬件調(diào)入和調(diào)出中心處理器。5I.IntroductionSoftwarealsogovernshowthehardwareisutilized;forexample,howinformationisretrievedfromastoragedevice.TheinteractionbetweentheinputandoutputhardwareiscontrolledbysoftwarecalledtheBasicInputOutputSystem(BIOS)software.軟件也限制著硬件如何運(yùn)用；例如，如何從存儲(chǔ)設(shè)備中檢索信息。輸入與輸出硬件的交互作用是由基本輸入輸出系統(tǒng)（BIOS）軟件限制的。6I.IntroductionAlthoughmicroprocessorsarestilltechnicallyconsideredtobehardware,portionsoftheirfunctionarealsoassociatedwithcomputersoftware.Sincemicroprocessorshavebothhardwareandsoftwareaspectstheyarethereforeoftenreferredtoasfirmware.盡管微處理器在技術(shù)上仍被認(rèn)為是硬件，其部分功能也與計(jì)算機(jī)軟件有關(guān)系。既然微處理器同時(shí)具有硬件與軟件方面的特征，它們因此常常被稱(chēng)作固件。7II.InputHardwareInputhardwareconsistsofexternaldevices——thatis,componentsoutsideofthecomputer’sCPU——thatprovideinformationandinstructionstothecomputer.Alightpenisastyluswithalightsensitivetipthatisusedtodrawdirectlyonacomputer’svideoscreenortoselectinformationonthescreenbypressingaclipinthelightpenorbypressingthelightpenagainstthesurfaceofthescreen.Thepencontainslightsensorsthatidentifywhichportionofthescreenitispassedover.輸入硬件由給計(jì)算機(jī)供應(yīng)信息和指令的外部設(shè)備——亦即計(jì)算機(jī)中心處理器以外的元件——組成。光筆是具有光敏端頭的輸入筆，用來(lái)在計(jì)算機(jī)屏幕上干脆寫(xiě)畫(huà)，或者通過(guò)按光筆上的夾子或用光筆接觸屏幕來(lái)在屏幕上選擇信息。這種筆含有光傳感器，能夠識(shí)別屏幕上筆經(jīng)過(guò)的部分。8II.InputHardwareAmouseisapointingdevicedesignedtobegrippedbyonehand.Ithasadetectiondevice(usuallyaball)onthebottomthatenablestheusertocontrolthemotionofanon-screenpointer,orcursor,bymovingthemouseonaflatsurface.Asthedevicemovesacrossthesurface,thecursormovesacrossthescreen.Toselectitemsorchoosecommandsonthescreen,theuserpressesabuttononthemouse.鼠標(biāo)是為一只手抓握而設(shè)計(jì)的指示設(shè)備。它在底部有一個(gè)檢測(cè)裝置（通常是一個(gè)圓球），運(yùn)用戶(hù)通過(guò)在一個(gè)平面上移動(dòng)鼠標(biāo)能夠限制屏幕上指針或光標(biāo)的運(yùn)動(dòng)。當(dāng)鼠標(biāo)滑過(guò)平面的時(shí)候，光標(biāo)隨著在屏幕上移動(dòng)。要在屏幕上選擇項(xiàng)目或吩咐，用戶(hù)就點(diǎn)擊鼠標(biāo)上的按鈕。9II.InputHardwareAjoystickisapointingdevicecomposedofaleverthatmovesinmultipledirectionstonavigateacursororothergraphicalobjectonacomputerscreen.Akeyboardisatypewriter-likedevicethatallowstheusertotypeintextandcommandstothecomputer.Somekeyboardshavespecialfunctionkeysorintegratedpointingdevices,suchasatrackballortouch-sensitiveregionsthatlettheuser’sfingermotionsmoveanon-screencursor.操縱桿是由一根桿子組成的指示設(shè)備，該桿以向多個(gè)方向移動(dòng)來(lái)操縱計(jì)算機(jī)屏幕上的光標(biāo)或者其他圖形對(duì)象。鍵盤(pán)是一個(gè)像打字機(jī)的設(shè)備，它運(yùn)用戶(hù)得以向計(jì)算機(jī)鍵入文本和吩咐。有些鍵盤(pán)有特殊功能鍵或集成的指示設(shè)備，如軌跡球或者可以讓用戶(hù)通過(guò)手指的移動(dòng)來(lái)移動(dòng)屏幕上光標(biāo)的觸敏區(qū)。10II.InputHardware

Anopticalscanneruseslight-sensingequipmenttoconvertimagessuchasapictureortextintoelectronicsignalsthatcanbemanipulatedbyacomputer.Forexample,aphotographcanbescannedintoacomputerandthenincludedinatextdocumentcreatedonthatcomputer.Thetwomostcommonscannertypesaretheflatbedscanner,whichissimilartoanofficephotocopier,andthehand-heldscanner,whichispassedmanuallyacrosstheimagetobeprocessed.光掃描儀利用光感應(yīng)設(shè)備將圖片或文本等形式的圖像轉(zhuǎn)換成計(jì)算機(jī)能夠處理的電子信號(hào)。例如，一張照片能夠被掃入一臺(tái)計(jì)算機(jī)，然后包括在該計(jì)算機(jī)建立的文本文件中。最常見(jiàn)的兩種掃描儀類(lèi)型是平板式掃描儀和手持式掃描儀，前者類(lèi)似一臺(tái)辦公復(fù)印機(jī)，后者用手動(dòng)的方式從要處理的圖像上掃過(guò)。11II.InputHardwareAmicrophoneisadeviceforconvertingsoundintosignalsthatcanthenbestored,manipulated,andplayedbackbythecomputer.Avoicerecognition

moduleisadevicethatconvertsspokenwordsintoinformationthatthecomputercanrecognizeandprocess.

麥克風(fēng)是將聲音轉(zhuǎn)換成可被計(jì)算機(jī)存儲(chǔ)、處理和回放的信號(hào)的設(shè)備。語(yǔ)音識(shí)別模塊是將說(shuō)的話(huà)轉(zhuǎn)換成計(jì)算機(jī)能夠識(shí)別和處理的信號(hào)的設(shè)備。

12II.InputHardwareAmodem,whichstandsformodulator-demodulator,isadevicethatconnectsacomputertoatelephonelineandallowsinformationtobetransmittedtoorreceivedfromanothercomputer.Eachcomputerthatsendsorreceivesinformationmustbeconnectedtoamodem.調(diào)制解調(diào)器代表調(diào)制器―解調(diào)器，是將計(jì)算機(jī)與電話(huà)線(xiàn)連接、允許信息傳給或接自另一臺(tái)計(jì)算機(jī)的設(shè)備。每臺(tái)發(fā)送或接收信息的計(jì)算機(jī)都必需與調(diào)制解調(diào)器相連接。13II.InputHardwareTheinformationsentfromonecomputerisconvertedbythemodemintoanaudiosignal,whichisthentransmittedbytelephonelinestothereceivingmodem,whichconvertsthesignalintoinformationthatthereceivingcomputercanunderstand.計(jì)算機(jī)發(fā)送的信息由調(diào)制解調(diào)器轉(zhuǎn)換成音頻信號(hào)，然后通過(guò)電話(huà)線(xiàn)傳送到接收調(diào)制解調(diào)器上，由其將信號(hào)轉(zhuǎn)換成接收計(jì)算機(jī)能夠理解的信息。14III.OutputHardwareOutputhardwareconsistsofexternaldevicesthattransferinformationfromthecomputer’sCPUtothecomputeruser.Avideodisplay,orscreen,convertsinformationgeneratedbythecomputerintovisualinformation.Displayscommonlytakeoneoftwoforms:avideoscreenwithacathoderaytube(CRT)oravideoscreenwithaliquidcrystaldisplay(LCD).輸出硬件由將信息從計(jì)算機(jī)中心處理器傳給計(jì)算機(jī)用戶(hù)的外部設(shè)備構(gòu)成。視頻顯示器或屏幕將計(jì)算機(jī)生成的信息轉(zhuǎn)換成可視信息。顯示器一般有兩種形式：陰極射線(xiàn)管視頻屏幕和液晶顯示視頻屏幕。15III.OutputHardwareACRT-basedscreen,ormonitor,lookssimilartoatelevisionset.InformationfromtheCPUisdisplayedusingabeamofelectronsthatscansaphosphorescentsurfacethatemitslightandcreatesimages.AnLCD-basedscreendisplaysvisualinformationonaflatterandsmallerscreenthanaCRT-basedvideomonitor.LCDsarefrequentlyusedinlaptopcomputers.基于陰極射線(xiàn)管的屏幕或監(jiān)視器看起來(lái)就像一臺(tái)電視機(jī)。從中心處理器輸出的信息，運(yùn)用電子束顯示出來(lái)，其過(guò)程是電子束掃描熒光屏，而熒光屏則發(fā)出光并產(chǎn)生圖像。基于液晶顯示器的屏幕將可視信息顯示在比基于陰極射線(xiàn)管的視頻監(jiān)視器更平、更小的屏幕上。液晶顯示器常常用于膝上型計(jì)算機(jī)。16III.OutputHardwarePrinterstaketextandimagefromacomputerandprintthemonpaper.Dot-matrixprintersusetinywirestoimpactuponaninkedribbontoformcharacters.Laserprintersemploybeamsoflighttodrawimagesonadrumthatthenpicksupfineblackparticlescalledtoner.Thetonerisfusedtoapagetoproduceanimage.Inkjetprintersfiredropletsofinkontoapagetoformcharactersandpictures.打印機(jī)將計(jì)算機(jī)輸出的文本和圖像打印在紙上。點(diǎn)陣打印機(jī)運(yùn)用細(xì)小的金屬絲打擊色帶，從而形成字符。激光打印機(jī)運(yùn)用光束在磁鼓上畫(huà)圖像，然后由磁鼓吸起被稱(chēng)之為色粉的微小黑粒。色粉熔凝到紙上，形成圖像。噴墨打印機(jī)將小墨滴噴射到紙上，形成字符和圖像。17IV.StorageHardwareStoragehardwareprovidespermanentstorageofinformationandprogramsforretrievalbythecomputer.Thetwomaintypesofstoragedevicesarediskdrivesandmemory.Thereareseveraltypesofdiskdrives:hard,floppy,magneto-optical,andcompact.Harddiskdrivesstoreinformationinmagneticparticlesembeddedinadisk.Usuallyapermanentpartofthecomputer,harddiskdrivescanstorelargeamountsofinformationandretrievethatinformationveryquickly.

存儲(chǔ)硬件為計(jì)算機(jī)檢索供應(yīng)信息和程序的永久性存儲(chǔ)。兩種主要的存儲(chǔ)設(shè)備是磁盤(pán)驅(qū)動(dòng)器和存儲(chǔ)器。磁盤(pán)驅(qū)動(dòng)器有幾種類(lèi)型：硬盤(pán)、軟盤(pán)、磁光盤(pán)和光盤(pán)。硬盤(pán)驅(qū)動(dòng)器將信息存儲(chǔ)在盤(pán)中嵌入的磁性顆粒中。硬盤(pán)驅(qū)動(dòng)器通常是計(jì)算機(jī)的固定部分，能存儲(chǔ)大量的信息并對(duì)其進(jìn)行快速的檢索。18IV.StorageHardwareFloppydiskdrivesalsostoreinformationinmagneticparticlesembeddedinremovabledisksthatmaybefloppyorrigid.Floppydisksstorelessinformationthanaharddiskdriveandretrievetheinformationatamuchslowerrate.Magneto-opticaldiscdrivesstoreinformationonremovablediscsthataresensitivetobothlaserlightandmagneticfields.Theycantypicallystoreasmuchinformationasharddisksbuthaveslightlyslowerretrievalspeeds.軟盤(pán)驅(qū)動(dòng)器也將信息存儲(chǔ)在磁性顆粒中，但這些顆粒是嵌入在可移動(dòng)的盤(pán)中，而這些盤(pán)既可能是軟的也可能是硬的。軟盤(pán)比硬盤(pán)存儲(chǔ)的信息少，檢索該信息的速度也慢得多。磁光盤(pán)驅(qū)動(dòng)器將信息存儲(chǔ)在對(duì)激光和磁場(chǎng)都敏感的可移動(dòng)盤(pán)上。它們可存儲(chǔ)的信息通常與硬盤(pán)一樣多，但檢索速度略微慢一點(diǎn)。19IV.StorageHardware

Compactdiscdrives(CD-ROM)storeinformationonpitsburnedintothesurfaceofadiscofreflectivematerial.TheinformationstoredonCD-ROMscannotbeerased(erase)oroverwritten(overwrite)withnewinformation.Theycanstoreaboutasmuchinformationasaharddrivebuthaveaslowerrateofinformationretrieval.由反射材料制成的光盤(pán)，其表面燒蝕出凹陷區(qū)。光驅(qū)（CD-ROM）就是將信息存儲(chǔ)于此。存儲(chǔ)在光盤(pán)上的信息不能擦除或用新信息改寫(xiě)。它們能夠存儲(chǔ)和硬盤(pán)差不多的信息量，但信息檢索速度比其慢。

20IV.StorageHardwareMemoryreferstothecomputerchipsthatstoreinformationforquickretrievalbytheCPU.Randomaccessmemory(RAM)isusedtostoretheinformationandinstructionsthatoperatethecomputer’sprograms.存儲(chǔ)器是指存儲(chǔ)信息供中心處理器快速檢索的計(jì)算機(jī)芯片。隨機(jī)訪(fǎng)問(wèn)存儲(chǔ)器（RAM）用來(lái)存儲(chǔ)操作計(jì)算機(jī)程序的信息和指令。21IV.StorageHardware

Typically,programsaretransferredfromstorageonadiskdrivetoRAM.RAMisalsoknownasvolatilememorybecausetheinformationwithinthecomputerchipsislostwhenpowertothecomputeristurnedoff.通常，程序由磁盤(pán)驅(qū)動(dòng)器的存儲(chǔ)區(qū)調(diào)到隨機(jī)訪(fǎng)問(wèn)存儲(chǔ)器中。隨機(jī)訪(fǎng)問(wèn)存儲(chǔ)器也稱(chēng)作易失性存儲(chǔ)器，因?yàn)楫?dāng)計(jì)算機(jī)的電源關(guān)閉時(shí)，計(jì)算機(jī)芯片中的信息隨著丟失。22IV.StorageHardwareRead-onlymemory(ROM)containscriticalinformationandsoftwarethatmustbepermanentlyavailableforcomputeroperation,suchastheoperatingsystemthatdirectsthecomputer’sactionsfromstartuptoshutdown.ROMiscallednonvolatilememorybecausethememorychipsdonotlosetheirinformationwhenpowertothecomputeristurnedoff.只讀存儲(chǔ)器（ROM）包含必需永久可供計(jì)算機(jī)操作運(yùn)用的關(guān)鍵信息和軟件，如從開(kāi)機(jī)到關(guān)機(jī)始終指揮計(jì)算機(jī)的運(yùn)行的操作系統(tǒng)。只讀存儲(chǔ)器稱(chēng)之為非易失性存儲(chǔ)器，因?yàn)楫?dāng)計(jì)算機(jī)的電源關(guān)閉時(shí)，存儲(chǔ)芯片中的信息不會(huì)丟失。23IV.StorageHardwareSomedevicesservemorethanonepurpose.Forexample,floppydisksmayalsobeusedasinputdevicesiftheycontaininformationtobeusedandprocessedbythecomputeruser.Inaddition,theycanbeusedasoutputdevicesiftheuserwantstostoretheresultsofcomputationsonthem.有些設(shè)備有不止一種用途。例如，軟盤(pán)也可用作輸入設(shè)備，假如它們含有計(jì)算機(jī)用戶(hù)要運(yùn)用和處理的信息的話(huà)。此外，它們也可用作輸出設(shè)備，假如用戶(hù)想將計(jì)算結(jié)果存儲(chǔ)在它們上面的話(huà)。24V.HardwareConnectionsTofunction,hardwarerequiresphysicalconnectionsthatallowcomponentstocommunicateandinteract.Abusprovidesacommoninterconnectedsystemcomposedofagroupofwiresorcircuitrythatcoordinates(coordinate)andmovesinformationbetweentheinternalpartsofacomputer.要想運(yùn)轉(zhuǎn)，硬件須要物理連接，使元件之間能夠溝通和相互作用。總線(xiàn)供應(yīng)了一種常見(jiàn)的互連系統(tǒng)，它由一組導(dǎo)線(xiàn)或電路組成，在計(jì)算機(jī)的內(nèi)部組成部分之間協(xié)調(diào)和移動(dòng)信息。25V.HardwareConnectionsAcomputerbusconsistsoftwochannels(channel):onethattheCPUusestolocatedata,calledtheaddressbus,andanothertosendthedatatothataddress,calledthedatabus.Abusischaracterized(characterize)bytwofeatures(feature):howmuchinformationitcanmanipulateatonetime,calledthebuswidth,andhowquicklyitcantransferthesedata.計(jì)算機(jī)總線(xiàn)由兩條通道組成：一條由中心處理器用來(lái)給數(shù)據(jù)定位，叫做地址總線(xiàn)；另一條用來(lái)將該數(shù)據(jù)送往那個(gè)地址，叫做數(shù)據(jù)總線(xiàn)。總線(xiàn)可用兩個(gè)特征來(lái)描述：一次可處理的信息量，稱(chēng)為總線(xiàn)寬度，和傳送這些數(shù)據(jù)的速度。26V.HardwareConnectionsAserialconnectionisawireorsetofwiresusedtotransferinformationfromtheCPUtoanexternaldevicesuchasamouse,keyboard,modem,scanner,andsometypesofprinters.Thistypeofconnectiontransfersonlyonepieceofdataatatime,andisthereforeslow.Theadvantagetousingaserialconnectionisthatitprovideseffectiveconnectionsoverlongdistances.串行連接是一根或一組導(dǎo)線(xiàn)，用于將信息從中心處理器傳送到外部設(shè)備，如鼠標(biāo)、鍵盤(pán)、調(diào)制解調(diào)器、掃描儀和一些類(lèi)型的打印機(jī)。這種連接一次只能傳送一段數(shù)據(jù)，因此很慢。運(yùn)用串行連接的好處在于它能供應(yīng)遠(yuǎn)距離的有效連接。27V.HardwareConnectionsAparallelconnectionusesmultiplesetsofwirestotransferblocks(block)ofinformationsimultaneously.Mostscannersandprintersusethistypeofconnection.Aparallelconnectionismuchfasterthanaserialconnection,butitislimitedtodistancesoflessthan3m(10ft)betweentheCPUandtheexternaldevice.并行連接運(yùn)用多組導(dǎo)線(xiàn)來(lái)同時(shí)傳送數(shù)個(gè)信息塊。大多數(shù)掃描儀和打印機(jī)運(yùn)用這種連接方式。并行連接比串行連接快得多，但是它在中心處理器和外部設(shè)備之間的傳輸距離僅限于不到3米（10英尺）。28ExerciseIII.

CD-ROMstandsforcompactdiskread-onlymemory.Unlikefloppyandharddisks,whichusemagneticchargestorepresent1sand0s,opticaldisksusereflectedlight.OnaCD-ROMdisk,1sand0sarerepresentedbyflatarea