计算机英语-hardware 7页

hardwareHardwareofamodernPersonalComputer.1.Monitor2.Motherboard3.CPU4.RAM5.Expansioncards6.Powersupply7.Opticaldiscdrive8.Harddiskdrive9.Keyboard10.MouseApersonalcomputerismadeupofmultiplephysicalcomponentsofcomputerhardware,uponwhichcanbeinstalledasystemsoftwarecalledoperatingsystemandamultitudeofsoftwareapplicationstoperformtheoperator'sdesiredfunctions.ThoughaPCcomesinmanydifferentforms,atypicalpersonalcomputerconsistsofacaseorchassisinatowershape(desktop),containingcomponentssuchasamotherboard.Contents\n[hide]·1Motherboard·2Powersupply·3Removablemediadevices·4Secondarystorage·5Soundcard·6Inputandoutputperipheralso6.1Inputo6.2Output·7SeealsoMotherboardMainarticle:MotherboardThemotherboardisthemaincomponentinsidethecase.ItisalargerectangularboardwithintegratedcircuitrythatconnectstherestofthepartsofthecomputerincludingtheCPU,theRAM,thediskdrives(CD,DVD,harddisk,oranyothers)aswellasanyperipheralsconnectedviatheportsortheexpansionslots.Componentsdirectlyattachedtothemotherboardinclude:·Thecentralprocessingunit(CPU)performsmostofthecalculationswhichenableacomputertofunction,andissometimesreferredtoasthe"brain"ofthecomputer.Itisusuallycooledbyaheatsinkandfan.·ThechipsetmediatescommunicationbetweentheCPUandtheothercomponentsofthesystem,includingmainmemory.·RAM(RandomAccessMemory)storesresidentpartofthecurrentrunningOS(OScoreandsoon)andallrunningprocesses(applicationsparts,usingCPUorinput/output(I/O)channelsorwaitingforCPUorI/Ochannels).·TheBIOSincludesbootfirmwareandpowermanagement.TheBasicInputOutputSystemtasksarehandledbyoperatingsystemdrivers.·InternalBusesconnecttheCPUtovariousinternalcomponentsandtoexpansioncardsforgraphicsandsound.oCurrent§Thenorthbridgememorycontroller,forRAMandPCIExpress\n§PCIExpress,forexpansioncardssuchasgraphicsandphysicsprocessors,andhigh-endnetworkinterfaces§PCI,forotherexpansioncards§SATA,fordiskdrives§ATAoObsolete§AGP(supersededbyPCIExpress)§VLBVESALocalBus(supersededbyAGP)§ISA(expansioncardslotformatobsoleteinPCs,butstillusedinindustrialcomputers)·ExternalBusControllerssupportportsforexternalperipherals.TheseportsmaybecontrolleddirectlybythesouthbridgeI/OcontrollerorbasedonexpansioncardsattachedtothemotherboardthroughthePCIbus.oUSBoFireWireoeSATAoSCSIPowersupplyMainarticle:Powersupplyunit(computer)Insideacustom-builtcomputer:thepowersupplyatthebottomhasitsowncoolingfan.Apowersupplyunit(PSU)convertsalternatingcurrent(AC)electricpowertolow-voltageDCpowerfortheinternalcomponentsofthecomputer.Somepowersupplieshaveaswitchtochangebetween230Vand115V.Othermodelshaveautomaticsensorsthatswitchinputvoltageautomatically,orareabletoacceptanyvoltagebetweenthoselimits.Powersupplyunitsusedincomputersarenearlyalwaysswitchmodepowersupplies(SMPS).TheSMPS\nprovidesregulateddirectcurrentpowerattheseveralvoltagesrequiredbythemotherboardandaccessoriessuchasdiskdrivesandcoolingfans.[edit]RemovablemediadevicesMainarticle:Computerstorage·CD(compactdisc)-themostcommontypeofremovablemedia,suitableformusicanddata.oCD-ROMDrive-adeviceusedforreadingdatafromaCD.oCDWriter-adeviceusedforbothreadingandwritingdatatoandfromaCD.·DVD(digitalversatiledisc)-apopulartypeofremovablemediathatisthesamedimensionsasaCDbutstoresupto12timesasmuchinformation.Itisthemostcommonwayoftransferringdigitalvideo,andispopularfordatastorage.oDVD-ROMDrive-adeviceusedforreadingdatafromaDVD.oDVDWriter-adeviceusedforbothreadingandwritingdatatoandfromaDVD.oDVD-RAMDrive-adeviceusedforrapidwritingandreadingofdatafromaspecialtypeofDVD.·Blu-rayDisc-ahigh-densityopticaldiscformatfordataandhigh-definitionvideo.Canstore70timesasmuchinformationasaCD.oBD-ROMDrive-adeviceusedforreadingdatafromaBlu-raydisc.oBDWriter-adeviceusedforbothreadingandwritingdatatoandfromaBlu-raydisc.·HDDVD-adiscontinuedcompetitortotheBlu-rayformat.·Floppydisk-anoutdatedstoragedeviceconsistingofathindiskofaflexiblemagneticstoragemedium.UsedtodaymainlyforloadingRAIDdrivers.·IomegaZipdrive-anoutdatedmedium-capacityremovablediskstoragesystem,firstintroducedbyIomegain1994.·USBflashdrive-aflashmemorydatastoragedeviceintegratedwithaUSBinterface,typicallysmall,lightweight,removable,andrewritable.Capacitiesvary,fromhundredsofmegabytes(inthesameballparkasCDs)totensofgigabytes(surpassing,atgreatexpense,Blu-raydiscs).·Tapedrive-adevicethatreadsandwritesdataonamagnetictape,usedforlongtermstorageandbackups.Secondarystorage\nHardwarethatkeepsdatainsidethecomputerforlateruseandremainspersistentevenwhenthecomputerhasnopower.·Harddisk-formedium-termstorageofdata.·Solid-statedrive-adevicesimilartoharddisk,butcontainingnomovingpartsandstoresdatainadigitalformat.·RAIDarraycontroller-adevicetomanageseveralinternalorexternalharddisksandoptionallysomeperipheralsinordertoachieveperformanceorreliabilityimprovementinwhatiscalledaRAIDarray.SoundcardMainarticle:SoundcardEnablesthecomputertooutputsoundtoaudiodevices,aswellasacceptinputfromamicrophone.Mostmoderncomputershavesoundcardsbuilt-intothemotherboard,thoughitiscommonforausertoinstallaseparatesoundcardasanupgrade.Mostsoundcards,eitherbuilt-inoradded,havesurroundsoundcapabilities.InputandoutputperipheralsMainarticle:PeripheralInputandoutputdevicesaretypicallyhousedexternallytothemaincomputerchassis.Thefollowingareeitherstandardorverycommontomanycomputersystems.WheelMouseInput\nMainarticle:Inputdevice·TextinputdevicesoKeyboard-adevicetoinputtextandcharactersbydepressingbuttons(referredtoaskeysorbuttons).·PointingdevicesoMouse-apointingdevicethatdetectstwodimensionalmotionrelativetoitssupportingsurface.§OpticalMouse-useslighttodeterminemousemotion.oTrackball-apointingdeviceconsistingofanexposedprotrudingballhousedinasocketthatdetectsrotationabouttwoaxes.oTouchscreen-sensestheuserpressingdirectlyonthedisplay·GamingdevicesoJoystick-acontroldevicethatconsistsofahandheldstickthatpivotsaroundoneend,todetectanglesintwoorthreedimensionsandreportsitsangleordirectiontothedeviceitiscontrolling.oGamepad-ahandheldgamecontrollerthatreliesonthedigits(especiallythumbs)toprovideinput.oGamecontroller-aspecifictypeofcontrollerspecializedforcertaingamingpurposes.·Image,VideoinputdevicesoImagescanner-adevicethatprovidesinputbyanalyzingimages,printedtext,handwriting,oranobject.oWebcam-avideocamerausedtoprovidevisualinputthatcanbeeasilytransferredovertheinternet.·AudioinputdevicesoMicrophone-anacousticsensorthatprovidesinputbyconvertingsoundintoelectricalsignals.OutputMainarticle:Outputdevice·Printer-adevicethatproducesapermanenthuman-readabletextofgraphicdocument.·Speakers-typicallyapairofdevices(2channels)whichconvertelectricalsignalsintoaudio.oHeadphones-forasingleuserhearingtheaudio.·Monitor-anelectronicvisualdisplaywithtextualandgraphicalinformationfromthecomputer.\noCRT-(CathodeRayTube)displayoLCD-(LiquidCrystalDisplay)asof2010,itistheprimaryvisualdisplayforpersonalcomputers.oLED-(light-emittingdiode)displayoOLED-OrganicLight-EmittingDiode