教學目標教學內容Unit2HardwareSystemofComputer教學目標了解計算機的體系結構了解CPU的組成理解指令執行周期的過程了解主板的功能了解存儲器的分類了解常見的輸入、輸出設備了解擴展槽的相關知識教學內容Text1ComputerHardwareArchitectureText2CPUarchitecturesText3MotherboardText4StorageText5Input&OutputDevicesText6ExpansionCardsText1ComputerHardwareArchitectureMainContentsWordsandExpressionsExercisesAcomputersystemiscomprisedofthefivebuildingblocks,aswellasadditionalperipheralsupportdevices,whichaidindatamovementandprocessing.Thesebasicbuildingblocksareusedtoformthegeneralprocessing,control,storage,andinputandoutputunitsthatmakeupmoderncomputersystems.Devicestypicallyareorganizedinamannerthatsupportstheapplicationprocessingforwhichthecomputersystemisintended,forexample,ifmassiveamountsofdataneedtobestored,thenadditionalperipheralstoragedevicessuchasdisksortapeunitsarerequired,alongwiththeirrequiredcontrollersordatachannels.Text1ComputerHardwareArchitectureAcomputersystem'sarchitectureisconstructedusingbasicbuildingblocks,suchasCPUs,memories,disks,I/O,andotherdevicesasneeded.Text1ComputerHardwareArchitectureTobetterdescribethevariationswithinarchitectureswewilldiscusssomedetailsbriefly,forexample,thearithmeticlogicunit(ALU)andthecontrolunitaremergedtogetherintoacentralprocessingunitorCPU.TheCPUcontrolstheflowofinstructionsanddatainthecomputersystem.MemoriescanbebrokendownintohierarchiesbasedonnearnesstotheCPUandspeedofaccess-forexample,cachememoryissmall,extremelyfastmemoryusedforinstructionsanddataactivelyexecutingandbeingusedbytheCPUandusuallyresidesonthesameboardorchipastheCPU.Theprimarymemoryisslower,butitisalsocheaperandcontainsmorememorylocations.ItisusedtostoredataandinstructionsthatwillbeusedduringtheexecutionofapplicationspresentlyrunningontheCPU,forexample,ifyoubootupyourwordprocessingprogramonyourpersonalcomputer,theoperatingsystemwillattempttoplacetheentirewordprocessingprograminprimarymemory.Ifthereisinsufficientspace,theoperatingsystemwillpartitiontheprogramintosegmentsandpulltheminasneeded.Text1ComputerHardwareArchitectureTheportionoftheprogramthatcannotbestoredinmemoryismaintainedonasecondarystoragedevice,typicallyadiskdrive.Thisdevicehasamuchgreaterstoragecapacitythantheprimarymemory,typicallycostsmuchlessperunitofstorage,andhasdataaccesstimesthataremuchslowerthantheprimarymemory.AmorerecentexternalstoragedeviceistheCD-ROMdrive.Thisdevice,initsread-onlymode(ROM),allowsusersonlytoextractinformationfromthedrive.Inthemorerecentread/writevarietythedevicecanbeusedsomewhatlikethetraditionaltapedrive.Anadditionalsecondarystoragedeviceisthetapedriveunit.Atapedriveisasimplestoragedevicethatcanstoremassiveamountsofdataagain,atlesscostthanthediskunitsbutatareducedaccessspeed.Othercomponentsofacomputersystemareinputandoutputunits.Theseareusedtoextractdatafromthecomputerandprovidethesedatatoexternaldevicesortoinputdatafromtheexternaldevice.Theexternaldevicescouldbeend-userterminals,sensors,informationnetworkports,video,voice,orothercomputers.Text1ComputerHardwareArchitectureInthefollowingsectionswewillexamineeachofthecomponentsofacomputersysteminmoredetail,asweexaminehowthesedevicescanbeinterconnectedtosupportdataprocessingapplications.Text1ComputerHardwareArchitectureWordsandExpressionssystemsoftware系統軟件applicationsoftware應用軟件accomplish[?'k?mpli?;?'k?m-]vt.達到(目的)；完成(任務、使命、計劃、事業等)；實現(諾言、計劃等)：diagnosticroutines【計算機】診斷(例行)程序[亦作diagnosticsubroutine,diagnostictest]basicinput-outputsystem基本輸入輸出系統operatingsystem操作系統graphicaluserinterface(GUI)圖形用戶界面mechanism['mek?niz?m]n.機械,機構,結構機制，原理reenter[,ri:'ent?]vt.再進入；重返OLE(objectlinkingandembedding)functions對象連接與嵌入功能DDE(dynamicdataexchange)動態數據交換clipboard['klipb?:d]n.剪貼板WordsandExpressionssophisticated[s?'fistikeitid]adj.（系統、流程、技術等)極其復雜的，精密的，尖端的，發達的replacement[ri'pleism?nt]n.交換,更換,代替者21世紀大英漢詞典》

alternative[?:l't?:n?tiv]adj.1.兩者(或兩者以上)擇一的，二擇其一的，可從數個中任擇其一的；(兩種選擇中)非此即彼的2.供替代的；供選擇的3.(兩者)互斥的independently[indi'pend?ntli]adv.獨立地,自立地milestone['mailst?un]n.里程碑merge[m?:d?]vt.【計算機】合并pictorial[pik't?:ri?l]adj.1.圖片的；用圖片表示的；由圖片組成的；2.形象化的；生動的newsletters['nju:z,let?(r)]n.時事通訊,時事分析,時事傳報21世紀大英漢詞典》

AT&T美國電話電報公司(財富500強公司之一，總部所在地美國,主要經營電訊)portable['p?:t?bl]adj.【計算機】可移植的，不經修改便可在任何計算機上使用的multiprocessing[,m?lti'pr?usesi?;-'pr?-]n.【計算機】多重處理(使用兩個以上通往同一記憶系統的電腦處理機，能同時處理多項程序)，多道處理ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Systemsoftwareisaspecializedprogramsthatenablestheusertoaccomplishspecifictasks.（）2.Theoperatingsystemhelpsmanagecomputerresources.（）3.Windowsgetsitsnamebecauseofitsabilitytorunmultipleapplicationsatthesametime,eachinitsownwindow.（）4.WindowsalsohasDDE(dynamicdataexchange)andOLE(objectlinkingandembedding)functions.（）5.OLEdon’tallowtheapplicationreceivingthedatatodirectlyaccesstheapplicationthatcreatedthedata.（）6.Withmultiprocessing,thedemandsofthedatabasemanagementprogramdoaffecttheprintingofthedocument.（）7.WindowsNThasnetworkcapabilitiesandsecuritychecksbuiltintotheoperatingsystem.Thismakesnetworkinstallationanduserelativelyeasy.（）8.OS/2wasdevelopedonlybyMicrosoftCorporation.（）9.TheMacintoshSoftware,whichrunsonlyonMacintoshcomputers,offersahigh-qualitygraphicaluserinterfaceandisveryhardtouse.（）10.UnixwasoriginallydevelopedbyAT&Tforminicomputersandisverygoodformultitasking.ExercisesII.Fillintheblankswithproperwords.1.Softwarereferstocomputerprograms.__________aretheinstructionsthattellthecomputerhowtoprocessdataintotheformyouwant.2.Therearetwokindsofsoftware:systemsoftwareand__________software.3.__________softwareisacollectionofprogramsthatenablesapplicationsoftwaretorunonacomputersystem'shardwaredevices,itisbackgroundsoftwareandincludesprogramsthathelpthecomputermanageitsowninternalresources.4.__________softwareconsistsoffourkindsofprograms:bootstraploader,diagnosticroutines,basicinput-outputsystem,andoperatingsystem.5.Windowsoffers__________,presentstheuserwithgraphicimagesofcomputerfunctionsanddata.6.LikeWindows,WindowsNT,andOS//2,theMacintoshSystemenablesyoutodo__________Thatis,severalprogramscanrunatthesametime.7.Unixisbecomingalargerplayerinthemicrocomputerworld.Unixcanbeusedwithdifferenttypesofcomputersystems,thatis,itisaportableoperatingsystem.Itisusedwithmicrocomputers,minicomputers,__________,andsupercomputers.Text2CPUarchitecturesMainContentsWordsandExpressionsExercisesThecentralprocessingunit(CPU)isthebrainsofacomputersystem.TheCPUconsistsofthearithmeticlogicunit(ALU)andthecontrolunit,asindicatedpreviously.TheALUcancomeinavarietyofconfigurationsfromasinglesimpleunit,thatperformssimpleadds,subtracts,increments,decrements,load,andstore,uptoextremelycomplexunitsthatperformoperationssuchasmultiply,divide,exponentiation,sine,cosine,andsoon.TheprimaryoperationoftheALUistotakezeroormoreoperandsandperformthefunctioncalledforintheinstruction.InadditiontotheALU,theCPUconsistsofasetofregisterstostoreoperandsandintermediateresultsandtomaintaininformationusedbytheCPUtodeterminethestateofitscomputations.ThereareregistersforthestatusoftheALU'soperation,forkeepingcountoftheinstructiontobeperformednext,tokeepdataflowinginfrommemoryorouttomemory,tomaintaintheinstructionbeingexecuted,andforthelocationofoperandsbeingoperatedonbytheCPU.Text2CPUarchitecturesEachoftheseregistershasauniquefunctionwithintheCPU,andeachisnecessaryforvariousclassesofcomputerarchitectures.AtypicalminimalarchitectureforaCPUanditsregistersisshowninFig.2.1.ThisarchitectureconsistsofaprimarymemoryconnectedtotheCPUviabusesthatuseamemoryaddressregisterandmemorydataregistertoaddressalocationinmemoryandtransferthecontentsofthelocationfromthememoryintothememorydataregisterortotransferthecontentsofthememorydataregisterintomemory.ThereareregistersintheCPUforinstructions(theinstructionorIRregister),instructionoperands,andresultsofoperations;alocationcounter(whichcontainseitherthelocationinmemoryforinstructionsoroperands,dependingonthedecodingofinstructions);aprogramcounterorPC(whichmaintainsthelocationofthenextinstructiontoperform);andstatusregisters.MARMemoryArrayMDRCPURegistersPCIRText2CPUarchitecturesMARMemoryArrayMDRCPURegistersPCIRFig.2.1theCPUanditsAssociatedRegistersText2CPUarchitecturesTheCPUalsocontainsthecontrolunit.ThecontrolunitusesthestatusregistersandinstructionsintheinstructionregistertodeterminewhatfunctionstheCPUmustperform.Registers,ALU,anddatapathsthatmakeuptheCPU.ThebasicoperationoftheCPUfollowsasimpleloop(unlessinterruptsoccurthataltertheflowofexecution).Thisloopiscalledtheinstructionexecutioncycle(Fig.2.2).Therearesixbasicfunctionsperformedintheinstructionloop:instructionfetch,instructiondecode,operandeffectiveaddresscalculation,operandfetch,operationexecution,andnextaddresscalculation.Fig.2.2InstrumentationExecution

CycleInstructionFetchInstructionDecodeOperandAddressComputationNextInstructionAddressComputationInstructionExecutionOperandFetchInstructionfetchusestheprogramcounterregistertopointtothenextinstructionstoredinmemory.Theaddressisplacedinthememoryaddressregisterandtheinstructionisthengated(electronicallysignaledbytheCPUcontrolelementtotransferthedata)fromthedatamemoryintothememorydataregister.Theinstructionthenflowsintotheinstructionregisterunderthedirectionofthecontrolunit.Onceaninstructionisintheinstructionregister,thesecondcycleininstructionexecutioncanbeperformeddecode.Todecodetheinstructionthecontrolunitmustrecognizewhattypeofinstructionisbeingrequestedforexample,doestheinstructionrequireadditionaldatafrommemorytoperformitsintendedfunction,ordoestheinstructioninvolveonlyALUresidentregisters?Thethirdcyclewithininstructionexecutionistheoperandeffectiveaddresscalculation.Thisphaseofinstructionexecutionoperatesbyextractingoperandaddressinformationfromtheinstructionandthenperformingsomeformofcalculation(e.g.,baseplusoffset)withthisinformationtoformaphysicaladdressinmemory.Oncethetypeandnumberofoperandsaredetermined,theALUcanacquiretheoperandsandthensetuptoperformthedecodedinstruction.Oncewehaveaphysicaladdress,wecanfetchtheoperand(thefourthfunctionoftheinstructionexecutioncycle).Tofetchtheoperandtheeffectiveaddressisplacedinthememoryaddressregister,andthecontrolgatesthecontentspointedtobythememoryaddressregisterintothememorydataregister.TheextractedoperandisthengatedfromthememorydataregisterintoanALUregister.Ifanadditionaloperandisneeded,thetwocyclestepsforoperandfetchwouldberepeatedtogettheremainingoperand.WithallrequiredoperandsinALUregisterstheinstructionrequestedcannowbeperformed.TheinstructionexecutioniscontrolledbytheCPUcontrolunit.ThecontrolunitsignalstotheALUtoperformtheinstructionforexample,ifanaddisrequestedtheALUwouldaddtheAandBregistersandplacetheresultintheCregister.Aftertheinstructioniscompletedthelaststepintheinstructionexecutioncyclecanproceed.Thenextaddresscalculationusestheprogramcounterand/oranypertinentcomputationresulttodeterminewhereinthememorythenextinstructionistobefound.Thenormalmodeofaddresscalculationistoincrementthecontentsoftheprogramcounter.Withthenewaddresstheinstructioncyclebeginsoncemore.Thisexecutionsequencerepresentsthebasicfunctionsfoundinallcomputersystems.Variationsinthenumberofstepsarefoundbasedonthetypeandlengthoftheinstruction.WordsandExpressionsconfiguration[k?n,figju'rei??n]n.結構,布局,形態[計算機]配置perform[p?'f?:m]vt.執行；履行AdvancedDataDisplaySystem(adds)高級數據顯示系統subtract[s?b'tr?kt]vt.扣除，減少，減損：increment['inkrim?nt]n.增加(增加物,增量,余差)decrement['dekrim?nt]n.漸減,減少,減少量[計算機]遞減multiply['m?ltiplai]vt.【數學】乘，使相乘：divide[di'vaid]vt.【數學】除，用除法分成相等的幾份；除盡；把…作除數，以…相除：exponentiation['eksp?u,nen?i'ei??n]n.【數學】取冪sine[sain;'saini;'sinei]n.【幾何學】1)正弦2)(角的)正弦函數cosine[‘k?usain]n.【三角學】余弦WordsandExpressionsintermediate[,int?'mi:dj?t;-dieit]adj.中間的，居間的minimal['minim?l]adj.最小的；最少的；最低限度的statusregister狀態寄存器interrupt[,int?'r?pt]n.中斷v.打斷,妨礙,插嘴[計算機]中斷theinstructionexecutioncycle指令執行周期instructionloop閉合指令循環回路instructiondecode指令譯碼gatedamplifier選通放大器decode[,di:'k?ud]vt.譯(密碼文電等)，譯(碼)，解(碼)等：operand['?p?r?nd;,?p?'r?nd]n.【計算機】操作數acquire[?'kwai?]vt.(計算機、機器人等)捕捉，捕獲，截獲pertinent['p?:tin?nt]adj.恰當的；適當的；貼切的；中肯的；有關的ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.ThereareregistersintheCPUforinstructions,instructionoperands,andresultsofoperations;alocationcounter;aprogramcounterorPC(whichmaintainsthelocationofthenextinstructiontoperform);andstatusregisters.（）2.Onceaninstructionisintheinstructionregister,thesecondcycleininstructionexecutioncanbeperformedcode.（）3.Todecodetheinstructionthecontrolunitmustrecognizewhattypeofinstructionisbeingrequested.（）4.Thesecondcyclewithininstructionexecutionistheoperandeffectiveaddresscalculation.（）5.Oncethetypeandnumberofoperandsaredetermined,theALUcanacquiretheoperandsandthensetuptoperformthecodedinstruction.（）6.Variationsinthenumberofstepsarefoundbasedonthetypeandlengthoftheinstruction.ExercisesII.Fillintheblankswithproperwords.1.Thecentralprocessingunit(__________)isthebrainsofacomputersystem.2.TheCPUconsistsofthearithmeticlogicunit(ALU)andthe__________unit,asindicatedpreviously.3.The__________unitusesthestatusregistersandinstructionsintheinstructionregistertodeterminewhatfunctionstheCPUmustperform.4.Thereare__________basicfunctionsperformedintheinstructionloop:instructionfetch,instructiondecode,operandeffectiveaddresscalculation,operandfetch,operationexecution,andnextaddresscalculation.5.Instruction__________usestheprogramcounterregistertopointtothenextinstructionstoredinmemory.6.TheinstructionexecutioniscontrolledbytheCPU__________unit.Text3MotherboardMainContentsWordsandExpressionsExercisesAmotherboardisthecentralprintedcircuitboard(PCB)insomecomplexelectronicsystems,suchasmodernpersonalcomputers.Themotherboardissometimesalternativelyknownasthemainboard,systemboard,or,onApplecomputers,thelogicboard.Itisalsosometimescasuallyshortenedtomobo.Modernmotherboardsinclude,ataminimum:sockets(orslots)inwhichoneormoremicroprocessorsareinstalled.

slotsintowhichthesystem'smainmemoryisinstalled(typicallyintheformofDIMMmodulescontainingDRAMchips)achipsetwhichformsaninterfacebetweentheCPU'sfront-sidebus,mainmemory,andperipheralbuses

non-volatilememorychips(usuallyFlashROMinmodernmotherboards)containingthesystem'sfirmwareorBIOS

aclockgeneratorwhichproducesthesystemclocksignaltosynchronizethevariouscomponentsslotsforexpansioncards(theseinterfacetothesystemviathebusessupportedbythechipset)powerconnectorsflickers,whichreceiveelectricalpowerfromthecomputerpowersupplyanddistributeittotheCPU,chipset,mainmemory,andexpansioncards.MostmodernmotherboarddesignsuseaBIOS,storedinanEEPROM

chip

solderedtothemotherboard,tobootstrapthemotherboard.(SocketedBIOSchipsarewidelyused,also.)Bybootingthemotherboard,thememory,circuitry,andperipheralsaretestedandconfigured.ThisprocessisknownasacomputerPower-OnSelfTest(POST)andmayincludetestingsomeofthefollowingdevices:floppydrive

networkcontrollerCD-ROMdriveDVD-ROMdriveSCSIharddriveIDE,EIDE,orSATA

harddrive

ExternalUSBmemorystoragedeviceWordsandExpressionsmotherboard主板，母板PCB(printedcircuitboard)印刷電路板mainboard主板alternatively[?:lt?:n?tivli]adv.二者擇一地,非此即彼，如其不然；或，要不microprocessor

[maikr?upr?ses?]n.微處理器case機箱backplane

底板mainframe[‘mein,freim]n.【計算機】(電腦)主機;主機機樞;主機機架;中央處理機WordsandExpressionscentralprocessingunit【計算機】中央處理機,中央處理裝置[略作CPU,亦作centralprocessor]peripheral[p?'rif?r?l]adj.不重要的,外圍的n.【計算機】外圍設備；輔助設備(如打印機、掃描儀等)[亦作peripheric]ICs內部通信系統serial['si?ri?l]n.序列,串列adj.連續的,一連串的【計算機】串聯的，串行的，非并行的parallel['p?r?lel]adj.平行的adv.平行地n.平行線vt.與...平行【計算機】并行expansioncard擴展卡WordsandExpressionsMicronics邁科Molex莫萊克斯AMI美國米格特雷德公司DTK創宏Hauppauge哈帕克OrchidTechnology蘭花科技Elitegroup精英DFI友通schematic[ski'm?tik]adj.扼要的,圖解的n1.圖表，略圖，簡圖2.【電工學】電路圖,原理圖reverse-engineering逆向工程，反求工程WordsandExpressionscompatible[k?m'p?t?bl]a.能共處的,可并立的,適合[計算機]相兼容的upgrade[?p'greid]vt.提高(上升,濃集,加強)n.提高(上升,濃集,加強)archaically[ɑ:'keiikli]adv.已廢地,古老地,古代地embeddedsystems嵌入式系統daughterboard子板socket['s?kit]n.插座，管座，插口slot[sl?t]槽，縫stop-watch記秒表，秒表，停表desktopcomputer臺式計算機，臺式電腦mainmemory主存externalstorage外部存儲器WordsandExpressionsplug-in插件程序integrate['intigreit]v.整合,使...成整體a.真誠的chipset芯片集，晶元組bus母線，總線toanextent在一定程度上DIMM（Dual

In-line

Memory

Modules）雙重內嵌式內存模塊DRAM（Dynamic

Random

Access

Memory）動態隨機存儲器firmware['f?:m,w??]n.固化程序，固件；燒寫到一塊芯片上的程序命令集BIOS（Basic

Input/Output

System）基本輸入/輸出系統interface界面,接口heatsink吸熱設備，冷源，散熱片layout

['leiaut]n.布局，安排，設計facilitate[f?'siliteit]v.幫助,使...容易,促進architecture['ɑ:kitekt??]n.建筑學,建筑業【計算機】計算機構造，架構，體系結構budget

[‘b?d?it]n.預算vi.(for)編預算vt.規劃a.低廉的WordsandExpressionsfloppydiskdrive軟盤驅動器PATA（ParallelAdvanced

Technology

Attachment）并行高級技術附加裝置SATA（SerialAdvanced

Technology

Attachment）串行高級技術附加裝置RAID（Redundant

Array

of

Independent

Disks）獨立磁盤冗余陣列VGA（video

graphics

array）視頻圖像陣列S/PDIF（Sony/Phillips

Digital

Interface）索尼/飛利普數字接口USB（Universal

Serial

Bus）通用串行總線IrDA（infrared

ray）紅外線通信接口（可進行局域網存取和文件共享）ATX(Advanced

TechnologyExtend)擴展型先進技術PCI（Peripheral

Component

Interconnect）互連外圍設備PCI-E（Peripheral

Component

InterconnectExtend）擴展型互連外圍設備SLI（ScalableLinkInterface）雙顯卡NVIDIA輝達公司ATI冶天（計算機公司）WordsandExpressionsintensive[in'tensiv]a.集中的,強化的,精細的,深入的atleast1.最少;至少;起碼[亦作attheveryleast]2.無論如何northbridge北橋crash[kr??]n.猛撞,崩潰,破產,垮臺v.撞碎,迫降n.【計算機】(計算機)突然停止工作(死機)，失靈(狀態)passive['p?siv]a.被動的,消極的n.被動性sufficient[s?'fi??nt]a.足夠的,充分的reliability[ri,lai?'biliti]n.可靠性mulation仿真electrolytic[i,lektr?u'litik]a.電解的,由電解產生的evaporate[i'v?p?reit]v.蒸發,失去水分,消失instability[inst?'biliti]n.不安定,不穩定,基礎薄弱deliver[di‘liv?]v.遞送,表達,釋放,交付,接生WordsandExpressionsinadequate[in'?dikwit]a.不充分的,不適當的Macintosh蘋果機（計算機公司）Laptop便攜式電腦,膝上型電腦crossfire['kr?sfai?]n.交叉火力proprietary[pr?'prai?t?ri]a.專利的(所有的)n.所有權(所有人bootstrap['bu:tstr?p]引導指令(程序),輔助程序CD-ROM（CompactDisc,Read-OnlyMemory）只讀光盤DVD-ROM(DigitalVideoDisc,Read-OnlyMemory)只讀數字化視頻光盤SCSI

（Small

Computer

System

Interface）小型計算機系統接口IDE（Integrated

Drive

Electronics）電子集成驅動器EIDE（enhanced

Integrated

Drive

Electronics）增強型電子集成驅動器ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Motherboardisthemainprintedcircuitboardcontainingtheprimarycomponentsofacomputersystem.（）2.TheCPU,memoryandperipheralswerehousedonindividualprintedcircuitboardswhichpluggedintothebackplane.（）3.low-speedperipheralsincludekeyboard,mouse,floppydiskdrive,serialports,andparallelports.（）4.PopularpersonalcomputerssuchastheAppleIIandIBMPCdidn’tpermittedrapidreverse-engineeringandthird-partyreplacementmotherboards.（）5.Amotherboardspecificallyreferstoaprintedcircuitwiththecapabilitytoextenditsperformancewiththeadditionof"daughterboards".（）6.IBM-compatiblecomputersaccountforaround80%ofglobalPCsales.（）7.Inmoderncomputersitisincreasinglycommontointegratesomeofperipheralsintothemotherboarditself.（）8.Themicroprocessor'ssupportingchipsetprovidesonlythesupportinginterfacesbetweentheCPUandexternalcomponents.（）9.USB2.0controllersupportsupto12USBports（）10.CheapermachinesnowoftenhaveaseparatecardratherthantheirgraphicschipbuiltintothemotherboardExercisesII.Fillintheblankswithproperwords.1.Atypicaldesktopcomputerhasits__________,mainmemory,andotheressentialcomponentsonthemotherboard..2.Modernmotherboardsnearlyalwaysinclude__________andmountingpointsforfanstodissipateexcessheat.3.ACPUslotisanelectricalcomponentthatattachestoPCBandisdesignedto__________aCPU.4.Today,highly-integratedmotherboardsareespeciallypopularinsmallformfactorand__________computers.5.Commoditycomputershavebeenstandardizedtofitvarious__________sizes.6.Capacitorsofthemotherboardageatatemperature-dependentrate,astheirwaterbasedelectrolytesslowly__________.7.Laptopcomputersgenerallyusehighly__________integrated,miniaturized,andcustomizedmotherboards.Text4StorageMainContentsWordsandExpressionsExercisesThepurposeofstorageinacomputeristoholddataorinformationandgetthatdatatotheCPUasquicklyaspossible.Computersusedisksforstorage:harddisksthatarelocatedinsidethecomputer,andfloppyorcompactdisksthatareusedexternally.(1)memory(2)Floppydisks(3)Compactdisks(4)MagneticTape(1)memoryYourcomputerusestwotypesofmemory:primarymemoryharddisktimes.(2)FloppydisksFloppydisksarealsocalleddiskettes,flexibledisks,floppies,orsimplydisks.Whenyoulookatafloppydisk,you'llseeaplasticcasethatmeasures3.5by5inches.Thereisaverythinpieceofplasticinsidethatcase.Thisdiskismuchlikethetapeinsideavideooraudiocassette.Atoneendofitisasmallmetalcoverwitharectangularholeinit.Thatcovercanbemovedasidetoshowtheflexiblediskinside.Butnevertouchtheinnerdisk!Youcoulddamagethedatathatisstoredonit.Ononesideofthefloppydiskisaplaceforalabel.Ontheothersideisasilvercirclewithtwoholesinit.Theplasticdiskinsidethediskettecoverisflexible,notrigid.Theyareflat,circularpiecesofmylarplasticthatrotatewithinajacket.Dataandprogramsarestoredaselectromagneticchargesonametaloxidefilmcoatingthemylarplastic.Whenthediskisinsertedintothediskdrive,thedrivehooksintothoseholestospinthecircle.Thiscausesthediskinsidetospinatabout300rpm!Floppydisksarethesmallesttypeofstorage,holdingonly1.44MB.(3)CompactdisksOpticaldisksareusedforstoringgreatquantitiesofdata.Anopticaldiskcanhold650megabytesofdata—theequivalentofhundredsoffloppydisks.Moreover,anopticaldiskmakesanimmenseamountofinformationavailableonamicrocomputer.Inoptical-disktechnology,alaserbeamaltersthesurfaceofaplasticormetallicdisktorepresentdata.Toreadthedata,alaserscanstheseareasandsendsthedatatoacomputerchipforconversion.(4)MagneticTapeMagnetictapeisaneffectivewayofmakingabackup,orduplicate,copyofyourprogramsanddata.Wementionedthealarmingconsequencesthatcanhappenifaharddisksuffersaheadcrash.Youwilllosesomeorallofyourdataorprograms.Ofcourse,youcanalwaysmakecopiesofyourhard-diskfilesonfloppydisks.However,thiscanbetime-consumingandmayrequiremanyfloppydisks.Magnetictapeissequentialaccessstorageandcansolvetheproblemmentionedabove.WordsandExpressionsstorage[’st?:rid?]n.存儲，存儲器harddiskn.硬盤primarymemory主存儲器secondarymemory輔助存貯器temporarily['temp?r?rili]adv.臨時，暫時vanish[’v?ni?]vi.消失，消滅，消散repository[rip?zit?ri]n.存放處,儲藏室，倉庫accessible[?k’ses?bl]adj.容易取得的,容易達到的，可使用的instruction-fetchcycle取指令周期data-fetchcycle讀取數據周期WordsandExpressionsutilization[,ju:tilaizei??n]n.利用，使用,應用deallocate[di'?l?keit]v.解除分配,解除分配,釋放，歸還；重新分配metallic[mit?lik]adj.金屬性的,金屬(制)的,含金屬的plasticplatters塑料盤片read-writehead讀寫(磁)頭cushion[ku??n]n.軟墊,墊層;緩沖(墊);起緩沖作用的事物fingerprint[’fi?ɡ?print]n.指紋dust[d?st]n.灰塵,塵土,塵埃sterile[’sterail]adj.無菌的,消過毒的,無結果的,無益的cylinder[’silind?]n.圓筒,圓柱體rpm(revolutionsperminute)轉數／分，每分鐘轉動次數Floppydisks軟盤WordsandExpressionscassette[k?’set]n.盒式錄音帶,盒式錄像帶rectangular[rek’t??ɡjul?]adj.矩形的,長方形的，直角的rigid[’rid?id]adj.剛硬的，不彎曲的，嚴格的，嚴密的，剛性的mylar[’mailɑ:]n.聚脂薄膜electromagnetic[ilektr??'m?gnitik]adj.電磁的oxide[’?ksaid]n.氧化物，氧氣opticaldisk光盤，光碟laserbeam激光束CDs光盤,壓縮盤DVD數字化視頻光盤Magnetictape磁帶ExercisesI.Trueorfalse?Ifcorrect,writeTinparentheses;Otherwise,writeF.（）1.Memoryisalsoknownasprimarystorage,internalstorage,itpermanently.holdsdata,programinstructions,andinformation.（）2.Oneofthemostimportantfactstoknowaboutmemoryisthatallofitsc