计算机专业英语课件unit1A

UnitOne

ComputerOverviewWordsandphrasesalgorithmn.算法

operatev.操作

digitaladj.数字的

integratedcircuit集成电路chipn.芯片

PC个人电脑embedsystem嵌入式系统

sensor n.传感器quantumn.量子Computerscienceisthedisciplinethatseekstobuildascientificfoundationforsuchtopicsascomputerdesign,computerprogramming,informationprocessing,algorithmicsolutionsofproblems,andthealgorithmicprocessitself.Itprovidestheunderpinningsfortoday’scomputerapplicationsaswellasthefoundationsfortomorrow’scomputinginfrastructure.1.History(1)Abacus

Themachineisquitesimple,consistingofbeadsstrungonrodsthatareinturnmountedinarectangularframe.Asthebeadsaremovedbackandforthontherods,theirpositionsrepresentstoredvalues.Forcontrolofanalgorithm’sexecution,themachinereliesonthehumanoperator.Thustheabacusaloneismerelyadatastoragesystem.BlaisePascal,19June1623–19August1662)wasaFrenchmathematician,physicist,inventor,writer.AddingMachine(2)AddingMachineThisdeviceemployedaseriesoften-toothedwheels,eachtoothrepresentingadigitfrom0to9,withdatabeinginputmechanicallybyestablishinginitialgearpositions.Outputwasachievedbyobservingthefinalgearpositions.GottfriedWilhelmLeibniz,1July1646–November14,1716)wasaGermanpolymath,mathematicianandphilosopher.(3)DifferenceEngine、AnalyticalEngineAnalyticalEnginewasdesignedtoreadinstructionsintheformofholesinpapercards.

DifferenceEngineAnalyticalEngineThusBabbage’sAnalyticalEnginewasprogrammable.Infact,

AugustaAdaByron,whopublishedapaperinwhichshedemonstrated

howBabbage’sAnalyticalEnginecouldbeprogrammedtoperformvarious

computations,isoftenidentifiedtodayastheworld’sfirstprogrammer.AugustaAdaByronAlanTuring

CharlesBabbagewasanEnglishpolymath.Amathematician,philosopher,inventorandmechanicalengineer,Babbage,alongwithAdaByron,isbestrememberedfororiginatingtheconceptofaprogrammablecomputer.TuringTest（4）ElectronicComputerThetechnologyofthetimewasunabletoproducethecomplexgear-drivenmachinesofPascal,Leibniz,andBabbageinafinanciallyfeasiblemanner.Butwiththeadvancesinelectronicsintheearly1900s,thisbarrierwasovercome.Someresearcherswereapplyingthetechnologyofvacuumtubestoconstructtotallyelectroniccomputers.

Atanasoff-Berrymachine

ThefirstofthesemachineswasapparentlytheAtanasoff-Berrymachine,constructedduringtheperiodfrom1937to1941atIowaStateCollegebyJohnAtanasoffandhisassistant,CliffordBerry.Colossus

AnotherwasamachinecalledColossus,usedbytheteamheadedbyAlanTuringtodecodeGermanmessagesduringthelatterpartofWorldWarII.ENIACOther,moreflexiblemachineswasdeveloped,suchastheENIAC(electronicnumericalintegratorandcalculator).（5）IntegratedCircuitsThehistoryofcomputingmachineshasbeencloselylinkedtoadvancingtechnology,includingtheinventionoftransistorsandthesubsequentdevelopmentofcircuitsconstructedassingleunits,calledintegratedcircuits.Withthesedevelopments,theroom-sizedmachinesofthe1940swerereducedoverthedecadestothesizeofsinglecabinetswhiletheprocessingpowerofcomputingmachinesbegantodoubleeverytwoyears.Asworkonintegratedcircuitryprogressed,manyofthecircuitswithinacomputerbecamereadilyavailableontheopenmarketasintegratedcircuitsencasedintoy-sizedblocksofplasticcalledchips.2.ModernComputerpersonalcomputerDesktopLaptopPalmtop/tabletMicrocomputerWorkstationMinicomputerMainframesupercomputerDesktopAmajorsteptowardpopularizingcomputingwasthedevelopmentofdesktopcomputers.In1981,IBMintroduceditsfirstdesktopcomputer,calledthepersonalcomputer,orPC,whoseunderlyingsoftwarewasdevelopedbyanewlyformedcompanyknownasMicrosoft.ThePCwasaninstantsuccess.Today,thetermPCiswidelyusedtorefertoallthosemachines(fromvariousmanufacturers)whosedesignhasevolvedfromIBM’sinitialdesktopcomputer.Attimes,however,thetermPCisusedinterchangeablywiththegenerictermsdesktoporlaptop.InternetAsthetwentiethcenturydrewtoaclose,theabilitytoconnectindividualcomputersinaworld-widesystemcalledtheInternetwasrevolutionizingcommunication.ABritishscientistTimBerners-LeeproposedasystembywhichdocumentsstoredoncomputersthroughouttheInternetcouldbelinkedtogetherproducingamazeoflinkedinformationcalledtheWorldWideWeb(shortenedto“Web”).

TomaketheinformationontheWebaccessible,softwaresystems,calledsearchengines,weredevelopedto“siftthrough”theWeb,“categorize”theirfindings,andthenusetheresultstoassistusersresearchingparticulartopics.EmbeddedAsthedesktopcomputerswerebeingacceptedandusedinhomes,theminiaturizationofcomputingmachinescontinued.Today,tinycomputersareembeddedwithinvariousdevices.Forexample,automobilesnowcontainsmallcomputersrunningGlobalPositioningSystems(GPS),monitoringthefunctionoftheengine,andprovidingvoicecommandservicesforcontrollingthecar’saudioandphonecommunicationsystems.3.SmartphonePerhapsthemostpotentiallyrevolutionaryapplicationofcomputerminiaturizationisfoundintheexpandingcapabilitiesofportabletelephones.Recently,merelyatelephonehasevolvedintoasmallhand-heldgeneralpurposecomputerknownasasmartphoneonwhichtelephonyisonlyoneofmanyapplications.These“phones”areequippedwitharicharrayofsensorsandinterfacesincludingcameras,microphones,compasses,touchscreens,accelerometers(todetectthephone’sorientationandmotion),andanumberofwirelesstechnologiestocommunicatewithothersmartphonesandcomputers.Thepotentialisenormous.Indeed,manyarguethatthesmartphonewillhaveagreatereffectonsocietythanthePC.Theminiaturizationofcomputersandtheirexpandingcapabilitieshavebroughtcomputertechnologytotheforefrontoftoday’ssociety.Computertechnologyissoprevalentnowthatfamiliaritywithitisfundamentaltobeingamemberofmodernsociety.Computingtechnologyhasalteredtheabilityofgovernmentstoexertcontrol;hadenormousimpactonglobaleconomics;ledtostartlingadvancesinsci