history of computer.docx
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history of computer.docx
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historyofcomputer
Historyofcomputer
王振国
四川大学软件学院10级八班
【摘要】Nowadays,computershavedeeplyrootedineveryfieldsofourdailylifehoweverthehistoryofitisjustseveraldozensofyears.Likesomanyinventionsthroughouthistory,thecomputerevolvedasinventorstinkeredwithvariousdevices.Asaresult,itisdifficultforhistorianstopointtoonedevelopmentandsaythatitisthefirstcalculatororthefirstcomputer.
Keywords:
computer,history,development
1MANUALCALCULATORSEvenbeforerecordedhistory,humansusedcountingaids,suchaspebblesandnotchedsticks,tokeeptrackofquantities-thenumberofsheepinaflock,forexample,orthenumberofoiljarspurchasedfromamerchant.Manytransactions,howeverrerequiredcalculations.[1]
Acalculationisbasedonanalgorithm-thestep-by-stepprocessbywhichnumbersaremanipulated.Evensimplepaper-and-penciladditionrequiresanalgorithm.Thestepincludeaddingtherightmostdigitsfirst,carryinga1ifnecessary,andthenmovinglefttoanyremainingdigits.OthermanualcalculatorsincludetheoddlynamedNapier’sBonesandthesliderules.JohnNapier,theScottishLairdofMerchiston,madetwocontributionstothefieldofmath.HeinventedLOGARITHMSandadeviceformultiplicationanddivision.In1621,anEnglishmathematiciannamedWilliamOughtredusedNapier’slogarithmstoconstructthefirstsliderule.
2MECHANICALCALCULATORS
AselectionofMechanicalcalculators:
Thebasicoperatingprinciplesofmechanicalcalculatorschangedlittlefromtheendofthe19thcenturytotheirobsolescenceinthe1970s,thoughthereweremanydevelopmentsinthemechanismsandthematerialsused.Thissiteshowsrepresentativeexamplesofthedifferenttypes.
Modelsmadebeforetheendofthe19thcenturyareveryrareandareusuallyonlytobeseeninmuseumsandbooks.TheseincludethePascalineinventedbyBlaisePascal,andtheSteppedReckonerinventedbyLeibniz,bothinthe17thcentury,andCharlesXavierThomas'sArithmometerinthe19thcentury.
Themechanicalcalculatorsfeaturedherearetypicalmachineswhichwereoustedbythecheapelectroniccalculatorswhichweregraduallydevelopedduringthe1960sandearly1970s.[2]
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3COMPTERPROTOTYPES
Thesecondworldwar,theUnitedStatesasAllies,participatedinthewar.Americanarmyrequirements,universityofPennsylvaniaDianGongXiMohrinstituteandAberdeenballisticresearchlaboratories,everydayZhangHuoLitabletogetherprovidesix.Eachtableistocalculatethehundreds,thisworkisheavyballisticandpressing.Usedesktopcalculatorcalculationfor60secondsaflighttimeballisticandthefastestalsoget20hours,ifuselargecalculusanalyzercalculationsto15minutes.Aberdeenlaboratorywashiredmorethan200calculationexpert,evenso,afiretablealsooftenwanttocalculatetwoorthreemonths,cannotsatisfyoperationalrequirements.
Inordertogetridofthiskindofnegativesituation,rapidlydevelopedonecanimprovethecomputationalpower,speedmethodsandtoolsiscritical.Thenledtheresearchworkofthechiefengineeroftheyearonly23yearsold,he'sbeengramswithmanyscientistscooperation,aftermorethantwoyearsefforts,andfinally,ontheendof1945,manufacturingsuccessintheworldthefirstelectroniccomputer,named"ENIAC",theabbreviationENIAC.
Thismachineamazingelectroniccomputerislikeacolossus,thereare18000tubes,coversanareaof170squaremeters,weigh30tons.Everysecondcando5000timesadditionor400timesmultiplication,itthanthepastwithdesktopcalculatortocalculateballistic,quick2000tomanytimes.Fromthenon,humansinincomputinghasenteredacompletelynewera.
4 THEFIVEGENERATIONSOFCOMPUTERSEachgenerationofcomputerischaracterizedbyamajortechnologicaldevelopmentthatfundamentallychangedthewaycomputersoperate,resultinginincreasinglysmaller,cheaper,morepowerfulandmoreefficientandreliabledevices.
Thehistoryof computer developmentisoftenreferredtoinreferencetothedifferentgenerationsofcomputing devices.Eachgenerationofcomputerischaracterizedbyamajortechnologicaldevelopmentthatfundamentallychangedthewaycomputersoperate,resultinginincreasinglysmaller,cheaper,morepowerfulandmoreefficientandreliabledevices.Readabouteachgenerationandthedevelopmentsthatledtothecurrentdevicesthatweusetoday.
FirstGeneration(1940-1956)VacuumTubes
Thefirstcomputersusedvacuumtubesforcircuitryandmagneticdrums for memory,andwereoftenenormous,takingupentirerooms.Theywereveryexpensivetooperateandinadditiontousingagreatdealofelectricity,generatedalotofheat,whichwasoftenthecauseofmalfunctions.
Firstgenerationcomputersreliedon machinelanguage,thelowest-levelprogramminglanguageunderstoodbycomputers,toperformoperations,andtheycouldonlysolveoneproblematatime.Inputwasbasedonpunchedcardsandpapertape,andoutputwasdisplayedonprintouts.
TheUNIVACand ENIAC computersareexamplesoffirst-generationcomputingdevices.TheUNIVACwasthefirstcommercialcomputerdeliveredtoabusinessclient,theU.S.CensusBureauin1951.
SecondGeneration(1956-1963)Transistors
Transistors replacedvacuumtubesandusheredinthesecondgenerationofcomputers.Thetransistorwasinventedin1947butdidnotseewidespreaduseincomputersuntilthelate1950s.Thetransistorwasfarsuperiortothevacuumtube,allowingcomputerstobecomesmaller,faster,cheaper,moreenergy-efficientandmorereliablethantheirfirst-generationpredecessors.Thoughthetransistorstillgeneratedagreatdealofheatthatsubjectedthecomputertodamage,itwasavastimprovementoverthevacuumtube.Second-generationcomputersstillreliedonpunchedcardsforinputandprintoutsforoutput.
Second-generationcomputersmovedfromcryptic binary machinelanguagetosymbolic,or assembly,languages,whichallowedprogrammerstospecifyinstructionsinwords. High-levelprogramminglanguages werealsobeingdevelopedatthistime,suchasearlyversionsof COBOL and FORTRAN.Thesewerealsothefirstcomputersthatstoredtheirinstructionsintheirmemory,whichmovedfromamagneticdrumtomagneticcoretechnology.
Thefirstcomputersofthisgenerationweredevelopedfortheatomicenergyindustry.
ThirdGeneration(1964-1971)IntegratedCircuits
Thedevelopmentofthe integratedcircuit wasthehallmarkofthethirdgenerationofcomputers.Transistorswereminiaturizedandplacedon silicon chips,calledsemiconductors,whichdrasticallyincreasedthespeedandefficiencyofcomputers.
Insteadofpunchedcardsandprintouts,usersinteractedwiththirdgenerationcomputersthrough keyboards and monitors and interfaced withan operatingsystem,whichallowedthedevicetorunmanydifferent applications atonetimewithacentralprogramthatmonitoredthememory.Computersforthefirsttimebecameaccessibletoamassaudiencebecausetheyweresmallerandcheaperthantheirpredecessors.
FourthGeneration(1971-Present)Microprocessors
The microprocessor broughtthefourthgenerationofcomputers,asthousandsofintegratedcircuitswerebuiltontoasinglesiliconchip.Whatinthefirstgenerationfilledanentireroomcouldnowfitinthepalmofthehand.TheIntel4004chip,developedin1971,locatedallthecomponentsofthecomputer—fromthe centralprocessingunit andmemorytoinput/outputcontrols—onasinglechip.
In1981 IBM introduceditsfirstcomputerforthehomeuser,andin1984 AppleintroducedtheMacintosh.Microprocessorsalsomovedoutoftherealmofdesktopcomputersandintomanyareasoflifeasmoreandmoreeverydayproductsbegantousemicroprocessors.
Asthesesmallcomputersbecamemorepowerful,theycouldbelinkedtogethertoformnetworks,whicheventuallyledtothedevelopmentoftheInternet.Fourthgenerationcomputersalsosawthedevelopmentof GUIs,the mouse andhandheld devices.
FifthGeneration(PresentandBeyond)ArtificialIntelligence
Fifthgenerationcomputingdevices,basedon artificialintelligence,arestillindevelopment,thoughtherearesomeapplications,suchas voicerecognition,thatarebeingusedtoday.Theuseof parallelprocessing andsuperconductorsishelpingtomakeartificialintelligenceareality. Quantumcomputation andmolecularand nanotechnology willradicallychangethefaceofcomputersinyearstocome.Thegoaloffifth-generationcomputingistodevelopdevicesthatrespondto naturallanguage inputandarecapableoflearningandself-organization.[3]
Ref:
[1]NewPerspectivesonComputerConceptsComprensive(EighthEdition)sectionACHAPTER8
[2]
[3]
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