【文章內(nèi)容簡介】 asamediumsizedputerusedbymanybusinesses.RemintongRand,現(xiàn)在叫做 SperrRand公司 ,制造了一些第二代 UNIVAC計算機。然而， IBM繼續(xù)稱霸計算機行業(yè)。最流行的第二代計算機之一是IBM1401,這是一部許多企業(yè)使用的中型計算機。Allputersatthistimeweremainframeputerscostingoveramilliondollars.Thefirstminiputerbecameavailablein1960andcostabout$120,000.ThiswasthePDP1,manufacturedbyDigitalEquipmentCorporation(DEC).當(dāng)時所有的計算機都是價值百萬元以上的大型計算機。第一臺小型計算機產(chǎn)生于 1960年，價值 12萬美元，它就是由數(shù)據(jù)設(shè)備公司 (DEC)制造的 PDP1。 19計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersComputerGenerations SecondGeneration Computers: 1959～ 1963Softwarealsocontinuedtodevelopduringthistime.Manynewprogramminglanguagesweredesigned,includingCOBOLin1960.Moreandmorebusinessesandanizationswerebeginningtouseputersfortheirdataprocessingneeds.在此期間軟件也在繼續(xù)發(fā)展。許多新的編程語言被發(fā)明 ,包括1960年發(fā)明的 COBOL。越來越多的企業(yè)和組織開始使用計算機以滿足他們的數(shù)據(jù)處理需要。 20計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersComputerGenerationsThirdGenerationComputers:1964～ 1970ThetechnicaldevelopmentthatmarksthethirdgenerationofputersistheuseofintegratedcircuitsorICsinputers.Anintegratedcircuitisapieceofsilicon(achip)containingnumeroustransistors.OneICreplacesmanytransistorsinaputer。resultinacontinuationofthetrendsbeguninthesecondgeneration.Thesetrendsincludereducedsize,reducedcost,increasedspeed,andreducedneedforairconditioning.作為第三代計算機標(biāo)志的技術(shù)發(fā)展是在計算機中使用集成電路或簡稱 IC。一個集成電路就是包含許多晶體管的一個硅片 (芯片 )。一個集成電路代替了計算機中的許多晶體管，導(dǎo)致了始于第二代的一些趨勢的繼續(xù)。這些趨勢包括計算機體積減小、成本降低、速度提高和對空調(diào)的需要減少。 21計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersComputerGenerationsThirdGenerationComputers:1964～ 1970Althoughintegratedcircuitswereinventedin1958,thefirstputerstomakeextensiveuseofthemwerenotavailableuntil1964.Inthatyear,IBMintroducedalineofmainframeputerscalledtheSystem/360.Theputersinthislinebecamethemostwidelyusedthirdgenerationmachines.ThereweremanymodelsintheSystem/360line,rangingfromsmall,relativelyslow,andinexpensiveones,tolarge,veryfast,andcostlymodels.Allmodels,however,werepatiblesothatprogramswrittenforonemodelcouldbeusedonanother.Thisfeatureofpatibilityacrossmanyputersinalinewasadoptedbyothermanufacturersofthirdgenerationputers. 雖然集成電路發(fā)明于 1958年 ,但是直到 1964年才出現(xiàn)了第一臺廣泛使用 IC的計算機。那一年， IBM推出了稱為 System/360的大型計算機系列。這一系列的計算機成為使用最廣泛的第三代計算機。在 System/360系列中有許多機型 , 從小型的、相對較慢的且價格低廉的機型，到大型的、非?？斓那覂r格昂貴的機型。然而 ,所有的機型都是兼容的，以便在一個機型上編寫的程序可以用于另一個機型。這個在許多計算機系列間兼容的特征被其他第三代計算機制造商所采用。 22計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersThirdGenerationComputers:1964～ 1970Thethirdputergenerationwasalsothetimewhenminiputersbecamewidespread.ThemostpopularmodelwasthePDP8,manufacturedbyDEC.Otherpanies,includingDataGeneralCorporationandHewlettPackardCompany, introduced miniputers during the thirdgeneration.計算機的第三代也是小型計算機普及的時代。最流行的小型機是由 DEC制造的 PDP8。其他公司 ,包括數(shù)據(jù)通用公司和惠普(HewlettPackard)公司 ,在第三代期間開發(fā)了小型計算機。 ComputerGenerations23計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersThirdGenerationComputers:1964～ 1970Theprincipalsoftwaredevelopmentduringthethirdputergenerationwastheincreasedsophisticationofoperatingsystems.Althoughsimpleoperating systems were developed for firstand secondgenerationputers,manyofthefeaturesofmodernoperatingsystemsfirstappearedduringthethirdgeneration.Theseincludemultiprogramming,virtualmemory,andtimesharing.Thefirstoperatingsystemsweremainlybatchsystems,butduringthethirdgeneration,interactivesystems,especiallyonminiputers,becamemon.TheBASICprogramminglanguagewasdesignedin1964andbecamepopularduringthethirdputergenerationbecauseofitsinteractivenature.在第三代計算機期間，軟件的主要發(fā)展是操作系統(tǒng)的復(fù)雜化程度提高。雖然為第一代和第二代計算機開發(fā)了簡單的操作系統(tǒng) ,許多現(xiàn)代操作系統(tǒng)的特征首先在第三代期間出現(xiàn)。這些特征包括多道程序設(shè)計、虛擬存儲和分時技術(shù)。第一代操作系統(tǒng)主要是批處理系統(tǒng) ,但是在第三代期間，交互式系統(tǒng)開始普及，尤其是在小型計算機上。 BASIC語言發(fā)明于 1964年，并由于其交互式特征而在第三代計算機期間大為流行。ComputerGenerations24計算機專業(yè)英語Chapter1TheHistoryandFutureofComputers FourthGeneration Computers: 1971～ ?The fourth generation of puters is more difficult to define than the other three generations. This generation is characterized by more and more transistors being contained on a silicon chip. First there was Large Scale Integration (LSI), with hundreds and thousands of transistors per chip, then came Very Large Scale Integration (VLSI), with tens of thousands and hundreds of thousands of transistors. The trend continues today.第四代計算機比其他三代更難以定義。這一代計算機的特征是一個芯片上包含越來越多的晶體管。首先，出現(xiàn)了一個芯片上具有數(shù)百和數(shù)千個晶體管的大規(guī)模集成電路 (LSI)，接著出現(xiàn)了一個芯片上具有數(shù)萬和數(shù)十萬個晶體管的超大規(guī)模集成電路(VLSI)。這個趨勢在今天仍在持續(xù) 。ComputerGenerations25計算機專業(yè)英語Chapter1TheHistoryandFutureofComputers FourthGeneration Computers: 1971～ ?Although not everyone agrees that there is a fourth puter generation, those that do feel that it began in 1971, when IBM introduced its successors to the System/360 line of puters. These mainframe puters were called the System/370, and currentmodel IBM puters, although not called System/370s, evolved directly from these puters. 雖然并不是每個人都同意存在一個第四代 ,那些認(rèn)為存在的覺得它開始于1971年，其時 IBM開發(fā)了 System/360系列計算機的下一系列產(chǎn)品。這些大型計算機稱為 System/370,當(dāng)前的 IBM計算機雖然不叫做 System/370，但都是從這些計算機直接發(fā)展而來的。Miniputers also proliferated during the fourth puter generation. The most popular lines were the DEC PDP11 models and the DEC VAX, both of which are available in various models today. 小型計算機也在第四代期間迅速增長。最流行的系列是 DEC公司的 PDP11機和 DEC的 VAX機 ,二者在今天的各種機型中仍然有效。 ComputerGenerations26計算機專業(yè)英語Chapter1TheHistoryandFutureofComputersComputerGenerations FourthGeneration Computers: 1971～ ?Superputers first became prominent in the fourthgeneration.Althoughmanypanies,includingIBMandCDC,developedhighspeedputersforscientificwork,itwasnotuntilCrayResearch,Inc.,introducedtheCray1in1975 that superputers became significant. Today,superputersareanimportant160