【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(jì)算機(jī)。然而， IBM繼續(xù)稱霸計(jì)算機(jī)行業(yè)。最流行的第二代計(jì)算機(jī)之一是IBM1401,這是一部許多企業(yè)使用的中型計(jì)算機(jī)。Allputersatthistimeweremainframeputerscostingoveramilliondollars.Thefirstminiputerbecameavailablein1960andcostabout$120,000.ThiswasthePDP1,manufacturedbyDigitalEquipmentCorporation(DEC).當(dāng)時(shí)所有的計(jì)算機(jī)都是價(jià)值百萬元以上的大型計(jì)算機(jī)。第一臺小型計(jì)算機(jī)產(chǎn)生于 1960年，價(jià)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(jì)算機(jī)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(jì)算機(jī)以滿足他們的數(shù)據(jù)處理需要。 20計(jì)算機(jī)專業(yè)英語Chapter1TheHistoryandFutureofComputersComputerGenerationsThirdGenerationComputers:1964～ 1970ThetechnicaldevelopmentthatmarksthethirdgenerationofputersistheuseofintegratedcircuitsorICsinputers.Anintegratedcircuitisapieceofsilicon(achip)containingnumeroustransistors.OneICreplacesmanytransistorsinaputer。resultinacontinuationofthetrendsbeguninthesecondgeneration.Thesetrendsincludereducedsize,reducedcost,increasedspeed,andreducedneedforairconditioning.作為第三代計(jì)算機(jī)標(biāo)志的技術(shù)發(fā)展是在計(jì)算機(jī)中使用集成電路或簡稱 IC。一個(gè)集成電路就是包含許多晶體管的一個(gè)硅片 (芯片 )。一個(gè)集成電路代替了計(jì)算機(jī)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(jì)算機(jī)體積減小、成本降低、速度提高和對空調(diào)的需要減少。 21計(jì)算機(jī)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(jì)算機(jī)。那一年， IBM推出了稱為 System/360的大型計(jì)算機(jī)系列。這一系列的計(jì)算機(jī)成為使用最廣泛的第三代計(jì)算機(jī)。在 System/360系列中有許多機(jī)型 , 從小型的、相對較慢的且價(jià)格低廉的機(jī)型，到大型的、非常快的且價(jià)格昂貴的機(jī)型。然而 ,所有的機(jī)型都是兼容的，以便在一個(gè)機(jī)型上編寫的程序可以用于另一個(gè)機(jī)型。這個(gè)在許多計(jì)算機(jī)系列間兼容的特征被其他第三代計(jì)算機(jī)制造商所采用。 22計(jì)算機(jī)專業(yè)英語Chapter1TheHistoryandFutureofComputersThirdGenerationComputers:1964～ 1970Thethirdputergenerationwasalsothetimewhenminiputersbecamewidespread.ThemostpopularmodelwasthePDP8,manufacturedbyDEC.Otherpanies,includingDataGeneralCorporationandHewlettPackardCompany, introduced miniputers during the thirdgeneration.計(jì)算機(jī)的第三代也是小型計(jì)算機(jī)普及的時(shí)代。最流行的小型機(jī)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(jì)算機(jī)。 ComputerGenerations23計(jì)算機(jī)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(jì)算機(jī)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(jì)算機(jī)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(jì)、虛擬存儲(chǔ)和分時(shí)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(jì)算機(jī)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(jì)算機(jī)期間大為流行。ComputerGenerations24計(jì)算機(jī)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(jì)算機(jī)比其他三代更難以定義。這一代計(jì)算機(jī)的特征是一個(gè)芯片上包含越來越多的晶體管。首先，出現(xiàn)了一個(gè)芯片上具有數(shù)百和數(shù)千個(gè)晶體管的大規(guī)模集成電路 (LSI)，接著出現(xiàn)了一個(gè)芯片上具有數(shù)萬和數(shù)十萬個(gè)晶體管的超大規(guī)模集成電路(VLSI)。這個(gè)趨勢在今天仍在持續(xù) 。ComputerGenerations25計(jì)算機(jī)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(gè)人都同意存在一個(gè)第四代 ,那些認(rèn)為存在的覺得它開始于1971年，其時(shí) IBM開發(fā)了 System/360系列計(jì)算機(jī)的下一系列產(chǎn)品。這些大型計(jì)算機(jī)稱為 System/370,當(dāng)前的 IBM計(jì)算機(jī)雖然不叫做 System/370，但都是從這些計(jì)算機(jī)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(jì)算機(jī)也在第四代期間迅速增長。最流行的系列是 DEC公司的 PDP11機(jī)和 DEC的 VAX機(jī) ,二者在今天的各種機(jī)型中仍然有效。 ComputerGenerations26計(jì)算機(jī)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