計(jì)算機(jī)文化、程序設(shè)計(jì)

計(jì)算概論-計(jì)算機(jī)文化、程序設(shè)計(jì)IntroductiontoComputing:ComputerCulture,andProgramming閆宏飛陳卿編著byHongfeiYanandChongChen2010/9/23內(nèi)容簡(jiǎn)介本書主要是匯編各書和參考資料而成，比較系統(tǒng)地介紹了計(jì)算機(jī)文化，和程序設(shè)計(jì)。通過這兩部分有機(jī)的結(jié)合（前者占1/3,后者占2/3）,即理論與實(shí)踐結(jié)合，使學(xué)生理解和掌握有關(guān)計(jì)算機(jī)和信息技術(shù)的基本概念和基本原理，對(duì)計(jì)算機(jī)學(xué)科有全局性的認(rèn)識(shí)；學(xué)會(huì)使用計(jì)算機(jī)進(jìn)行信息處理，熟練掌握C++語言編程技術(shù)，為后續(xù)相關(guān)課程的學(xué)習(xí)打好基礎(chǔ)。本書層次分明，由淺入深，具有學(xué)習(xí)和實(shí)用雙重意義。本書可作為高等院校各專業(yè)一、二年級(jí)學(xué)生的教學(xué)參考書和技術(shù)資料，對(duì)廣大從事計(jì)算機(jī)相關(guān)研究和應(yīng)用開發(fā)的科技人員也有很大的參考價(jià)值。**刖R《計(jì)算概論》是普通高校面向理工科低年級(jí)學(xué)生開設(shè)的計(jì)算機(jī)基礎(chǔ)教育課。課程前1/3部分為計(jì)算機(jī)文化，后2/3部分為程序設(shè)計(jì)。任教此課兩年來，發(fā)現(xiàn)沒有合適的教材，因此根據(jù)授課經(jīng)驗(yàn)，匯編各書和參考資料，編成此書。編者2009年1月于北大燕園hITbTOC\o"1-5"\h\z\o"CurrentDocument"第1章引論. 1\o"CurrentDocument"計(jì)科學(xué) 2\o"CurrentDocument"摩爾定律 3\o"CurrentDocument"ScopeofProblems 5計(jì)《i化 9第2章統(tǒng) 10\o"CurrentDocument"ComputerIntroduction 10\o"CurrentDocument"TURINGMODEL 11\o"CurrentDocument"VONNEUMANNMODEL 16\o"CurrentDocument"Computercomponents 18\o"CurrentDocument"History 19\o"CurrentDocument"Practiceset 24\o"CurrentDocument"計(jì)射L系統(tǒng)漫游 25\o"CurrentDocument"InformationisBits+Context 27\o"CurrentDocument"ProgramsAreTranslatedbyOtherProgramsintoDifferentForms 29\o"CurrentDocument"ItPaystoUnderstandHowCompilationSystemsWork 31\o"CurrentDocument"ProcessorsReadandInterpretInstructionsStoredinMemory 32\o"CurrentDocument"CachesMatter 38\o"CurrentDocument"StorageDevicesFormaHierarchy 39\o"CurrentDocument"TheOperatingSystemManagestheHardware 40\o"CurrentDocument"SystemsCommunicateWithOtherSystemsUsingNetworks 47\o"CurrentDocument"TheNextStep 49第3章和數(shù)的^zj^??????????????????????????????????????????????????????????????????????????????????????????????????????????????52\o"CurrentDocument"數(shù)據(jù)的表示 52數(shù)的表示 66\o"CurrentDocument"第4章程序設(shè)計(jì)語言和開發(fā)環(huán)境 70?Wtig言 70)I*???*?????????????????????????+?+???+?***,+?*?+?*?+?+???*?*???*?+???+?+?+?+?+?+?d???3?*???*?.8^)下篇出設(shè)計(jì) 86第5章 87GettingStarted 87FundamentalTypes 91ArithmeticOperator 100\o"CurrentDocument"ControlStructures 123第6章M和結(jié)構(gòu) 153\o"CurrentDocument"6.1數(shù)組 153Initializingarrays ! 未定義書簽。Accessingthevaluesofanarray ! 未定義書簽。Multidimensionalarrays ! 未定義書簽。6.2結(jié)構(gòu) 164Datastructures 錯(cuò)誤！未定義書簽。Pointerstostructures ! 未定義書簽。Nestingstructures ! 未定義書簽。\o"CurrentDocument"Quiz:Structures 199\o"CurrentDocument"第7章C++標(biāo)準(zhǔn)庫 205\o"CurrentDocument"CLanguagelibrary 206\o"CurrentDocument"Input/OutputStreamlibrary 207\o"CurrentDocument"Stringlibrary 208\o"CurrentDocument"STL:StandardTemplateLibrary 208第8章函數(shù)和遞歸 錯(cuò)誤！未定義書簽。Functionswithnotype.Theuseofvoid 錯(cuò)誤!未定義書簽。Argumentspassedbyvalueandbyreference !未定義書簽。Default\aluesinmrameters !未定義書簽。Overloadedfunctions !未定義書簽。INLINEFUNCTIONS 未定義書簽。RECURSIVITY 未定義書簽。Declaringfunctions 未定義書簽。inTOC\o"1-5"\h\z\o"CurrentDocument"Referenceoperator(&) 212\o"CurrentDocument"Dereferenceoperator(*) …… 214\o"CurrentDocument"Declaringvariablesofpointertypes 215\o"CurrentDocument"Pointersandarrays 218\o"CurrentDocument"Pointerinitialization 220\o"CurrentDocument"Pointerarithmetics 221\o"CurrentDocument"Pointerstopointers 223\o"CurrentDocument"voidpointers 224\o"CurrentDocument"Nullpointer 225\o"CurrentDocument"Pointerstofunctions 226\o"CurrentDocument"9.2DYNAMICMomory 227\o"CurrentDocument"Operatorsnewandnew[] 227\o"CurrentDocument"Operatorsdeleteanddeletc[] 229\o"CurrentDocument"DynamicmemoryinANSI-C 231第10章VARIABLES:ADEEPERLOOK 232\o"CurrentDocument"10JMemoryorganization 232\o"CurrentDocument"VARIABLESCOPE 234\o"CurrentDocument"Understandingpointers 235\o"CurrentDocument"第11章算法 238\o"CurrentDocument"TheRoleofAlgorfthmsinComputing 239\o"CurrentDocument"Algorithms 239\o"CurrentDocument"Algorithmsasatechnology 244算法的概念 247算法的三種基本結(jié)構(gòu) 247算法的表示 248介紹幾種基本算法 248迭代與遞歸 248第12章齡設(shè)計(jì) 249簡(jiǎn)單計(jì)算題 249模擬 249可模型化的問題 250\o"CurrentDocument"Introduction(Beginner) 251\o"CurrentDocument"Elementary 254\o"CurrentDocument"Intermediate 255\o"CurrentDocument"Upper-Intermediate 257\o"CurrentDocument"Advanced 258\o"CurrentDocument"參考文獻(xiàn) 262第1章引論計(jì)算機(jī)文化這個(gè)詞的出現(xiàn)到被廣泛認(rèn)可的時(shí)間并無確切的考證，但基本上是在20世紀(jì)80年代后期。計(jì)算機(jī)開始是一種裝置，進(jìn)而到一門學(xué)科，再發(fā)展成為一種“文化”，它對(duì)人類的影響力之大的確令人驚嘆。計(jì)算機(jī)文化是指能夠理解計(jì)算機(jī)是什么，以及它如何被作為資源使用的。簡(jiǎn)單地說，計(jì)算機(jī)文化不但是知道如何使用計(jì)算機(jī)，更重要的是知道什么時(shí)候使用計(jì)算機(jī)。在當(dāng)今世界，幾乎所有專業(yè)都與計(jì)算機(jī)息息相關(guān)。但是，只有某些特定職業(yè)和學(xué)科才會(huì)深入研究計(jì)算機(jī)本身的制造、編程和使用技術(shù)。用來詮釋計(jì)算機(jī)學(xué)科內(nèi)不同研究領(lǐng)域的各個(gè)學(xué)術(shù)名詞的涵義不斷發(fā)生變化，同時(shí)新學(xué)科也層出不窮。五個(gè)主要的計(jì)算機(jī)學(xué)科(disiplineofcomputing)包括1?計(jì)算機(jī)工程學(xué)(ComputerEngineering),是電子工程的一個(gè)分支，主要研究計(jì)算機(jī)軟硬件和二者間的彼此聯(lián)系。?計(jì)算機(jī)科學(xué)(ComputerScience),是對(duì)計(jì)算機(jī)進(jìn)行學(xué)術(shù)研究的傳統(tǒng)稱謂。主要研究計(jì)算技術(shù)和執(zhí)行特定任務(wù)的高效算法。該門學(xué)科為我們解決確定一個(gè)問題在計(jì)算機(jī)領(lǐng)域內(nèi)是否可解，如可解其效率圳何，以及如何作成更加高效率的程序。時(shí)至今日，在計(jì)算機(jī)科學(xué)內(nèi)已經(jīng)派生了許多分支,每一個(gè)分支都針對(duì)不同類別的問題進(jìn)行深入研究。軟件工程學(xué)(SoftwareEngineering),著重于研究開發(fā)高質(zhì)量軟件系統(tǒng)的方法學(xué)和實(shí)踐方式，并試圖壓縮并預(yù)測(cè)開發(fā)成本及開發(fā)周期。信息系統(tǒng)(InfbrmationSystems),研究計(jì)算機(jī)在一個(gè)廣泛的有組織環(huán)境(商業(yè)為主)中的計(jì)算機(jī)應(yīng)用。信息技術(shù)(InfbrmationTechnology),指計(jì)算機(jī)相關(guān)的管理和維護(hù)?！队?jì)算概論》課程關(guān)注的是計(jì)算機(jī)學(xué)科。較大規(guī)模的致力于計(jì)算機(jī)科學(xué)的組織有：美國計(jì)算機(jī)協(xié)會(huì)(AssociationofComputingMachinery,簡(jiǎn)稱ACM)；美國電氣電子工程師協(xié)會(huì)(InstituteofElectricalandElectronicsEngineers.簡(jiǎn)稱為IEEE)。1ComputingCurricula2005:TheOverviewReport,http:〃/education/curricvols/CC2005-March06Final.pdf計(jì)算機(jī)科學(xué)計(jì)算機(jī)科學(xué)是一門包含各種各樣與計(jì)算和信息處理相關(guān)主題的系統(tǒng)學(xué)科，從抽象的算法分析、形式化語法等等，到更具體的主題如編程語言、程序設(shè)計(jì)、軟件和硬件等。作為一門學(xué)科，它與數(shù)學(xué)、計(jì)算機(jī)程序設(shè)計(jì)、軟件工程和計(jì)算機(jī)工程有顯著的不同，卻通常被混清，盡管這些學(xué)科之間存在不同程度的交叉和覆蓋。2計(jì)算機(jī)科學(xué)研究的課題是：計(jì)算機(jī)程序能做什么和不能做什么（可計(jì)算性）；如何使程序更高效的執(zhí)行特定任務(wù)（算法和復(fù)雜性理論）；程序如何存取不同類型的數(shù)據(jù)（數(shù)據(jù)結(jié)構(gòu)和數(shù)據(jù)庫）；程序如何顯得更具有智能（人工智能）；人類如何與程序溝通（人機(jī)互動(dòng)和人機(jī)界面）。計(jì)算機(jī)科學(xué)的大部分研究是基于“馮?諾依曼計(jì)算機(jī)”和“圖靈機(jī)”的，它們是絕大多數(shù)實(shí)際機(jī)器的計(jì)算模型。作為此模型的開山鼻祖，邱奇-圖靈論題（Church-TuringThesis）表明，盡管在計(jì)算的時(shí)間，空間效率上可能有所差異，現(xiàn)有的各種計(jì)算設(shè)備在計(jì)算的能力上是等同的。盡管這個(gè)理論通常被認(rèn)為是計(jì)算機(jī)科學(xué)的基礎(chǔ)，可是科學(xué)家也研究其它種類的機(jī)器，如在實(shí)際層面上的并行計(jì)算機(jī)和在理論層面上概率計(jì)算機(jī)、oracle計(jì)算機(jī)和量子計(jì)算機(jī)。在這個(gè)意義上來講,計(jì)算機(jī)只是一種計(jì)算的工具：著名的計(jì)算機(jī)科學(xué)家Dijkstra有一句名言“計(jì)算機(jī)科學(xué)之關(guān)注于計(jì)算機(jī)并不甚于天文學(xué)之關(guān)注于望遠(yuǎn)鏡。計(jì)算機(jī)科學(xué)根植于電子工程、數(shù)學(xué)和語言學(xué)，是科學(xué)、工程和藝術(shù)的結(jié)晶。它在20世紀(jì)最后的三十年間興起成為一門獨(dú)立的學(xué)科，并發(fā)展出自己的方法與術(shù)語。早期，雖然英國的劍橋大學(xué)和其他大學(xué)已經(jīng)開始教授計(jì)算機(jī)科學(xué)課程，但它只被視為數(shù)學(xué)或工程學(xué)的一個(gè)分支，并非獨(dú)立的學(xué)科。劍橋大學(xué)聲稱有世界上第一個(gè)傳授計(jì)算的資格。世界上第一個(gè)計(jì)算機(jī)科學(xué)系是由美國的普渡大學(xué)在1962年設(shè)立，第一個(gè)計(jì)算機(jī)學(xué)院于1980年由美國的東北大學(xué)設(shè)立?，F(xiàn)在，多數(shù)大學(xué)都把計(jì)算機(jī)科學(xué)系列為獨(dú)立的部門，一部分將它與工程系、應(yīng)用數(shù)學(xué)系或其他學(xué)科聯(lián)合。計(jì)算機(jī)科學(xué)領(lǐng)域的最高榮譽(yù)是ACM設(shè)立的圖靈獎(jiǎng)，被譽(yù)為是計(jì)算機(jī)科學(xué)的諾貝爾獎(jiǎng)。它的獲得者都是本領(lǐng)域最為出色的科學(xué)家和先驅(qū)。華人中首獲圖靈獎(jiǎng)的是姚期智博士。他于2000年以其時(shí)計(jì)算理論做出的諸多''根本性的、意義重大的”貢獻(xiàn)而獲得這一崇高榮譽(yù)。http:〃/wiki/計(jì)算機(jī)科學(xué)

摩爾定律http:〃en.w汰/wiki/Moore%27sLawMoore'slawdescribesalong-termtrendinthehistoryofcomputinghardware.Sincetheinventionoftheintegratedcircuitin1958,thenumberoftransistorsthatcanbeplacedinexpensivelyonanintegratedcircuithasincreasedexponentially,doublingapproximatelyeverytwoyears.ThetrendwasfirstobservedbyIntelco-fbunderGordonE.Mooreina1965paper.lthascontinuedforalmosthalfofacenturyandisnotexpectedtostopforanotherdecadeatleastandperhapsmuchos-0一cnos-0一scnuall1,000,000,000—100,000,00010,000,0001,000,000—100,00010,0002,3001.1.、CurveshowsMoore'sLaw':transistorcountdoublingeverytwoyearsDateofintroduction圖CPUTransistorCounts1971-2008&Moore'sLaw,Growthoftransistorcounts

forIntelprocessors(dots)andMoore'sLaw(logarithmicverticalscale)AlmosteverymeasureofthecapabilitiesofdigitalelectronicdevicesislinkedtoMoore'slaw:processingspeed,memorycapacity,eventhenumberandsizeofpixelsindigitalcameras.Alloftheseareimprovingat(roughly)exponentialratesaswell.Thishasdramaticallyincreasedtheusefulnessofdigitalelectronicsinnearlyeverysegmentoftheworldeconomy.Moore'slawdescribesthisdrivingforceoftechnologicalandsocialchangeinthelate20thandearly21stcenturies./view/17904.htm計(jì)算機(jī)第一定律 摩爾定律Moore定律。歸納起來，主要有以下三種“版本”：集成電路芯片上所集成的電路的數(shù)目，每隔18個(gè)月就翻一番。微處理器的性能每隔18個(gè)月提高一倍，而價(jià)格下降一倍。用一個(gè)美元所能買到的電腦性能，每隔18個(gè)月翻兩番。圖1-2ComputerSpeedupMoore'sLaw:MThedensityoftransistorsonachipdoublesevery18months,farthesamecost半導(dǎo)體集成電路的密度或容量每18個(gè)月翻一番Moore'sLawisstillvalid.Hislawhasnothingtodowiththespeedoftheprocceso匚Ithastodowiththenumberoftransitotrswhichisstilldoubleingeverycoupleofyears.Caseinpointthereisnowmultiplecoresinthesamespaceinsteadofonecore.戈登?摩爾(GordonMoore),CPU生產(chǎn)商Intel公司的創(chuàng)始人之」1965年提出“摩爾定律”，1968年創(chuàng)辦Intel公司。摩爾1929年出生在美國加州的舊金山。曾獲得加州大學(xué)伯克利分校的化學(xué)學(xué)士學(xué)位，并且在加州理工大學(xué)(CIT)獲得物理和化學(xué)兩個(gè)博士學(xué)位。50年代中期他和集成電路的發(fā)明者羅伯特?諾伊斯(RobertNoyce)--起，在威廉?肖克利半導(dǎo)體公司工作。后來，諾伊斯和摩爾等8人集體辭職創(chuàng)辦了半導(dǎo)體工業(yè)史上有名的仙童半導(dǎo)體公司(FairchildSemiconductor)。仙童成為現(xiàn)在的Intel和AMD之父。1968年，摩爾和諾伊斯一起退出仙童公司，創(chuàng)辦了Intel。Intel初期致力于開發(fā)當(dāng)時(shí)計(jì)算機(jī)工業(yè)尚未開發(fā)的數(shù)據(jù)存儲(chǔ)領(lǐng)域，后來，Intel進(jìn)行戰(zhàn)略轉(zhuǎn)移，專攻微型計(jì)算機(jī)的''心臟”部件-CPU。1.3ScopeofProblemsWhatcanyoudowith1computer?Whatcanyoudowith100computers?Whatcanyoudowithanentiredatacenter?httD:〃en.wikiD/wiki/DistributedcomDuting#ProiectsProjects:Avarietyofdistributedcomputingprojectshavegrownupinrecentyears.Manyarerunonavolunteerbasis,andinvolveusersdonatingtheirunusedcomputationalpowertoworkoninterestingcomputationalproblems.ExamplesofsuchprojectsincludetheStanfordUniversityChemistryDepartmentFolding@homeproject,whichisfocusedonsimulationsofproteinfoldingtofinddiseasecuresandtounderstandbiophysicalsystems;WorldCommunityGrid,anefforttocreatetheworld*slargestpubliccomputinggridtotacklescientificresearchprojectsthatbenefithumanity,runandfundedbyIBM;SETI@home,whichisfocusedonanalyzingradio-telescopedatatofindevidenceofintelligentsignalsfromspace,hostedbytheSpaceSciencesLaboratoryattheUniversityofCalifornia,Berkeley(theBerkeleyOpenInfrastructureforNetworkComputing(BOINC),wasoriginallydevelopedtosupportthisproject);LHC@home,whichisusedtohelpdesignandtunetheLargeHadronCollider,hostedbyCERNinGeneva;and,whichisfocusedonfindingoptimalGolombrulersandbreakingvariouscryptographicciphers.http:〃/English/MainhtlD:〃zh.wikiD/wiki/Folding@homchttp:〃/grouD/DandegrouD/images/FAH?May2008.Dng

http:〃/folding/Folding@home是如何工作的呢？Folding@home是一個(gè)研究研究蛋白質(zhì)折疊，誤折，聚合及山此引起的相關(guān)疾病的分布式計(jì)算工程。使用聯(lián)網(wǎng)式的計(jì)算方式和大量的分布式計(jì)算能力來模擬蛋白質(zhì)折疊的過程，并指引我們近期對(duì)由折疊引起的疾病的一系列研究。圖1?3Folding@home

圖1-4Shrek?DreamworksAnimation,renderingmultipleframesofhigh-quality

animationHappyFeet?KingdomFeatureProductions;LordoftheRings?NewLineCinema圖1-5SimulatingseveralhundredorthousandcharactersIndexingtheweb(Google)Google()是一個(gè)搜索引擎，由兩個(gè)斯坦福大學(xué)博士生LarryPage與SergeyBrin于1998年9月發(fā)明,GoogleInc.于1999年創(chuàng)立。Google網(wǎng)頁搜索技術(shù)是來源于信息檢索技術(shù)。Google的“網(wǎng)頁快照”功能，能從Google服務(wù)器里直接取出緩存的網(wǎng)頁。SimulatinganInternet-sizednetworkfornetworkingexperiments(PlanetLab)http:〃/PlanetLabisaglobalresearchnetworkthatsupportsthedevelopmentofnewnetworkservices.Sincethebeginningof2003,morethan1,000researchersattopacademicinstitutionsandindustrialresearchlabshaveusedPlanetLabtodevelopnewtechnologiesfordistributedstorage,networkmapping,peer-to-peersystems,distributedhashtables,andqueryprocessing.PlanetLabcurrentlyconsistsof1128nodesat511sites.Speedingupcontentdelivery(Akamai)美國Akamai是國際上最大的CDN服務(wù)商，它巨大的網(wǎng)絡(luò)分發(fā)能力在峰值時(shí)可達(dá)到15Gbps?Akamai公司是為數(shù)不多的旨在消除Internet瓶頸和提高下載速度的幾家新公司之一，是一個(gè)致力于網(wǎng)絡(luò)交通提速的“內(nèi)容發(fā)布”公司，是波士頓高技術(shù)區(qū)最卓越的新興企業(yè)之一。Akamai公司向全球企業(yè)提供發(fā)送互聯(lián)網(wǎng)內(nèi)容，匯流媒體和應(yīng)用程序的服務(wù)(目前，該公司為15個(gè)國家的企業(yè)管理著8000多臺(tái)服務(wù)器）。1998年，丹尼爾.L和麻省理工學(xué)院的一些研究人員?起創(chuàng)立了這家公司,他在麻省理工學(xué)院的碩上論文構(gòu)成了Akamai公司最初的“自由流”（Freeflow）技術(shù)的核心。根據(jù)美國航空公司的消息，丹尼爾.L31歲，在2001年9月11H撞擊紐約世界貿(mào)易中心的被劫持飛機(jī)上遇難。上篇計(jì)算機(jī)文化上篇的主要目的是向讀者介紹有關(guān)計(jì)算機(jī)和信息技術(shù)的基本概念和基本原理，使讀者能夠?qū)τ?jì)算機(jī)學(xué)科有全局性的認(rèn)識(shí)。第2章計(jì)算機(jī)系統(tǒng)ComputerIntroduction本節(jié)大部分內(nèi)容取自下面這本書的第一章。等號(hào)線之間內(nèi)容是我加的。FoundationsofComputerScience,2e,byBehrouzForouzanandFirouzMosharraf.CcngagcLearningBusinessPress,December5,2007http:〃www.cengage.co.uk/forouzan/http:〃/Foundations?Computer-Science?Behrouz-Forouzan/dD/l844807002/reQsi3JdrbbproductThephrasecomputersciencehasaverybroadmeaningtoday.However,inthisbook,wedefinethephraseas“issuesrelatedtothecomputer0.Thisintroductorychapterfirsttriestofindoutwhatacomputeris,andtheninvestigatesotherissuesdirectlyrelatedtocomputers.WelookfirstattheTuringmodelasamathematicalandphilosophicaldefinitionofcomputation.Wethenshowhowtoday>——Give>——Give&shorthistoryofcomputefs.io-ObjectivesAfterstudyingthischapter,thestudentsshouldbeableto:DefinetheTuringmodelofacompute匚DefinethevonNeumannmodelofacomputer.Describethethreecomponentsofacomputer:hardware,data,andsoftware.——Listtopicsrelatedtocomputefhardware.——Listtopicsrelatedtodata.——Listtopicsrelatedtosoftware.2.1.1TURINGMODELTheideaofauniversalcomputationaldevicewasfirstdescribedbyAlanTuringin1937.Heproposedthatallcomputationcouldbeperformedbyaspecialkindofmachine,nowcalledaTuringmachine.AlthoughTuringpresentedamathematicaldescriptionofsuchamachine,hewasmoreinterestedinthephilosophicaldefinitonofcomputationthaninbuildingtheactualmachine.Hebasedthemodelontheactionsthatpeopleperfonnwheninvolvedincomputation.Heabstractedtheseactionsintoamodelforacomputationalmachinethathasreallychangedtheworld.Perceptualknowledge（感性認(rèn)識(shí)）計(jì)算機(jī)組成部分http:〃/~course/cs101/2008/video/comDutercomponents.flvIntroductiontoComputerHardwarehttp:〃/~coursc/csl01/2008/video/intro2computcrhardwarc.flvInstall http:〃net.D/~course/cs101/2008/video/flvplayersetuD.exe,ifyourcomputercannotshowvideos.圖2-1Motherboard（主板：集成多個(gè)部件、適配器，提供它們之間的互聯(lián)）

主板（MainBoard）又名主機(jī)板、系統(tǒng)板、母板，是PC機(jī)的核心部件。PC機(jī)的主板包括CPU、芯片組（Chipset）、高速緩存（Cache）、ROM_BIOS芯片、CMOS芯片、內(nèi)存RAM、總線通道、軟硬磁盤接口、串行和并行接口、USB接口、擴(kuò)展槽（Slots）,直流電源插座、可充電電池以及各種條線。圖中從上到下，左到右：內(nèi)存條，磁盤、光驅(qū)等的數(shù)據(jù)線接口；CPU風(fēng)扇（一般F面是散熱器，和CPU）：棕色AGP槽：只能接顯卡；白色PCI槽：能接顯卡、網(wǎng)卡、聲卡等。圖2-2CPU=運(yùn)算器+控制器圖2-3AlanTuring,founderofcomputerscience,andartificialintelligencehttp:〃/2008/0331/788473.shtml圖靈是舉世罕見的天才數(shù)學(xué)家和計(jì)算機(jī)科學(xué)家，僅僅在世42年。他的英年早逝，像他橫溢的才華?樣，令世界吃驚與難以置信。生命雖然短暫，但那傳奇的人生，豐富多彩的創(chuàng)造力和智慧而深邃的思想，使他猶如一顆耀眼的明星，持續(xù)地照耀著人間后世在科學(xué)的浩瀚太空里探索未來的人們。自上個(gè)世紀(jì)60年代以來,計(jì)算機(jī)技術(shù)飛速發(fā)展，信息產(chǎn)業(yè)逐漸成為影響人類社會(huì)的最重要的工業(yè)之一。支持技術(shù)與工業(yè)發(fā)展的理論基礎(chǔ)是計(jì)算機(jī)科學(xué)。眾所周知，“諾貝爾獎(jiǎng)”是世界上最負(fù)盛名的獎(jiǎng)項(xiàng),但僅用于獎(jiǎng)勵(lì)那些在物理、化學(xué)、文學(xué)、醫(yī)學(xué)、經(jīng)濟(jì)學(xué)與促進(jìn)世界和平等方面做出開拓性重大貢獻(xiàn)的人士。“圖靈獎(jiǎng)”則是計(jì)算機(jī)科學(xué)領(lǐng)域的最高獎(jiǎng)項(xiàng)，有“計(jì)算機(jī)界諾貝爾獎(jiǎng)”之稱。設(shè)立這個(gè)大獎(jiǎng)，既是為了促進(jìn)計(jì)算機(jī)科學(xué)的進(jìn)一步發(fā)展，也是為了紀(jì)念一位天才數(shù)學(xué)家、計(jì)算機(jī)科學(xué)的奠基人艾蘭?圖靈。http:〃/wiki/圖靈圖靈被視為計(jì)算機(jī)科學(xué)之父。1931年進(jìn)入劍橋大學(xué)國王學(xué)院，畢業(yè)后到美國普林斯頓大學(xué)攻讀博士學(xué)位，二戰(zhàn)爆發(fā)后回到劍橋，后曾協(xié)助軍方破解德國的著名密碼系統(tǒng)Enigma,幫助盟軍取得了二戰(zhàn)的勝利。圖靈對(duì)于人工智能的發(fā)展有諸多貢獻(xiàn)，例如圖靈曾寫過一篇名為《機(jī)器會(huì)思考嗎？》(CanMachineThink?)的論文，其中提出了一種用于判定機(jī)器是否具有智能的試驗(yàn)方法，即圖靈試驗(yàn)。至今，每年都有試驗(yàn)的比賽。此外，圖靈提出的著名的圖靈機(jī)模型為現(xiàn)代計(jì)算機(jī)的邏輯工作方式奠定了基礎(chǔ)。http:〃/?course/csl01/2008/video/alanturing.tlvAshortvideodescribingthelifeandunfortunatedeathofAlanTuring.http:〃/wiki/姚期智姚期智，美籍華人，計(jì)算機(jī)科學(xué)家，2000年圖靈獎(jiǎng)得主，是目前唯一一位獲得此獎(jiǎng)項(xiàng)的華人及亞洲人。目前是清華大學(xué)理論計(jì)算機(jī)科學(xué)研究中心教授。因?yàn)閷?duì)計(jì)算理論，包括偽隨機(jī)數(shù)生成，密碼學(xué)與通信復(fù)雜度的諸多貢獻(xiàn)，美國計(jì)算機(jī)協(xié)會(huì)(ACM)決定把該年度的圖靈獎(jiǎng)授予他。DataprocessorsInput Output ? Computer ?Figure1.1AsignlepurposecomputingmachineBeforediscussingtheTuringmodel,letusdefineacomputerasadataprocessor.Usingthisdefinition,acomputeractsablackboxthatacceptsinputdata,processesthedata,andcreatedoutputdata(Figure1.1).Althoughthismodelcandefinethefunctionalityofacomputertoday,itistoogeneral.Inthismodel,apocketcalculatorisalsoacomputer(whichitis,inaliteralsense).Anotherproblemwiththismodelisthatitdoesnotspecifythetypeofprocessing,orwhethermorethanonetypeofprocessingispossible.Inotherwords,itisnotclearhowmanytypesorsetsofoperationsamachinebasedonthismodelcanperform.Isitaspecific-purposemachineorageneral-purposemachine?Thismodelcouldrepresentaspecific-purposecomputer(orprocessor)thatisdesignedtodoasinglejob,suchascontrollingthetemperatureofabuildingorcontrollingthefuelusagesinacar.However,computers,asthetermisusedtoday,aregeneral-purposemahines.Theycandomanydifferenttypesoftasks.ThisimpliesthatweneedtochangethismodelintotheTuringmodeltobeabletoreflecttheactualcomputersoftoday.ProgrammabledataprocessorsTheTuringmodelisabettermodelforageneral-purposecomputer.Thismodeladdsanextraelementtothespecificcomputingmachine:theprogram.Aprogramisasetofinstructionsthattellsthecomputerwhattodowithdata.Figure1.2showstheTuringmodel.IntheTuringmodel,theoutputdatadependsonthecombinationoftwofactors:theinputdataandtheprogram.Withthesameinput,wecangeneratedifferentoutputsifwechangetheprogram.Similarly,withthesameprogram,wecangeneratedifferentoutputsifwechangetheinputdata.Finally,iftheinputdataandtheprogramremainthesame,theoutputshouldbethesame.Letuslookatthreecases.!ProgramOutputinput -Output? ComputerAcomputerbasedontheTuringmodel:programmabledataprocessor

Figure1.3showsthesamesortingprogramwithdifferentinputdata,althoughtheprogramisthesame,theoutputsaredifferent,becausedifferentinputdataisprocessed.Thesameprogram,differentdataFigure1.4showsthesameinputdatawithdifferentprograms.Eachprogrammakesthecomputerperformdifferentoperationsontheinputdata.Thefirstprogramsortsthedata,thesecondaddsthedata,andthethiredfindsthesmallestnumbe匚3,12,8,22Figure1.4Thesameinput,differentprogram3,8,12,223,12,8,22453,12,8,223,12,8,22Figure1.4Thesameinput,differentprogram3,8,12,223,12,8,22453,12,8,22Weexpectthesameresulteachtimeifbothinputdataandtheprogramarethesame,ofcourse.Inotherwords,whenthesameprogramisrunwiththesameinputdata,weexpectthesameoutput.TheuniversalTuringmachineAuniversalTuringmachine,amachinethatcandoanycomputationiftheappropriateprogramisprovided,wasthefirstdescriptionofamodemcomputer.ItcanbeprovedthataverypowerfulcomputerandauniversalTuringmachinecancomputethesamething.Weneedonlyprovidethedataandtheprogram-thedescriptionofhowtodothecomputation—toeithermachine.Infact,auniversalTuringmachineiscapableofcomputinganythingthatiscomputable.Acomputerisamachinethatmanipulatesdataaccordingtoalistofinstructions.VONNEUMANNMODELComputersbuiltontheTuringuniversalmachinestoredataintheirmemory.Around1944-1945,JohnvonNeumannproposedthat,sinceprogramanddataarelogicallythesame,programsshouldalsobestoredinthememoryofacomputer.FoursubsystemsComputersbuiltonthevonNeumannmodeldividethecomputerhardwareintofoursubsystems:memory,arithmeticlogicunit,controlunit,andinput/output(Figure1.5).Memoryisthestoragearea.Thisiswhereprogramsanddataarestoredduringprocessing.Wediscussthereasonsforstoringprogramsanddatalaterinthechapter.Thearithmeticlogicunit(ALU)iswherecalculationandlogicaloperationstakeplace.Foracomputertoactasadataprocessor,itmustbeabletodoarithmeticoperationsondata(suchasaddingalistofnumbers).Itshouldalsobeabletodologicaloperationsondata.Thecontrolunitcontrolstheoperationsofthememory,ALU,andtheinput/outputsubsystmes.Theinputsubsystemacceptsinputdataandtheprogramfromoutsidethecomputer,whiletheoutputsubsystemsendsresultsofprocessingtotheoutsideworld.Thedefinitionoftheinput/outputsubsystemisverybroad:italsoincludessecondarystoragedevicessuchasdiskortapethatstoredataandprogramsforprocessing.Whenadiskstoresdatathatresultsfromprocessing,itisconsideredanoutputdevice;whendataisreadfromthedisk,itisconsideredasainputdevice.ThestoredprogramconceptThevonNeumannmodelstatesthattheprogrammustbestoredinmemory.Thisistotallydifferentfromthearthiteccureofearlycomputersinwhichonlythedatawasstoredinmemory;theprogramsfortheirtasksimplementedbymanipulatingasetofswitchesorbychangingthewiringsystem.Thememoryofmodemcomputershostsbothaprogramanditscorrespondingdata.Thisimpliesthatboththedataandprogramsshouldhavethesameformat,becausetheyarestoredinmemory.Infact,theyarestoredasbinarypatternsinmemory-asequenceofOsandIs.SequentialexecutionofinstructionsAprograminthevonNeumannmodelismadeofafinitenumberofinstructions.Inthismodel,thecontrolunitfetchesoneinstructionfrommemory,decodesit,andthenexecutesit.Inotherwords,theinstructionsareexecutedoneafteranother.Ofcourse,oneinstructionmayrequestthecontrolunittojumptosomepreviousorfollowinginstructions,butthisdoesnotmeanthattheinstructionsarenotexecutedsequentially.SequentialexecutionofaprogramwastheinitialrequirementofacomputerbasedonthevonNeumannmodel.Today'scomputersexecuteprogramsintheorderthatismostefficient.ComputercomponentsWecanthinkofacomputerasbeingmadeupofthreecomponents:computerhardware,data,andcomputersoftware.ComputerhardwareComputerhardwaretodayhasfourcomponentsunderthevonNeumannmodel,althoughwecanhavedifferenttypesofmemory,differenttypesofinput/outputsubsystems,andsoon.DataThevonNeumannmodelclearlydefinesacomputerasadataprocessingmachinethatacceptstheinputdata,processesit,andoutputstheresult.ThevonNeumannmodeldoesnotdefinehowdatamustbestoredinacomputer.Ifacomputerisanelectronicdevice,thebestwaytostoredataisintheformofanelectricalsignal,specificallyitspresenceorabsence.Thisimpliesthatacomputercanstoredatainoneoftwostates.Obviously,thedataweuseindailylifeisnotjustinoneoftwostates.Forexample,ournumberingsystemusesdigitsthatcantakeoneoftenstates(0to9).Wecannot(asyes)storethistypeofinformationinacomputer;itneedstobechangedtoanothersystemthatusesonlytwostates(0and1).Wealsoneedtobeabletoprocessothertypesofdata(text,image,audio,andvideo).Thesealsocannotbestoredinacomputerdirectly,butneedtobechangedtotheappropriateform(OsandIs).加Chapter3,wewillleamhowtestoredifferenttypesofdat?asa-binarypattern,asequence6fOsandIs.InChapter4、weshowhowdataismanipulated,asabinarypattern,insideaccmputer.Althoughdatashouldbestoredinonlyoneforminsideacomputer,abinarypattern,dataoutsideacomputercantakemanyforms.Inaddition,computers(andthenotionofdataprocessing)havecreatedanewfieldofstudyknownasdataorganizaion,whichasksthequestion:canweorganizeourdataintodifferententitiesandformatsbeforestoringitinsideacomputer?Today,dataisnottreatedasaflatsequenceofinformation.Instead,dataisorganizedintosmallunits,smallunitsareorganizedintolargerunits,andsoon.Wewilllookatd@taf?omthispointofviewinChapters11-14.ComputersoftwareComputersoftwareisageneraltermusedtodescribeacollectionofcomputerprograms,proceduresanddocumentationthatperformsometasksonacomputersystem.Thetermincludesapplicationsoftwaresuchaswordprocessorswhichperformproductivetasksforusers,systemsoftwaresuchasoperatingsystems,whichinterfacewithhardwaretoprovidethenecessaryservicesfbrapplicationsoftware,andmiddlewarewhichcontrolsandco-ordinatesdistributedsystems.Softwareincludeswebsites,programs,videogamesetc.thatarecodedbyprogramminglanguageslikeC,C++,etc.HistoryInthissectionwebrieflyreviewthehistoryofcomputingandcomputers.Wedividethishistoryintothreeperiods.Mechanicalmachines(before1930)機(jī)械計(jì)算機(jī)器Duringthisperiod,severalcomputingmachineswereinventedthatbearlittleresemblancetothemodemconceptofacomputer.圖2-2齒輪加法器1645年，法國Pascal發(fā)明了齒輪式加減法器.Inthe17thcentury,BlaisePascal,aFrenchmathematicianandphilosopher,inventedPascaline.1673年，德國數(shù)學(xué)家Leibniz發(fā)明了乘除器.Inthelate17thcentury,aGermanmathematiciancalledGottfriedLeibnitzinventedwhatisknownasLeibnitz9Wheel.ThefirstmachinethatusedtheideaofstorageandprogrammingwastheJacquardloom,inventedbyJoseph-MarieJacquardatthebeginningofthe19thcentury.第一臺(tái)現(xiàn)代意義的計(jì)算機(jī)1821年，英國數(shù)學(xué)家C.Babbage設(shè)計(jì)了差分機(jī)，這是第一臺(tái)可自動(dòng)進(jìn)行數(shù)學(xué)變換的機(jī)器，由于條件所限沒有實(shí)現(xiàn)。他被譽(yù)為“計(jì)算機(jī)之父。In1823,CharlesBabbageinventedtheDifferenceEngine.Later,heinventedamachinecalledtheAnalyticalEnginethatparallelstheideaofmodemcomputers.圖2?3國數(shù)學(xué)家C.Babbage設(shè)計(jì)了差分機(jī)In1890,HermanHollerith,workingattheUSCensusBureau,designedandbuiltaprogrammermachinethatcouldautomaticallyread,tally,andsortdatastoredonpunchedcards.Thebirthofelectroniccomputers(1930-1950)電子計(jì)算機(jī)的誕生Between1930and1950,severalcomputerswereinventedbyscientistswhocouldbeconsideredthepioneersoftheelectroniccomputerindustry.Theearlyelectroniccomputersofthisperioddidnotstoretheprograminmemory-allwereprogrammedexternally.Fivecomputerswereprominentduringtheseyears:ABC,Zl,MarkI,Colossus,andENIAC.

現(xiàn)代第一臺(tái)通用的大型電子數(shù)字計(jì)算機(jī)1945年，ENIAC(ElectronicNumericalIntegratorandComputer)在賓夕法尼亞大學(xué)誕生。ENIAC用了近18000個(gè)真空管，重達(dá)30噸，耗電150千瓦，長(zhǎng)30米，寬1米，高2.4米，每秒5000次加法運(yùn)算。圖24ENIACComputersbasedonthevonNeumannmodelThefirstcomputerbasedonvonNeumann'sideaswasmadein1950attheUniversityofPennsylvaniaandwascalledEDVAC.Atthesametime,asimilarcomputercalledEDSACwasbuiltbyMauriceWilkesatCambridgeUniversityinEngland.邁向現(xiàn)代計(jì)算機(jī)AlanTuring(1912-1954)1936年上研究生時(shí)提出了圖靈機(jī)(TuringMachine),奠定了計(jì)算機(jī)的理論基礎(chǔ)。ACMTuringAward:the“NobelPrizeofcomputing^^JohnvonNeumann。903/957)1946年發(fā)表了一篇關(guān)于如何用數(shù)字來表示邏輯操作的論文，vonNeumann體系結(jié)構(gòu)為現(xiàn)代計(jì)算機(jī)普遍采用。Computergenerations(1950-present)計(jì)算機(jī)的誕生Computersbuiltafter1950moreorlessfollowthevonNeumannmod