资源描述
Unit 121-1 What Is Computer Science?1-1 What Is Computer Science?1-2 Von Neumann Model1-2 Von Neumann Model1-3 Computer Components1-3 Computer Components1-4 History and Development Trends1-4 History and Development Trends1-5 Frontiers of Computer Technology1-5 Frontiers of Computer Technology1-6 Major Fields of Computer Science1-6 Major Fields of Computer Science1-7 References and Recommended Readings1-7 References and Recommended Readings1-8 Key terms1-8 Key terms1-9 Summary1-9 Summary1-10 Practice Set1-10 Practice SetOUTLINE21-1 What Is Computer Science?3UnderstandUnderstandthedefinitionofcomputerscience.thedefinitionofcomputerscience.UnderstandUnderstandthedevelopmentandthefrontiersthedevelopmentandthefrontiersofcomputerofcomputertechnology.technology.After reading this chapter,you are supposed tobe able to:OBJECTIVESMasterMasterthevonNeumannarchitecture.thevonNeumannarchitecture.Understandthreeimportantcomponentsofacomputer:Understandthreeimportantcomponentsofacomputer:computerhardware,computersoftware,puterhardware,computersoftware,anddata.UnderstandUnderstandthehistoryofcomputers.thehistoryofcomputers.UnderstandUnderstandthemajorfieldsofcomputerscience.hemajorfieldsofcomputerscience.3Understand the definition of 41-1 What Is Computer Science?ComputerscienceisadisciplinethatinvolvesComputerscienceisadisciplinethatinvolvesthetheoreticalthetheoreticalfoundationsofcomputationandtheirapplicationsfoundationsofcomputationandtheirapplicationsincomputerincomputersystems.systems.ItisdifficulttolistacompleterangeofcomputerresearchareasItisdifficulttolistacompleterangeofcomputerresearchareasduetotheirrapidpaceofinnovation.Thisdisciplinecontainsduetotheirrapidpaceofinnovation.Thisdisciplinecontainsmanysub-fieldsmanysub-fields,suchas:,suchas:n ndatabasesystemsdatabasesystemsn nartificialintelligenceartificialintelligencen ncomputerarchitecturecomputerarchitecturen ncomputernetworkingandcomputernetworkingandcommunicationcommunicationn nparallelcomputationparallelcomputationn nn nprogrammingmethodologyprogrammingmethodologyandlanguagesandlanguagesn nalgorithmanddatastructurealgorithmanddatastructuren ncomputationalcomplexitycomputationalcomplexitytheorytheoryn ncomputergraphicscomputergraphicsn noperatingsystemsoperatingsystemsn nsoftwareengineeringsoftwareengineering41-1 What Is Computer Science?51-1 What Is Computer Science?ComputerscienceisarelativelyyoungdisciplinethatComputerscienceisarelativelyyoungdisciplinethatbeginsinthe1940s.Itspanstheoryandpractice.Itbeginsinthe1940s.Itspanstheoryandpractice.Itcanbeseenascanbeseenasascienceofproblemsolvingascienceofproblemsolving.IthasIthasstrongassociationswithotherdisciplinesstrongassociationswithotherdisciplines.Many.Manyproblemsinengineering,science,medicine,problemsinengineering,science,medicine,agriculture,business,andotherfieldscanbesolvedagriculture,business,andotherfieldscanbesolvedeffectivelywithcomputers.Theeffectivelywithcomputers.Thecross-disciplinarycross-disciplinaryknowledgeknowledgeisnecessaryinordertofindasolution.isnecessaryinordertofindasolution.51-1 What Is Computer Science?6TheThevonNeumannmodelvonNeumannmodel【冯冯冯冯 诺依曼模型诺依曼模型诺依曼模型诺依曼模型】isadesignarchitectureforisadesignarchitectureforanelectronicdigitalcomputer.Itconsistsofananelectronicdigitalcomputer.Itconsistsofanarithmeticlogicunitarithmeticlogicunit【算算算算术逻辑单元术逻辑单元术逻辑单元术逻辑单元】,a,acontrolunitcontrolunit【控制器控制器控制器控制器】,a,amemorymemory【内存内存内存内存】,an,anexternalexternalstoragestorage【外部存储器外部存储器外部存储器外部存储器】,and,andinputinput【输入输入输入输入】andandoutputoutput【输出输出输出输出】mechanisms(mechanisms(Figure1.1Figure1.1).).1-2VonNeumannModel6The von Neumann model【冯【冯诺依曼模诺依曼模7ComputersbasedontheComputersbasedontheTuringmachineTuringmachine【图灵机图灵机图灵机图灵机】storestoredatadata【数据数据数据数据】intheirmemoryintheirmemory.Around19441945,Johnvon.Around19441945,JohnvonNeumannproposedthatNeumannproposedthatprogramsprograms【程序程序程序程序】shouldalsobeshouldalsobestoredinthememorystoredinthememory.BothdataandprogramsinthevonNeumannmodelhavetheBothdataandprogramsinthevonNeumannmodelhavethesamelogicalformat.Theyarestoredassamelogicalformat.Theyarestoredasbinarybinary【二进制二进制二进制二进制】patternsinmemoryasequenceof0sand1s.Aprograminpatternsinmemoryasequenceof0sand1s.AprograminthevonNeumannmodelcontainsafinitenumberofthevonNeumannmodelcontainsafinitenumberofinstructionsinstructions【指令指令指令指令】thatarethatareexecutedsequentiallyexecutedsequentially【按顺按顺按顺按顺序执行序执行序执行序执行】.1-2VonNeumannModel7Computers based on the Turin8ThebusThebus【总线总线总线总线】issharedisshared【共享共享共享共享】betweentheprogrambetweentheprogrammemoryanddatamemory,leadingtothevonNeumannmemoryanddatamemory,leadingtothevonNeumannbottleneckbottleneck【瓶颈瓶颈瓶颈瓶颈】.Ithasoftenbeenconsideredanissue.Ithasoftenbeenconsideredanissueduetothelimitedduetothelimitedthroughputthroughput【吞吐量吞吐量吞吐量吞吐量】betweenthebetweenthecentralprocessingunit(CPU)centralprocessingunit(CPU)【中央处理单元（器）中央处理单元（器）中央处理单元（器）中央处理单元（器）】andandmemory,becauseofthesinglebusthatcanonlyaccessoneofmemory,becauseofthesinglebusthatcanonlyaccessoneofthetwoclassesofmemoryatatime.thetwoclassesofmemoryatatime.WhentheCPUisrequiredtoexecuteminimalprocessingonWhentheCPUisrequiredtoexecuteminimalprocessingonlargeamountsofdata,itisforcedtolargeamountsofdata,itisforcedtowaitforneededdatatowaitforneededdatatobetransferredbetransferredtoorfrommemory,whichseriouslytoorfrommemory,whichseriouslylimitsthelimitstheprocessingspeedprocessingspeed.1-2VonNeumannModel8 The bus【总线】【总线】is shared【共享【共享9n nAcomputingsystemconsistsofAcomputingsystemconsistsofhardwarehardware【硬件【硬件【硬件【硬件】,softwaresoftware【软件】【软件】【软件】【软件】,and,anddatadata【数据】【数据】【数据】【数据】.vvComputerhardwareisthecollectionofphysicalpartsComputerhardwareisthecollectionofphysicalparts ofacomputer,suchasamonitorofacomputer,suchasamonitor【显示器】【显示器】【显示器】【显示器】,agraphic,agraphiccardcard【显卡】【显卡】【显卡】【显卡】,aharddiskdrive(HDD),aharddiskdrive(HDD)【硬盘驱动器【硬盘驱动器【硬盘驱动器【硬盘驱动器】,asoundcard,asoundcard【声卡】【声卡】【声卡】【声卡】,memory,amotherboard,memory,amotherboard【主板】主板】主板】主板】,amouse,amouse【鼠标】【鼠标】【鼠标】【鼠标】,akeyboard,akeyboard【键盘】【键盘】【键盘】【键盘】,and,andsoon.soon.vvComputersoftwareisacollectionofcomputerComputersoftwareisacollectionofcomputerprograms,programs,say,operationsystems,say,operationsystems,procedures,andprocedures,anddocumentationdocumentation.vvDataDataarearethedistinctinformationwithwhichathedistinctinformationwithwhichacomputersystemdealscomputersystemdeals.1-3ComputerComponents9A computing system consists o10n nComputerhardwarereferstothecomponentsthatyouComputerhardwarereferstothecomponentsthatyoucancan physicallytouchphysicallytouch.Therearemanypartsofcomputer.Therearemanypartsofcomputerhardwarethatcanbeinstalledinside,orconnectedtothehardwarethatcanbeinstalledinside,orconnectedtotheoutside,ofacomputer.outside,ofacomputer.vvTheTheexternalhardwareexternalhardwareincludesaflat-panelincludesaflat-panel【平板显示器】【平板显示器】【平板显示器】【平板显示器】,aprinteraprinter【打印机】【打印机】【打印机】【打印机】,aprojector,aprojector【投影仪】【投影仪】【投影仪】【投影仪】,ascanner,ascanner【扫描仪】扫描仪】扫描仪】扫描仪】,aspeaker,aspeaker【扬声器】【扬声器】【扬声器】【扬声器】,akeyboard,amouse,a,akeyboard,amouse,aflashmemoryflashmemory【闪存】【闪存】【闪存】【闪存】,andsoon.,andsoon.vvTheTheinternalhardwareinternalhardwareincludesCPU,amulti-coreprocessorincludesCPU,amulti-coreprocessor【多核处理器】【多核处理器】【多核处理器】【多核处理器】,amotherboard,anetworkcard,amotherboard,anetworkcard【网卡】【网卡】【网卡】【网卡】,amodemamodem【调制解调器】【调制解调器】【调制解调器】【调制解调器】,asoundcard,avideocard,asoundcard,avideocard【显【显【显【显卡】卡】卡】卡】,adrive(e.g.Blue-Ray,adrive(e.g.Blue-Ray【蓝光】【蓝光】【蓝光】【蓝光】,CD-ROM,CD-ROM【只读光【只读光【只读光【只读光盘驱动器】盘驱动器】盘驱动器】盘驱动器】,DVD,DVD【数字通用光盘】【数字通用光盘】【数字通用光盘】【数字通用光盘】,floppydrive,floppydrive【软盘【软盘【软盘【软盘驱动器】驱动器】驱动器】驱动器】,harddiskdrive(HDD),harddiskdrive(HDD)【硬盘驱动器】【硬盘驱动器】【硬盘驱动器】【硬盘驱动器】),asolid-),asolid-statedisk(SSD)statedisk(SSD)【固态硬盘】【固态硬盘】【固态硬盘】【固态硬盘】,andsoon.,andsoon.Computerhardware10Computer hardware refers to 11n nComputersoftwareisComputersoftwareisa a collectioncollectionofprogramsthatacomputerofprogramsthatacomputerexecutesexecutes【执行】【执行】【执行】【执行】.Theprogramconsistsofasequenceofinstructions.Theprogramconsistsofasequenceofinstructions.Eachinstructionoperatesononeormoredataitems.TheseEachinstructionoperatesononeormoredataitems.Theseinstructionsmightbeinstructionsmightbeasetofasetofinternalinternalsystemcommandssystemcommands【系统命令】【系统命令】【系统命令】【系统命令】,orresponsestoorresponsestothetheexternalinputexternalinputorrequestorrequest.Software.Softwaretellstellsvariousvarioushardwarecomponentswhattodoandhowtointeractwitheachother.hardwarecomponentswhattodoandhowtointeractwitheachother.n nTherearetwomaintypesofsoftwareTherearetwomaintypesofsoftwaresetssets:systemsoftwaresystemsoftware【系统软件【系统软件【系统软件【系统软件】andandapplicationsoftwareapplicationsoftware【应用软件】【应用软件】【应用软件】【应用软件】.Systemsoftwareisusedto.Systemsoftwareisusedtorunhardware,whileapplicationsoftwareisusedtorunhardware,whileapplicationsoftwareisusedtocarryoutcarryoutotherothertasks.Themainsystemsoftwareincludestasks.Themainsystemsoftwareincludesoperatingsystemsoperatingsystems【操作系【操作系【操作系【操作系统】统】统】统】andanddriversdrivers【驱动程序】【驱动程序】【驱动程序】【驱动程序】.Themainapplicationsoftware.Themainapplicationsoftwareincludesgames,mediaplayers,wordprocessors,includesgames,mediaplayers,wordprocessors,anti-virusprogramsanti-virusprograms【杀毒软件】【杀毒软件】【杀毒软件】【杀毒软件】,andsoon.Softwareisusuallywrittenin,andsoon.Softwareisusuallywritteninhigh-levelhigh-levelprogramminglanguagesprogramminglanguages【高级编程语言】【高级编程语言】【高级编程语言】【高级编程语言】,whicharetranslatedinto,whicharetranslatedintothethemachinelanguagemachinelanguage【机器语言】【机器语言】【机器语言】【机器语言】byabyacompilercompiler【编译器】【编译器】【编译器】【编译器】oranoraninterpreterinterpreter【解释器】【解释器】【解释器】【解释器】.Softwaremayalsobewritteninalow-level.Softwaremayalsobewritteninalow-levelassemblylanguageassemblylanguage【汇编语言】【汇编语言】【汇编语言】【汇编语言】insomededicatedscenariosinsomededicatedscenarios.Computersoftware11Computer software is a colle12n nDataDatacouldbecouldbeanysequenceofsymbolsanysequenceofsymbolshavinghavinggivenmeaningbygivenmeaningbyspecificactionsofinterpretationspecificactionsofinterpretation【解释】【解释】【解释】【解释】.Indailylife,we.Indailylife,weusuallyusedigitsthatcantakeoneoftenstates(0to9).However,usuallyusedigitsthatcantakeoneoftenstates(0to9).However,datastoredinacomputergenerallyuseonlytwostates(0and1).datastoredinacomputergenerallyuseonlytwostates(0and1).Someformsofdata(text,image,audio,andvideo)cannotbeSomeformsofdata(text,image,audio,andvideo)cannotbestoredinacomputerdirectly,andneedstobeconvertedintothestoredinacomputerdirectly,andneedstobeconvertedintothebinarybinary【二进制】【二进制】【二进制】【二进制】form(0sand1s).form(0sand1s).n nDatacanbeorganizedinmanytypesofDatacanbeorganizedinmanytypesofdatastructuresdatastructures【数据结【数据结【数据结【数据结构】构】构】构】,suchassuchas arraysarrays【数组】【数组】【数组】【数组】,listslists【列表】【列表】【列表】【列表】,graphsgraphs【图】【图】【图】【图】,andandobjectsobjects【对象】【对象】【对象】【对象】.Modernhighperformance.Modernhighperformancedatapersistencedatapersistence【数据持久性】【数据持久性】【数据持久性】【数据持久性】technologiesrelyonmassivelytechnologiesrelyonmassivelyparallelparalleldistributeddataprocessingdistributeddataprocessing【并行分布式数据处理】【并行分布式数据处理】【并行分布式数据处理】【并行分布式数据处理】,suchas,suchasApacheHadoopApacheHadoop.Insuchsystems,thedata.Insuchsystems,thedataarearedistributedacrossdistributedacrossmultiplecomputersandcanbeprocessedondifferentcomputersmultiplecomputersandcanbeprocessedondifferentcomputersatthesametime.atthesametime.Data12Data could be any sequence o13n nComputersciencehasundergonearapiddevelopmentComputersciencehasundergonearapiddevelopmentsinceitsbirth.Asthefieldofcomputersciencehassinceitsbirth.Asthefieldofcomputersciencehasemerged,newdirectionsofresearchandapplicationshaveemerged,newdirectionsofresearchandapplicationshavecreatedandcombinedwithclassicaldiscoveriesinacreatedandcombinedwithclassicaldiscoveriesinacontinuouscycleofgrowthandrevitalization.continuouscycleofgrowthandrevitalization.n nLifewithoutacomputerisunimaginable.ThehistoryofLifewithoutacomputerisunimaginable.Thehistoryofcomputerisanattractivestory.Computerswerenotcomputerisanattractivestory.Computerswerenotalwaysthebrilliantfastmachinesempoweringustoobtainalwaysthebrilliantfastmachinesempoweringustoobtainlotsofknowledge.Actually,thefirstcomputerwasverylotsofknowledge.Actually,thefirstcomputerwasverydifferentfromtherecentcomputers.Generallyspeaking,differentfromtherecentcomputers.Generallyspeaking,thehistoryofcomputerscanbedividedintothreeperiodsthehistoryofcomputerscanbedividedintothreeperiods.1-4HistoryandDevelopmentTrends13Computer science has undergo14(1)Mechanicalmachines(1)MechanicalmachinesvvIntheearly17thcentury,aFrenchmathematiciancalledIntheearly17thcentury,aFrenchmathematiciancalledBlaisePascalinventedPascaline,whichisaBlaisePascalinventedPascaline,whichisamechanicalmechanicalcalculatorcalculator【机械计算器】【机械计算器】【机械计算器】【机械计算器】performingperformingadditionaddition【加法】【加法】【加法】【加法】andandsubtractionsubtraction【减法】【减法】【减法】【减法】.vvInthelate17thcentury,GottfriedLeibnitz,aGermanInthelate17thcentury,GottfriedLeibnitz,aGermanmathematician,inventedLeibnitzWheel.mathematician,inventedLeibnitzWheel.vvIntheearly19thcentury,Joseph-MarieJacquardinventedIntheearly19thcentury,Joseph-MarieJacquardinventedJacquardloom,whichadoptedtheideaofstorageandJacquardloom,whichadoptedtheideaofstorageandprogrammingatthefirsttime.programmingatthefirsttime.vvInthe1820s,CharlesBabbageinventedAnalyticalEngine.Inthe1820s,CharlesBabbageinventedAnalyticalEngine.vvIn1890,HermanHollerithinventedaprogrammableIn1890,HermanHollerithinventedaprogrammablemachinethatcouldreadandsortdataonpunchedcardsmachinethatcouldreadandsortdataonpunchedcardsautomatically.automatically.Computerhistory14(1)Mechanical machinesComp15(2)Electroniccomputers(2)ElectroniccomputersvvBetween1930and1950,severalscientistscontributedintheBetween1930and1950,severalscientistscontributedintheevolutionofcomputertechnologywhocouldbeconsideredthetrueevolutionofcomputertechnologywhocouldbeconsideredthetrueearlypioneersofcomputerscience.earlypioneersofcomputerscience.vvJohnVincentAtanasoffandhisassistantCliffordBerryinventedJohnVincentAtanasoffandhisassistantCliffordBerryinventedtheABC(AtanasoffBerryComputer)tosolveasystemoflineartheABC(AtanasoffBerryComputer)tosolveasystemoflinearequations.Itencodedinformationelectrically.equations.Itencodedinformationelectrically.vvInthe1930s,ahugecomputercalledMarkI,wasbuiltundertheInthe1930s,ahugecomputercalledMarkI,wasbuiltunderthedirectionofHowardAikenatHarvardUniversity.InEngland,directionofHowardAikenatHarvardUniversity.InEngland,AlanTuringinventedacomputercalledColossustobreaktheAlanTuringinventedacomputercalledColossustobreaktheGermanEnigmacode.GermanEnigmacode.vvIn1946,JohnMauchlyandJ.PresperEckertinventedENIACIn1946,JohnMauchlyandJ.PresperEckertinventedENIAC(ElectronicNumericalIntegratorandCalculator),thefirsttotally(ElectronicNumericalIntegratorandCalculator),thefirsttotallyelectroniccomputerelectroniccomputer【电子计算机】【电子计算机】【电子计算机】【电子计算机】.vvIn1950,In1950,EDVACEDVAC,thefirstcomputertoimplementthe,thefirstcomputertoimplementthestoredstoredprogramprogramconceptconceptbasedonvonNeumannbasedonvonNeumann sideassideaswasbuiltatthewasbuiltattheUniversityofPennsylvania.UniversityofPennsylvania.Computerhistory15(2)Electronic computersCom16(3)Computersafter1950(3)Computersafter1950vvBetween1950and1959,computerswerebulkyandutilizedBetween1950and1959,computerswerebulkyandutilizedvacuumtubesvacuumtubes【电子管】【电子管】【电子管】【电子管】aselectronicswitches.aselectronicswitches.vvBetween1959and1965,Between1959and1965,transistorstransistors【晶体管】【晶体管】【晶体管】【晶体管】replacedreplacedvacuumtubes.Thenthesizeandthecostofthevacuumtubes.Thenthesizeandthecostofthetransistorizedcomputersweredramaticallyreduced.transistorizedcomputersweredramaticallyreduced.vvFrom1965to1975,theappearanceoftheFrom1965to1975,theappearanceoftheintegratedcircuitintegratedcircuit(IC)(IC)【集成电路】【集成电路】【集成电路】【集成电路】puters.vvBetween1975and1985,microcomputersappeared.TheBetween1975and1985,microcomputersappeared.TheAltair8800,thefirstAltair8800,thefirstdesktopcalculatordesktopcalculator【台式计算机】【台式计算机】【台式计算机】【台式计算机】,wasinventedin1975.wasinventedin1975.Computerhistory16(3)Computers after 1950Com17(3)Computersafter1950(3)Computersafter1950vvBetween1985and1995,someadvancedcomputerBetween1985and1995,someadvancedcomputertechnologyappeared,suchastechnologyappeared,suchasClustersClusters【集群】【集群】【集群】【集群】,VectorVectorProcessorsProcessors【向量处理器】【向量处理器】【向量处理器】【向量处理器】,workstationsworkstations【工作站】【工作站】【工作站】【工作站】,minicomputersminicomputers【小型计算机】【小型计算机】【小型计算机】【小型计算机】,laptopslaptops【笔记本电脑】【笔记本电脑】【笔记本电脑】【笔记本电脑】andandpalmtopcomputerspalmtopcomputers【掌上电脑】【掌上电脑】【掌上电脑】【掌上电脑】,andsoon.,andsoon.vvAfter1995,After1995,high-performancecomputers(HPC)high-performancecomputers(HPC)【高性能计【高性能计【高性能计【高性能计算机】算机】算机】算机】obtainedagreatadvancement,suchasobtainedagreatadvancement,suchassupercomputerssupercomputers【超级计算机】【超级计算机】【超级计算机】【超级计算机】,many-coresmany-cores【多核】【多核】【多核】【多核】personalcomputerspersonalcomputers【个人电脑】【个人电脑】【个人电脑】【个人电脑】,general-purposegeneral-purposegraphicsprocessingunit(GPGPU)graphicsprocessingunit(GPGPU)【通用计算图形处理单元【通用计算图形处理单元【通用计算图形处理单元【通用计算图形处理单元（器）】（器）】（器）】（器）】,andsoon.,andsoon.Computerhistory17(3)Computers after 1950Com18n nInthefuture,computertechnologywillbecharacterizedInthefuture,computertechnologywillbecharacterizedbyhighperformance,miniaturization,network,byhighperformance,miniaturization,network,popularization,intelligence,andhumanization.popularization,intelligence,andhumanization.vv(1)Lightweightmicrocomputer(1)Lightweightmicrocomputer ThelightweightmicrocomputerThelightweightmicrocomputer【轻量级轻量级轻量级轻量级微型计算机微型计算机微型计算机微型计算机】withsmallsize,lowprice,powerfulfunction,andwithsmallsize,lowprice,powerfulfunction,andhighreliabilitywillbepopular.highreliabilitywillbepopular.vv(2)Highperformancecomputer(2)HighperformancecomputerDevelopmentofpowerfulsupercomputerswithhighDevelopmentofpowerfulsupercomputerswithhighspeed,highperformance,andcapabilityofspeed,highperformance,andcapabilityofprocessinglargeandcomplexproblemsisalsotheprocessinglargeandcomplexproblemsisalsothedefinitetrend.definitetrend.Developmenttrends18In the future,computer tech19(1)Lightweightmicrocomputer(1)LightweightmicrocomputervvAAPocketPCPocketPC【掌上电脑】【掌上电脑】【掌上电脑】【掌上电脑】isaisahandhelddevicehandhelddevice【手持【手持【手持【手持设备】设备】设备】设备】thatcanbeusedtoprocesse-mail,playgames,thatcanbeusedtoprocesse-mail,playgames,exchangemessages,browsetheWeb,andsoon.exchangemessages,browsetheWeb,andsoon.vvAAlaptopcomputerlaptopcomputer【笔记本电脑】【笔记本电脑】【笔记本电脑】【笔记本电脑】hasmostofthehasmostofthesamecomponentsintoasingleunitasadesktopsamecomponentsintoasingleunitasadesktopcomputer,suchasakeyboard,apointingdevice,acomputer,suchasakeyboard,apointingdevice,adisplay,andspeakers.Laptopcomputershavebecomedisplay,andspeakers.Laptopcomputershavebecomeincreasinglypopularbecausetheyarebecomingincreasinglypopularbecausetheyarebecomingsmaller,lighter,cheaper,andmorepowerful,andtheirsmaller,lighter,cheaper,andmorepowerful,andtheirscreensarebecomingsmallerandofbetterquality.screensarebecomingsmallerandofbetterquality.Developmenttrends19(1)Lightweight microcomput20(1)Lightweightmicrocomputer(1)LightweightmicrocomputervvAAsmartphonesmartphone【智能手机】【智能手机】【智能手机】【智能手机】isbasedonamobileoperatingisbasedonamobileoperatingsystemsystemsuchasAndroidsuchasAndroid【安卓安卓安卓安卓】oriOSoriOS.Theearlysmart.Theearlysmartphonesaddedthefunctionsofaphonesaddedthefunctionsofapersonaldigitalassistantpersonaldigitalassistant(PDA)(PDA)【个人数字助理】【个人数字助理】【个人数字助理】【个人数字助理】,aportablemediaplayer,alow-,aportablemediaplayer,alow-endcompactdigitalcamera,andapocketvideocamera.endcompactdigitalcamera,andapocketvideocamera.Manymodernsmartphonesalsocontainhigh-resolutionManymodernsmartphonesalsocontainhigh-resolutiontouchscreenstouchscreens【触摸屏】【触摸屏】【触摸屏】【触摸屏】,webbrowsers,webbrowsers,globalpositioningglobalpositioningsystem(GPS)system(GPS)【全球定位系统】【全球定位系统】【全球定位系统】【全球定位系统】navigationnavigation【导航】【导航】【导航】【导航】units,units,andsoon.andsoon.vvAniPadisakindofAniPadisakindoftabletcomputerstabletcomputers【平板电脑】【平板电脑】【平板电脑】【平板电脑】builtonbuiltonApplesiOSoperatingsystem.ApplesiOSoperatingsystem.IthasmanyIthasmanyfunctionsfunctionssuchassuchasvideoplayer,camera,musicplayer,webbrowser,emaivideoplayer,camera,musicplayer,webbrowser,email
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