大学计算机基础课程总结英文

Summary考试安排时间12月20日，周日上午，90分钟课程答疑12月16日（周三）晚11-12节；地点：1-106平时作业所有作业+实验报告必须在12月20日前全部在在线教室提交考试安排考题类型Termmatching（5题10分）Multiplechoice（10题20分）Completion（10题10分）Computation（2题12分）Flowchart（1题8分）OutlineComputerSystemHardwareSoftwareDatarepresentationincomputerNetworkAlgorithmdesignDatabaseSecurityDefinitionAcomputerisanelectronicdevicewhich•operatesunderthecontrolofstoredinstructions•acceptsdatainput•processesthedataaccordingtospecifiedrules•producesandstoresoutputInputOutputProgramComputerWhat’scomputer5Acomputer’spowerisderivedfromSpeedReliabilityAccuracyStorageCommunicationsWhat’scomputer6HardwareVonNeumannmachineFoundationofmoderncomputersUsebinaryinformationTheprincipleofstoredprogramTwostepsofamachinecycle:InstructioncycleandexecutioncycleFivebasiccomponentsControlUnitArithmetic/logicUnit(ALU)InputdevicesOutputdevicesStorage–primaryandsecondarystorageHardwareSystemUnit(主机)MotherboardProcessor–CPUALUControlUnitMemoryRAM,ROM,CMOS,CacheAlldataandinstructionsmustbeloadedintoRAMbeforetheycanbeexecutedBus–datahighwaybetweendevicesExpansionslots/cards(扩展槽/卡)toaddextradevicesvideocard,soundcard,networkcardPort(端口)–aplugforacablethatleadstoadeviceusbports,RJ-45,VGAportformonitorHardwareCPUperformanceClockratefrequencyfordatatransportandinstructionexecutionWordsizenumberofbitstheCPUcanmanipulateatonetimeCacheCacheisspecialhigh-speedmemorythatgivestheCPUmorerapidaccesstodataInstructionsetsizeHardwareSecondaryStorageSlowerCommunicatewithmemory(RAM)Nonvolatile,permanentstorageCheapIncludes:FloppydiskHarddiskTapeOpticaldisk–CD/DVDFlashdiskDifferencebetweenthesesecondarystorageSoftwareSoftwareCategoriesSystemsoftwareTomanageacomputersystematafundamentallevelConsistsoftheprogramsthatcontroltheoperationsofthecomputeranditsdevices•Operatingsystem•UtilityprogramApplicationsoftwareTosolveproblemsintherealworldSoftwareOperatingsystemPrograms/Softwaremanagecomputerresources,•Memorymanagement•Processmanagement•CPUschedulingprovideaninterfacebetweenusersandthecomputer,•command-lineinterface•graphicaluserinterface(GUI)allowanapplicationprogramtointeractwithothersystemresources•Singleuser&Multiuser•Multitasking•MultiprocessingSoftwareFileSystemsandDirectoriesDescribethepurposeoffiles,filesystems,anddirectoriesFile:anamedcollectionofrelateddataFilesystem:theoperatingsystem'slogicalviewofthefilesitmanagesDirectory:anamedgroupoffilesDistinguishbetweentextandbinaryfilesAllfilesareinfactstoredinbinary,butbeinginterpretedindifferentwaysTextfile:afileinwhichthebytesofdataareorganizedascharactersfromtheASCIIorUnicodecharactersetsBinaryfile:afilethatcontainsdatainaspecificformat,requiringinterpretationIdentifyvariousfiletypesbytheirextensions.txtfortextfiles.exeforexecutableprogramsSoftwareFileSystemsandDirectoriesDirectorytree–nestedorganizationofafilesystemRootdirectory,e.g.C:\orD:\inwindowsSubdirectoriesorfoldersCompareabsoluteandrelativepathsPath:Atextdesignationofthelocationofafileorsubdirectoryinafilesystem,consistingoftheseriesofdirectoriesthroughwhichyoumustgotofindthefileAbsolutepath:ApaththatbeginsattherootandspecifieseachstepdownthetreeuntilitreachesthedesiredfileordirectoryRelativepath:ApathnamethatbeginsatthecurrentworkingdirectoryDataandComputersComputersaremultimediadevices,dealingwithmanycategoriesofinformation.Computersstore,present,andhelpmodify:NumbersTextAudioImagesandgraphicsVideo15Binarycomputershavestorageunitscalledbinarydigitsorbitsbit:ThesmallestelementEitherbe0(LowVoltage)or1(HighVoltage)Byte:Thesmalleststorageunit1Byte=8bitsStorageunit(B,KB,MB,GB,TB):1KB=210B=1024B；1MB=220B=1024KB=10242B；1GB=230B=1024MB=10242KB=10243B；1TB=240B=1024GB=10242MBComputerStorage16NumberSystemDecimalconsistsof10digits0，1，2，3，4，5，6，7，8，9Base10Binaryconsistsof2digits0，1Base2Octalconsistsof8digits0，1，2，3，4，5，6，7Base8Hexadecimalconsistsof16digits0，1，2，3，4，5，6，7，8，9，A,B,C,D,E,FBase16DatarepresentationE.g..(100)10,100DE.g..(100)2,100BE.g..(100)16,100HThreecategoriesNon-DecimaltoDecimal•SpreadnumberbypowerDecimaltoNon-Decimal•Decimalinteger:numberisdividedbyR,theremaindersarrangedinreverseorder.•Decimalfraction:multiplybaseR，arrangetheintegerpartinorder.Non-DecimaltoNon-Decimal•Conversiontable,groupofthree/fourbitsDatarepresentationNumberConversionS=KiRiKi{0,1,……,R-1}ni=-mInteger:fromrighttolefti=0,1,2,3……Decimalfraction:fromlefttorighti=-1,-2,-3…...DatarepresentationCodeofnumericaldatanbitscanrepresent2nthingsforbinarydata;otherwise,overflowoccursRealvalue:thedecimalvalueofamachinenumberMachinenumber:CodeofnumberandthesignTiptopdigitofbinarynumbershowthesign;0for“+”,1for“-”OriginalcodeandComplementcode,todosubtractioninadditionComplement=Modulus+Original,ORForpositivenumber：complement=originalFornegativenumber:•Original:signbitis1,therestisitsabsolutevalue•Complement:reversealldigitsexceptthesign,theplus1Complementofcomplement=originalComputationiscarriedoutintheformofComplementcodeDatarepresentationCodeofcharacte