计算机应用基础(双语)课件PPTChax 55页

'Chapter1ComputerHardware1 What’sinside?Inthischapter,youwill:GainanoverviewofcomputerequipmentandterminologyLearnhowcomputersareclassifiedLearnhowpersonalcomputersfitintothegamutofmachinesfromPDAstosupercomputersReviewbasiccomponentsofatypicalpersonalcomputersystemLookinsidethesystemunitExploreadvantagesanddisadvantagesofseveralcomputerstoragedevicesLearnsomebasicsaboutmaintainingyourcomputerandtroubleshootingproblems2PracticalComputerLiteracy,3rdEdition Whatisacomputer?Adevicethat:AcceptsinputProcessesdataStoresdataProducesoutput3PracticalComputerLiteracy,3rdEdition Whatisacomputer?Computerinputiswhateveristyped,submitted,ortransmittedtoacomputersystemDatareferstosymbolsthatrepresentfacts,objects,andideasProcessingismanipulationofdataMosttakesplaceincentralprocessingunit(CPU),acomputer’s“brain”Computerprogramsareinstructionsthattellcomputershowtoprocess4PracticalComputerLiteracy,3rdEdition Whatisacomputer?AnoperatingsystemissoftwarethathelpsacomputeroperateefficientlyandkeeptrackofdataApplicationsoftwarehelpsusers“apply”computerstospecifictasksMemoryistemporarystorageStorageispermanentComputeroutputisresultsproducedbycomputer5PracticalComputerLiteracy,3rdEdition Whatisacomputer?6PracticalComputerLiteracy,3rdEdition Howarecomputersclassified?Computersaredividedintofivecategories:HandheldcomputersPersonalcomputersServersMainframecomputersSupercomputers7PracticalComputerLiteracy,3rdEdition Howarecomputersclassified?Handheldcomputer(PDA)featuresinclude:Smallkeyboardortouch-sensitivescreenDesignedtofitinyourpocketRunsonbatteriesUsedwhileholdingit8PracticalComputerLiteracy,3rdEdition Howarecomputersclassified?ApersonalcomputerisdesignedtomeetthecomputingneedsofanindividualDesktopcomputersfitondesksandrunonpowerfromwalloutletsANotebookcomputer(laptop)incorporatesscreen,keyboard,storage,andprocessing9PracticalComputerLiteracy,3rdEdition Howarecomputersclassified?10Atabletcomputerisportable,featuringatouch-sensitivescreenusedforwritingordrawingAserverisusedtoservedatatocomputersconnectedtoanetworkPracticalComputerLiteracy,3rdEdition AmainframecomputeriscapableofsimultaneouslyprocessingdataforhundredsorthousandsofusersAsupercomputerisoneofthefastestcomputersintheworldandcantacklecomplextasksHowarecomputersclassified?11PracticalComputerLiteracy,3rdEdition Cancomputersconnecttoeachother?APDAcanconnecttodesktopwithacableorwirelesslinkPersonalcomputerscanconnecttoeachotherorlargercomputersviawiredorwirelesscomputernetworksAcomputernetworkcanbeasfewastwoorasmanyasthousandsofcomputersTheInternetistheworld’slargestnetwork,connectingmillionsofcomputers12PracticalComputerLiteracy,3rdEdition Cancomputersconnecttoeachother?ComputerscanbeconnectedusingacentralizedmodeloradistributedmodelACentralizedcomputingsystemdependsonacentrally-locatedcomputerforprocessingandstorageAdistributedcomputernetworkspreadstheprocessingandstoragetasksamongmanycomputers13PracticalComputerLiteracy,3rdEdition 14CentralizedcomputersystemDistributedcomputernetworkPracticalComputerLiteracy,3rdEditionCancomputersconnecttoeachother? Cancomputersconnecttoeachother?Large-scalecentralizedanddistributedcomputersystemsareusedformanytasks:Governmentapplicationsincludetaxrolls,censusrecords,andvehicleregistrationCommercialapplicationsincludeinventory,payroll,andpoint-of-saleHospitalandhealthcareorganizationsapplicationsincludepatientrecords,integrateddiagnostictools,patientbilling,andhealthinsuranceclaimsprocessingIneducation,applicationsincludecourseregistration,studentrecords,budgeting,andpayroll15PracticalComputerLiteracy,3rdEdition Whatarethecomponentsofapersonalcomputersystem?Includedinatypicalpersonalcomputersystemare:SystemunitDisplaydeviceKeyboardMouse/TrackpadStoragedevicesMemorycardslotsUSBportsSoundcardandspeakersWebcamNetworkcircuitryPrinter16PracticalComputerLiteracy,3rdEdition Whatarethecomponentsofapersonalcomputersystem?17PracticalComputerLiteracy,3rdEdition What’sinsidethesystemunit?TheSystemcontainsstoragedevices,apowersupply,andmaincircuitboard(motherboard)“Computerchip”,“microchip”,and“chip”aretechnicaljargonforanintegratedcircuitAnintegratedcircuitisasuper-thinsliceofsemi-conductingmaterialpackedwithmicroscopiccircuitelementsAmicroprocessorisanintegratedcircuitdesignedtoprocessinstructions.18PracticalComputerLiteracy,3rdEdition What’sinsidethesystemunit?19PracticalComputerLiteracy,3rdEdition Howdocomputercircuitsmanipulatedata?Mostcomputersareelectronic,digitaldevicesDigitaldevicesworkwithdiscretedata,suchasdigits1and0,orlikealightswitch–onoroffAnalogdevicesworkwithcontinuousdata,likeadimmerswitchwithcontinuousrange20PracticalComputerLiteracy,3rdEdition Howdocomputercircuitsmanipulatedata?Mostcomputersusesimplesttechnologyoftwopossiblestates,likeon-offswitchUsuallyweindicate“on”stateas1and“off”stateas0These1sand0sarereferredtoasbinarydigitsorshortenedtobitsComputersusesequencesofbitstodigitallyrepresentnumbers,letters,punctuationmarks,music,pictures,andvideos21PracticalComputerLiteracy,3rdEdition Howdocomputercircuitsmanipulatedata?Computersemployseveralcodestorepresentcharacterdata,including:ASCII–requiresonlysevenbitsforeachcharacterExtendedASCII–requireseightbitsforeachcharacterEBCDIC–iseight-bittechnologyusedonolder,IBMmainframecomputersUnicodeusessixteenbitsandprovidescodefor65,000characters22PracticalComputerLiteracy,3rdEdition 23PracticalComputerLiteracy,3rdEditionHowdocomputercircuitsmanipulatedata? Whatfactorsaffectcomputerspeed,powerandcompatibility?Computershavethreemajorcomponents:ProcessorMemoryStorageWhenaprogramisstarted,itismovedfromstoragetomemoryTheprocessorfetchesprograminstructionsfrommemory,thenbeginstoexecute24PracticalComputerLiteracy,3rdEdition Ifinstructionsrequiredata,theprocessorfetchesitfromstorage,loadsitintomemory,thentransfersittothemicroprocessorTheresultsaresentbacktomemoryTheresultscanbestoredorsenttooutputprinterorscreen25PracticalComputerLiteracy,3rdEditionWhatfactorsaffectcomputerspeed,powerandcompatibility? Speedandefficiencyofprocessingcyclecanbeaffectedbyfactorssuchas:MicroprocessortypeandspeedMemorycapacityHarddiskdrivespeedandorganizationDisplaycapabilityandvideomemoryNetworkandmodemconnectionspeed26PracticalComputerLiteracy,3rdEditionWhatfactorsaffectcomputerspeed,powerandcompatibility? Whatfactorsaffectspeed,powerandcompatibility?Bitisabbreviatedaslowercase“b”Byteiscomposedofeightbitsandisabbreviatedbyuppercase“B”TheseabbreviationscombinedwithkiloproducespecificationssuchasKB(kilobyte)andKb(kilobit)27PracticalComputerLiteracy,3rdEdition Whatfactorsaffectspeed,powerandcompatibility?Inworldofcomputerskilomeans1024,not1000Kilobitis1024bitsandkilobyteis1024bytesKilobytesisoftenusedwhenreferringtosizeofsmallcomputerfiles28PracticalComputerLiteracy,3rdEdition Whatfactorsaffectspeed,powerandcompatibility?Prefix“mega”meansamillion,orincontextofbitsandbytes,1,048,576MegabitsisusedwhenreferringtospeedofdatatransmissionMegabytesisusedwhenreferringtofilesize,CDcapacity,orvideocardmemorycapability29PracticalComputerLiteracy,3rdEdition Whatfactorsaffectspeed,powerandcompatibility?Gigareferstoabillionor1,073,741,824GigabytesareusedtodescribeRAM,DVD,andharddiskcapacityMainframeandsupercomputersusetera-(trillion),peta-(quadrillion),andexa-(quintillion)30PracticalComputerLiteracy,3rdEdition 31PracticalComputerLiteracy,3rdEditionWhatfactorsaffectcomputerspeed,powerandcompatibility? Whatfactorsaffectspeed,powerandcompatibility?32ThethreemostpopularpersonalcomputerplatformsarePCs,Macs,andLinuxThePCplatformisbasedonthedesignoftheIBMPCTheMacplatformisbasedonaproprietarydesignfortheMacintoshTheLinuxplatformisastandardPCwiththeLinuxoperatingsystemCompatiblecomputersoperateinessentiallythesamewayPracticalComputerLiteracy,3rdEdition What’simportantaboutmicroprocessors?Themostimportant,andusuallythemostexpensive,componentofacomputerCircuitryisgroupedintoimportantfunctionalareasALU(arithmeticlogicunit)performsarithmeticandlogical(suchascomparing)operationsUsesregisterstoholddatathatisbeingprocessedControlunitdirectsmicroprocessortasks33PracticalComputerLiteracy,3rdEdition What’simportantaboutmicroprocessors?Microprocessorspeedismeasuredinmegahertz(MHz)orgigahertz(GHz)MHz=1millioncyclespersecondGHz=1billioncyclespersecondDuringeachcyclethemicroprocessorexecutesinstructionsThefastertheclockspeed,themoreinstructionsexecutedpersecond34PracticalComputerLiteracy,3rdEdition What’simportantaboutmicroprocessors?MicroprocessorsarealsoratedbywordsizeManyprocessa32-bitword64-bitavailable,andarefasterthen32-bitunitsMicroprocessorsmanufacturedbyseveralcompanies:IntelAMDMotorolaIBM35PracticalComputerLiteracy,3rdEdition 36PracticalComputerLiteracy,3rdEditionWhat’simportantaboutmicroprocessors? What’simportantaboutcomputermemory?RAM(randomaccessmemory)isatemporaryholdingareafordata,applicationprograminstructions,andtheoperatingsystemRAMisthe“waitingroom”forprocessorWhenprogramisstarted,itisheldinRAMuntilneededandremainsthereuntilprogramisclosed37PracticalComputerLiteracy,3rdEdition What’simportantaboutcomputermemory?RAMalsoholdsdataMostRAMisvolatile,whichmeansitneedselectricalpowertoholddataIfpowergoesout,orcomputeristurnedoff,datastoredinRAMisinstantlyandpermanentlylostItisimportanttofrequentlysaveworktoapermanentstoragearea,suchasharddisk,asyouwork38PracticalComputerLiteracy,3rdEdition What’simportantaboutcomputermemory?RAMalsoholdsoperatingsysteminstructions,loadedeachtimeyouturnonyourcomputerandhelduntilitisturnedoffRAMcapacityismeasuredinmegabytesorgigabytesToday’scomputershavebetween512megabytesand8gigabytesofRAM39PracticalComputerLiteracy,3rdEdition 40PracticalComputerLiteracy,3rdEditionWhat’simportantaboutcomputermemory? What’simportantaboutcomputermemory?MostcomputersalsocontainROM(readonlymemory)–atypeofmemorythatholdsthecomputer’sstartuproutineWhereasRAMistemporaryandvolatile,ROMispermanentandnon-volatile41PracticalComputerLiteracy,3rdEdition Whydocomputersusemultiplestoragedevices?Computersfeaturemultiplestoragedevices,suchas:Harddiskdrive-themainstoragedeviceinmostcomputersProvideslotsofstoragecapacityProvidesfastaccesstofilesEconomicalCapacityismeasuredingigabytesandspeedinmilliseconds(ms)orrevolutionsperminute(RPM)42PracticalComputerLiteracy,3rdEdition 43PracticalComputerLiteracy,3rdEditionWhydocomputersusemultiplestoragedevices? Whydocomputersusemultiplestoragedevices?ACD(compactdisk)provides650-700MBofstorageADVD(digitalvideodiskordigitalversatiledisk)isavariationwithacapacityof4.7GBCanbedoubledwithduallayertechnologyBlu-Rayisstoragemediumwith25GBcapacityforsinglelayerCD’s,DVD’s,andBD’sare:DurablestorageUnaffectedbymagneticfieldsDustanddirtcanbecleanedoffBiggestthreatarescratches44PracticalComputerLiteracy,3rdEdition Whydocomputersusemultiplestoragedevices?CDsandDVDscomeinseveralvarieties:Readonly(ROM)–permanentdatastoredduringmanufacturingRecordable(R)–Awritabledrivecanstoredatabutitcan’tbechangedRewritable(RW)–canbechangedmanytimes,muchlikeaharddrivebutmuchslower45PracticalComputerLiteracy,3rdEdition AUSBflashdriveisapopularremovable,portablestoragedeviceAboutthesizeofahighlighterpenVerydurableOpen,edit,delete,andrunfilesjustasiftheywereonharddriveUsesolidstatestoragetechnologyProvidesfastaccesstodataanduseslittlepowerWhydocomputersusemultiplestoragedevices?46PracticalComputerLiteracy,3rdEdition Whydocomputersusemultiplestoragedevices?Inadditiontostoragedevicesconnectedtocomputer,datacanbestoredononlinestorage47PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?Largeorganizationsprotectequipmentfromtheftwithhigh-techsecuritysystemsProtectpersonalcomputerbylockingtodeskorlockingroomWhentravelingbyair,carryitinyourcarry-onbag48PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?MakesurecomputerisbalancedsafelyondeskorrestingonfloorWhencarryingnotebookcomputer,usepaddedcarryingcaseWhentransportingdesktop,useoriginalboxorprotectitwithfoampadding49PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?EnvironmentalfactorscandodamageExcessheatcandamagecircuitryHighhumiditycancorrodecontactsandcablesWaterleakscanshortoutcircuitsMagneticfieldscanerasedataDust,dirt,andairpollutioncancauseoverheatingandclogupmechanicalparts50PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?RoutinecleaningofmouseandkeyboardcankeepthemworkingsmoothlyFollowmanufacturer’sinstructionsforcleaningtokeepprinterfromjammingandprintheadfromsmearingKeepfloppydisksandharddisksawayfromstrongmagneticfields51PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?ComputersarevulnerabletopowerirregularitiesMakesurepowercableispositionedsoitcan’tbeaccidentallydisconnectedWhengoingtoanothercountry,ensureyourequipmentconformstopowersystemsUsesurgestripstoprotectagainstpowerspikesandsurgesToprotectagainstpoweroutages,youcanconnecttouninterruptiblepowersupply52PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?Ownersshouldperiodicallymakebackupsofdata,runadefragmentationutility,andupdateviruscheckingsoftwareConsiderfollowingguidelineswhentroubleshooting:MakesureequipmentispluggedinCheckallcablesGetclearideaofproblembytryingtoisolatemalfunctioningdeviceorreplicatingsteps53PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?Attemptbasicsolutions,suchasrestartdeviceorrebootingLookforinformationinmanuals,theWeb,ormanufacturer’ssupportlineWhencommunicatingwithtechnicians,explainproblemaccuratelyandpreparetoanswerquestionsaboutbrand,model,operatingsystem,andapplicationsoftware54PracticalComputerLiteracy,3rdEdition Whatkindofprotectionandmaintenancedoesacomputerrequire?FollowinstructionscarefullyandcompletelyBeforeyouresumenormaloperations,makesureproblemisfixedSavearecordoftheproblemandsolutionforfutureuse55PracticalComputerLiteracy,3rdEdition'