Introductio
Externalequipmentreferstoequipmentconnectedoutsidethecomputerhost.Itisgenerallydividedintoinputequipment,outputequipmentandexternalmemory.Externalequipmentisanimportantpartofthecomputersystem.Playtheroleofinformationtransmission,transferandstorage.Thethreetypesofequipmentareintroducedbelow.
Inputdevice
Keyboard
Thekeyboardispartofthecomputerhardware.Itisoneofthemainequipmentforinputtinginstructionsandoperatingthecomputer.Chinesecharacters,EnglishLetters,numbers,andpunctuationmarksareenteredintothecomputerthroughthekeyboard.Therearemanystylesofkeyboards,weusuallyuse101-key,105-key,108-key,etc.keyboards.Nomatterwhatkindofkeyboard,itsfunctionsandkeyarrangementarebasicallydividedintofiveareas:functionkeyarea,typingkeyarea,editingkeyarea,numerickeyboard,alsocalledsmallkeyboard,andindicatorarea.
Thecorrectoperationofthekeyboardcanreduceinputerrorsandreducefatigue.Sitinfrontofthecomputerwithyourelbowsclosetoyourbody,andyourwristsshouldbestraight.Tenfingersbendslightlyonthebasickeys.Adjustyoursittingposture,keepyourbodystraightandrelax,anddon’tbendyourback.Onlywhenyouinputthekeyscanyoupressthekeysaccuratelyandquickly.Aftertheinputiscompleted,thefingersreturntothebasickeypositions.Thestrengthshouldbeaverage,andthespeedshouldbeimprovedaccordingtothelevelofproficiency.
Muris
ThemouseisthebasiccontrolinputdeviceofWindowsandiseasiertousethanthekeyboard.ThisisduetothegraphicalfeaturesofWindowsthatneedtobespecifiedwiththemouseandmovedandclickedonthescreen.
Peninputdevice
TheappearanceofpeninputdeviceprovidesconvenienceforinputtingChinesecharacters,anduserscaninputChinesecharacterseasilywithoutlearningotherinputmethods.Atthesametime,italsohasthefunctionsofakeyboard,amouseandawritingpen,whichcanreplacethekeyboardandmouseforinputtingtext,commandsanddrawing.
Scanner
Inactualwork,theremaybealargenumberofdrawings,photosandvariouscharts,whichneedtobeinputintothecomputerforprocessing,butpictures,photosandothermaterialsarealsoIfyoucan’tdirectlyrelyonkeyboardandmouseinput,evenifyoucaninput,relyingonlyonkeyboardandmousewillbeaveryheavywork.Therefore,thescannerisnecessarytohandlethesetasks.Itinputsvariouspictures,drawings,andtextsintothecomputerthroughadedicatedscanningprogramanddisplaysthemonthescreen.Thenwecanusesomegraphicsandimageprocessingsoftwaretoperformvariouseditingandpost-processingonthepicturesandothermaterials.
Therearemanytypesofscanners.Usually,peopledividescannersintothreetypes:handheld,desktopandroller.Accordingtothetypeofscannedimage,itcanbedividedintoblack-and-whitescannerandcolorscanner.
Digital Camera
Theso-calleddigitalcameraisaspecialcamerathatcantakepicturesandconvertthecapturedscenesintoimagesstoredindigitalformatthroughinternalprocessing.Differentfromtraditionalcameras,digitalcamerascantakephotosinstantly,andyoucanseetheeffectsofthephotosyoutakethroughtheLCD.Iftheeffectsarenotgood,youcandeletethemimmediatelyandtakethenextshot.Thephotosittakesarefirstsavedinthestoragemedium,andthenoutputondemand.Digital Camerascanbedirectlyconnectedtoacomputer,TVorprinter.Undercertainconditions,digitalcamerascanalsobedirectlyconnectedtomobilephonesorhandheldPCs.Sincetheimageisprocessedinternally,theusercanimmediatelycheckwhethertheimageiscorrect,anditcanbeprintedoutorsentbye-mailimmediately.
Digital Camera
Digital Camerareferstoacamerawhoseimageprocessingandsignalrecordingallusedigitalsignals.Thebiggestfeatureofthiscameraisthatthesignalrecordedonthetapeisadigitalsignal,notananalogsignal.Digital Camerashavethefollowingcharacteristics:
1.Goodimagequality:Theuseofdigitalsignalscanneglecttheinfluenceofnoiseintroducedintothecircuitpart.Theplaybackimageisclearandclean,andthequalityisexcellent;theerrorcorrectioncodingisadoptedintherecordingprocess,sothatthesignallossofthetapeduringplaybackcanbeeffectivelycompensated,andtheimagelossisless.
2. Est ergo secundum rationem altitudinis et themachineissmall.
3.Highreliability.
4.Reducethecostofuse:Becausethetensionofthedigitalcameraisverysmall,thewearofthemagneticheadandthetapeiscorrespondinglyreduced,sothatthemaintenancecostiscorrespondinglyreduced,therebyreducingthecostofuse.
5.Perfectrecordingsoundquality:TheaudiopartofthedigitalvideocameraisrecordedonthetapeindigitalPCMmode,withextremelyhighfidelity.
Outputdevice
Ostendere
Thedisplayisanoutputdevice,whichacceptsR(red),G(green),Bthrougha15PIND-typeconnector(Blue)signalandfieldsynchronizationsignaltoachievethepurposeofdisplay.Thedisplaymustbecompatiblewithmultipledisplaymodesandhorizontalfrequencybandwidth.Forexample,thehorizontalfrequencyofacommonSVGAdisplaycanrangefrom31.5KHZto38KHZ,andthedisplaymustautomaticallyadjustthehorizontalfrequency,fieldfrequency,amplitudeandbrightnessofthedisplayimageaccordingtodifferentdisplays.Andotherparameters.
Therearemanytypesofdisplaysonthemarket,andthemostpopularonesarenon-radiationliquidcrystaldisplaysandotherhealthierdisplays.
Printer
Inourdailywork,weoftenneedtoprintoutthedocumentsandpicturesthatwehavedoneonthecomputer.Thisrequiresaprinter,sotheprinterisgenerallyastylusprinter,Inkjetprintersandlaserprintersarethemostcommonlyused.
Duetoslowspeedandlowprecision,dotmatrixprintershavebeengraduallyeliminatedfromthehomeprintermarket.However,thecostofinjectionconsumablesislow,anditcanbemulti-layered,makingitanirreplaceablepositioninbanking,securitiesandotherfields.Laserprintershavethecharacteristicsofhighquality,highspeed,lownoise,easymanagement,etc.,andhaveoccupiedmostofthemarketintheofficefield.Comparedwiththeformertwo,inkjetprintersarealsothemainstreaminthemarket.
So,whenusingtheprinter,weshouldpayattentiontothefollowingpoints:
1.Theprintershouldbeplacedinarelativelylargespaceandnottoofarawayfromthehostandthepoweroutlet.
2.Tounderstandthebeepingsoundoftheprinter,inordertoknowitsworkingstatusatanytime.Mostprintersbuzzerwithalongbeeptoindicatethatitisreadytostartprinting,andashortbeeptoindicatethattheprinterismalfunctioning.Atthesametime,manyprintersarealsoequippedwithindicatorlights,sothatuserscanaccuratelyunderstandthestatusoftheprinter,andcanjudgewhatiswrongwiththeprinteraccordingtothebeepingsoundtohelpuserschecktheprinter.
3.Whenprintingmultiplesheetsofpaperatthesametime,shakethepaperaparttoavoidpaperjams.
4.Donotopenthefrontpaneltoprint.
Opticaldiscburner
Theopticaldiscburnerlooksnodifferentfromanordinaryopticaldrive,butitismuchmorepowerfulthanCD-ROMinfunction.Intermsoffunction,recordersaremainlydividedintoCD-RrecordersandCD-R/Wrecorders.CD-RburnerscanburnCD-Rdiscs,andCD-R/WburnerscanalsouseCD-R/WdiscsinadditiontoCD-Rdiscs.CD-Rdisccanonlybewrittenonce(supportingsegmentedrecording),andCD-R/Wcanbeerasedandwrittenmanytimes.Therefore,majorrecordermanufacturershavestoppedproducingCD -RrecordersandswitchedtoCD-RWrecorders.
Externaltorage
Harddiskstorage
Harddiskstorage(harddisk)referstoamagneticsurfacestoragedevicewhoserecordingmediumisaharddisk.Inthecomputer,theharddiskisanecessaryexternalstoragedevice.Ithasthecharacteristicsoflargestoragecapacityandfastaccessspeed.Withtheimprovementofharddiskmanufacturingtechnology,itspriceisgettinglowerandlower,andthecostperformanceisgettinghigherandhigher.
Removablestorage
(1) Removableharddisk:
Removableharddiskisastoragemediumthatemphasizesportabilitybyusingharddiskasthestoragemedium.Itencapsulatesthemicroharddiskinaharddiskbox,anditsdatareadandwritemodeisthesameasthatofastandardharddisk.Therearetwotypesofmobileharddisks:2.5Inch(fornotebookcomputers)and3.5Inch(fordesktopcomputers).2.5InchTheharddiskboxofthemobileharddiskgenerallydoesnothaveanexternalpowersupply.Theharddiskboxofthe3.5Inchmobileharddiskgenerallycomeswithanexternalpowersupplyandacoolingfan.
(2) Udiskstorage
UdiskisakindofmobilestoragethatusesthecombinationofUSBinterfaceandflashmemory(FlashMemory)technology,alsoknownasFlashdrive.Ithastheadvantagesofsmallsize,lightweight(approximately20grams),noise-freework,noexternalpowersupply,andsupportforplug-and-playandhot-plugging,makingitanidealportablestoragedevice.
Udiskstoragecapacityisusually4GB,8GB,10GB(orevenlarger),whichcanmeetdifferentneeds.Itreadsandwritesfasterthandisks,hasmorerepeatederasingtimes,andretainsdataforalongtime.Itisnotonlysuitableforstoringgeneralprogramsanddata,butalsocansimulateopticaldrivesandharddiskstostarttheoperatingsystem.
(3) Memorycard
Memorycard(memorycard)isasolid-statememory,usuallyrectangularorsquare.Itgenerallyusesflashmemoryasastoragemedium,alsoknownasaflashmemorycard.Thememorycardcanprovideastorageformthatcanbereadandwrittenrepeatedlywithoutanexternalpowersupply.Therearemanytypesofmemorycards,suchasCFcard(standardmemorycard),MMCcard(multimediacard),SDcard(securedigitalcard)Wait.Thememorycardhastheadvantagesofsmallsize,convenientcarrying,simpleuse,etc.,butitisnecessarytoconfigureacardreadertoreadandwritetheinformationinthememorycard.
(4) SolidStateDisk
SolidStateDisk(SolidStateDisk,SSD),alsocalledelectronicharddiskorsolidstateelectronicdisk,consistsofacontrolunitandAharddiskcomposedofsolid-statestorageunits(mainlyNANDflashdrives).Simplyput,itisaharddiskmadeofanarrayofsolid-stateelectronicmemorychips.
(5) Floppydisk
Floppydiskistheearliestremovablemediumusedinpersonalcomputers(PC).Floppydiskisanecessarypieceofhardwareonearlycomputers,anditisalsotheearliestremovablemediumusedoncomputers.Butfromtoday'sperspective,floppydiskshavesmallcapacity,highcostperunitcapacity,slowspeedandpoorreliability.Oncealongsidefloppydisks,therewerelargercapacityZIP,LS-120andotherrewritableremovablemedia,butitwastheemergenceofUdisks(flashdisks)thatgraduallyreplacedthelong-establishedfloppydisks.
Opticalmemory
Opticalmemoryisamemorythatusesopticalprinciplestoreadandwriteinformation.Ithashighreliability,longlife,largestoragecapacity,lowprice,canwithstandtouchanddustinterference,andisnoteasytobescratched,buttheaccessspeedanddatatransferratearemuchlowerthanharddisks.Theopticaldiscstorageconsistsofanopticaldisc(opticaldisc)andanopticaldiscdrive(opticaldrive).CDisusedtostoreinformation,CDdriveisusedtoreadandwriteCDinformation