Објашњење
CommonexternalstorageofPCsarefloppydiskstorage,harddiskstorage,opticaldiskstorageWait.Therearetwotypesofdisks:floppydisksandharddisks.Therearethreetypesofopticaldiscs:CD-ROM,write-onceopticaldiscWORMandrewritableopticaldiscMO.
Увод
Therearemanytypesofmemory,whichcanbedividedintomainmemoryandauxiliarymemoryaccordingtotheiruse.Mainmemoryisalsocalledinternalmemory(memoryforshort),andauxiliarymemoryisalsocalledexternalmemory(Referredtoasexternalstorage).Themostprominentfeatureoftheinternalmemoryisthefastaccessspeed,butthecapacityissmall,andthepriceisexpensive;theexternalmemoryischaracterizedbythelargecapacity,lowprice,buttheaccessspeedisslow.Theinternalmemoryisusedtostoretheprogramsanddatathatareneededimmediately;theexternalmemoryisusedtostorethetemporarilyunusedprogramsanddata.Informationisfrequentlyexchangedbetweeninternalstorageandexternalstorage.Externalstorageisusuallymagneticmediaoropticaldiscs,suchasharddisks,floppydisks,tapes,CDs,etc.,whichcanstoreinformationforalongtimeanddonotrelyonelectricitytostoreinformation.However,drivenbymechanicalcomponents,thespeedismuchslowerthanthatoftheCPU.
Floppydisk:Thefloppydiskusesasoftpolyestermaterialtomakeaprototypefilm,andthetwosurfacesarecoatedwithmagneticmaterials.Thecommonlyusedfloppydiskhasadiameterof3.5inchesandastoragecapacityof1.44MB.Thefloppydiskusesafloppydiskdrivetoreaddata.
Удиск:Удискisalsocalled"flashdisk",whichcanstoredatathroughtheUSBportofthecomputer.Comparedwithfloppydisks,Удискshavereplacedfloppydisksduetotheirsmallsize,largestoragecapacityandconvenientportability.
Хард диск:Theharddiskiscomposedofaluminumalloyoriginaldiskscoatedwithmagneticmaterials,andeachharddiskiscomposedofseveralmagneticdisks.
Tapestorage:MagnetictapeisalsocalledsequentialaccessstorageSAM.Ithasalargestoragecapacity,butthesearchspeedisveryslow,andisgenerallyonlyusedasadatabackupstorage.Thereare3typesoftapedrivesusedincomputersystems:reel-to-reeltapedrives,datastreamtapedrivesandspiralscantapedrives.
CD-ROMstorage:CD-ROMreferstoadiscthatusesopticalmethodsforinformationstorage.Itappliesopticalstoragetechnology,thatis,usingalasertowriteinformationonacertainmedium,andthenusingthelasertoreadtheinformation.Discstoragecanbedividedinto:CD-ROM,CD-R,CD-RW,andDVD-ROM,etc.
Тип
Дискете, чврсти дискови, оптички дискови, Удискови и траке су реално екстерно складиште.
FromtheworkingprincipleofvonNeumann'sstoredprogramandthecompositionofthecomputer,thecomputerisdividedintoarithmeticunit,controller,memoryandinput/outputdevice.Thememoryherereferstothememory,andtheharddiskBelongstoinput/outputdevices.
TheprogramcodeanddatarequiredforCPUoperationscomefromthememory,andthethingsinthememorycomefromtheharddisk,sotheharddiskdoesnotdirectlydealwiththeCPU.
У поређењу са меморијом, екстерном меморијом харддиски.
Memoryisusedtostoredata.Thememoryhashigh-speedcacheandmemory.TheinternalstorageofthecomputerandtheexternalstorageareexternalstoragesimilartoУдиск.
Theinternalmemoryisfastandexpensive,andthecapacityissmall.Thedatainthememorywillbelostafterapowerfailure.(ROMisnotlostwhenpowerisoff)
Externalmemoryhaslowunitprice,largecapacity,slowspeed,anddatawillnotbelostafterpoweroff.
Индикатори учинка
Хард диск
●Capacity-usuallyreferredtoasthecapacityreferstothetotalcapacityoftheharddisk,generallytheunitdefinedbytheharddiskmanufactureris1GB=1000MB,Thesystemdefines1GB=1024MB,sotherewillbeasituationwherethenominalvalueontheharddiskisgreaterthantheformattedcapacity.Thisisconsideredanindustrypracticeandisnormal.
●Thecapacityofasinglediscreferstoadisc.Thenumberofbytesthatcanbestored,thesingle-diskcapacityofaharddiskisgenerallymorethan20GB.Withtheincreaseofthesingle-diskcapacityoftheharddisk,thetotalcapacityoftheharddiskcanreachhundredsofGorevenafewterabytes(commerciallypurchasedharddiskcapacity)Ifitis1TB,itmayactuallyonlybe1000GBinsteadof1024GB.Inthetruesense,1TB=1024GB.).
Rotationspeed-Rotationspeedreferstotherotationspeedofthemotorspindleintheharddisk,andtheunitisRPM(revolutionsperminute).Rotationspeedisoneofthedeterminantsoftheinternaltransmissionrateoftheharddisk,anditsspeedisveryslow.Toalargeextent,itdeterminesthespeedoftheharddisk,anditisalsoanimportantcriteriontodistinguishthegradeoftheharddisk.Atpresent,thegeneralharddiskspeedis5400rpmand7200rpm.Thehighestspeedcanreachmorethan10,000rpm.
●ThehighestinternalTransmissionrate-Thisisthetransmissionrateoftheouterringoftheharddisk.Itreferstothehighestdatatransmissionratebetweenthemagneticheadandthehigh-speeddatacache,inMB/s.Theperformanceofthehighestinternaltransmissionrateisrelatedtotheharddiskspeedandthestoragedensityofthedisk.(Singlediskcapacity)isdirectlyrelated.
●AverageseektimeAverageseektimereferstothetimeittakesfortheharddiskheadtomovetothetrackwherethedataislocated,inmilliseconds(ms),theaverageoftheharddiskTheseektimeisgenerallylessthan9milliseconds.Theshortertheaverageseektime,thehigherthecapacityoftheharddisktoreaddata.
Удиск
●Теоријска брзина читања података: 18МБ/с
●Теоријска брзина писања података: 17МБ/с
●Инсталација драјвера (осим за виндовс98)
●Нема додатног напајања, само Усббустогетнапајање
● Велики капацитет, много варијанти
●Withwriteprotectionswitchtopreventfilesfrombeingerased,antivirus
●ЛЕДиндикаторсветлоснаиндикацијаРадни статус
●Мала и лагана: око 20 г