Primary vs Secondary Memory | Auxiliary Storage Devices
Ib lub khoos phis tawj muaj cov hierarchy ntawm lub cim xeeb rau khaws cov ntaub ntawv. Lawv txawv ntawm lawv lub peev xwm, ceev thiab tus nqi. Lub cim xeeb tseem ceeb (tseem hu ua lub cim xeeb tseem ceeb) yog lub cim xeeb uas tau nkag ncaj qha los ntawm CPU los khaws thiab khaws cov ntaub ntawv. Lub cim xeeb thib ob (tseem hu ua lub cim xeeb sab nraud lossis lub cim xeeb pab) yog cov cuab yeej khaws cia uas tsis tuaj yeem siv ncaj qha los ntawm CPU thiab siv los ua cov khoom khaws cia ruaj khov uas khaws cov ntaub ntawv txawm tias tom qab lub hwj chim kaw.
Lub Cim Tseem Ceeb yog dab tsi?
Lub cim xeeb tseem ceeb yog lub cim xeeb uas nkag ncaj qha los ntawm CPU los khaws thiab khaws cov ntaub ntawv. Feem ntau, lub cim xeeb tseem hu ua RAM (Random Access Memory). Nws yog lub cim xeeb tsis muaj zog, uas poob nws cov ntaub ntawv thaum lub hwj chim kaw. Lub cim xeeb tseem ceeb yog nkag ncaj qha los ntawm CPU los ntawm qhov chaw nyob thiab lub cim xeeb tsheb npav thiab nws tau nkag mus tas li los ntawm CPU kom tau txais cov ntaub ntawv thiab cov lus qhia. Tsis tas li ntawd, cov khoos phis tawj muaj ROM (Nyeem Tsuas Nco), uas tuav cov lus qhia uas tau ua ntau zaus xws li kev pib ua haujlwm (BIOS). Qhov no yog lub cim xeeb tsis hloov pauv uas khaws nws cov ntaub ntawv thaum lub hwj chim kaw. Txij li thaum lub cim xeeb tseem ceeb nkag mus ntau zaus, nws yuav tsum tau nrawm dua. Tab sis lawv me me thiab kuj raug nqi.
Secondary Memory yog dab tsi?
Lub cim xeeb thib ob yog lub cuab yeej cia uas tsis tuaj yeem nkag ncaj qha los ntawm CPU thiab siv los ua cov cuab yeej khaws cia ruaj khov uas khaws cov ntaub ntawv txawm tias tom qab fais fab tuag. CPU nkag mus rau cov khoom siv no los ntawm kev tawm tswv yim / tso tawm channel thiab cov ntaub ntawv raug xa mus rau thawj lub cim xeeb los ntawm lub cim xeeb thib ob ua ntej nkag mus. Feem ntau, hard disk drives thiab optical storage devices (CDs, DVDs) yog siv los ua lwm yam khoom siv hauv cov khoos phis tawj niaj hnub no. Nyob rau hauv ib tug thib ob cia ntaus ntawv, cov ntaub ntawv yog teem nyob rau hauv cov ntaub ntawv thiab directory raws li ib tug ntaub ntawv system. Qhov no kuj tso cai rau kev koom nrog cov ntaub ntawv ntxiv nrog rau cov ntaub ntawv xws li kev tso cai nkag, tus tswv, lub sijhawm nkag mus dhau los, thiab lwm yam. Tsis tas li ntawd, thaum lub cim xeeb thawj zaug tau sau, lub cim xeeb thib ob yog siv los ua ib ntus cia rau khaws cov ntaub ntawv siv tsawg kawg hauv thawj lub cim xeeb.. Cov khoom siv cim xeeb thib ob yog tus nqi qis dua thiab loj dua. Tab sis lawv muaj lub sijhawm nkag mus ntau.
Qhov txawv ntawm Lub Tsev Kawm Ntawv Qib Siab thiab Qib Siab
Lub cim xeeb tseem ceeb yog lub cim xeeb uas nkag ncaj qha los ntawm CPU los khaws thiab khaws cov ntaub ntawv, thaum lub cim xeeb thib ob tsis tuaj yeem siv ncaj qha los ntawm CPU. Lub cim xeeb tseem ceeb yog nkag mus siv qhov chaw nyob thiab cov ntaub ntawv tsheb npav los ntawm CPU, thaum lub cim xeeb thib ob nkag mus siv cov khoom nkag / tso tawm. Lub cim xeeb tseem ceeb tsis khaws cov ntaub ntawv thaum lub hwj chim raug kaw (volatile) thaum lub cim xeeb thib ob khaws cov ntaub ntawv thaum lub hwj chim kaw (tsis yog-volatile). Tsis tas li ntawd, lub cim xeeb tseem ceeb yog qhov nrawm heev piv rau lub cim xeeb thib ob thiab muaj lub sijhawm nkag mus tsawg dua. Tab sis, thawj cov khoom siv nco tau kim dua piv rau cov khoom siv cim xeeb thib ob. Vim li no, feem ntau lub computer muaj lub cim xeeb me me thiab lub cim xeeb loj dua.
