What Are the Different Types of OCD?

Memory type refers to different types of memory transmission types, which have different types of memory in terms of transmission rate, operating frequency, working method, working voltage, etc. The main types of memory in the market are SDRAM, DDR SDRAM and RDRAM.

Memory type

Memory type refers to the different types of memory transfer types.

FPM memory

FPM is the abbreviation of Fast Page Mode. It is the memory type of older PCs.

Universal memory, every 3

Server and

Basic memory occupies 0 ~ 640KB address space.

Reserved memory occupies 640KB 1024KB address space. Allocate to display buffer memory, ROM on each adapter card and system ROM BIOS, and the remaining space can be used as upper memory UMB. The UMB's physical memory is taken from the physical expansion memory. This range of physical RAM can be used as Shadow RAM.

Upper memory (UMB) is established by using unallocated address space in reserved memory, and its physical memory is obtained from physical expansion memory. UMB is managed by EMS, and its size can be set by the EMS driver.

High-end memory (HMA) The first 64KB area (1024KB 1088KB) in the extended memory. Created and managed by HIMEM.SYS.

XMS memory meets the extended memory area managed by XMS specifications. Its driver is HIMEM.SYS.

EMS memory meets the expanded memory area managed by EMS specifications. Its driver is EMM386.EXE and so on.

Memory: Random memory (RAM), which mainly stores running programs and data to be processed.