qMemUMB
UMB
Upper Memory Block
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Traditionally, memory between 640K and 1 MB has
been "reserved" for special purposes such as
video memory and ROM.
On 386+ computers, it is possible to map extended
memory into the unused areas of reserved memory.
The resulting islands of memory are called
Upper Memory Blocks, or UMBs.
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■ DOS fn 5803H (along with fn 48H) provide
access to UMBs. See UMB in the Index.
■ DEVICE=HIMEM.SYS ─┐ use in CONFIG.SYS
DEVICE=EMM386.EXE │ to enable access
DOS=UMB ─┘ to UMBs
■ DEVICEHIGH= load device drivers into UMBs