Expanded Memory Specification definition
<storage> (EMS) An IBM PC memory paging scheme enabling
access to memory other than conventional memory in real
mode.
Expanded memory is provided through a page frame of at
least 64 kilobytes in the reserved memory address region.
Access to this memory is provided by an expanded memory
manager (EMM) software. The EMM functions are accessible
through interrupt 67H.
In 8086 or 8088 based systems this is the only way to use
memory beyond conventional memory. In systems based on
80286 or later, XMS and HMA provide alternative methods.
EMS was developed jointly by Lotus, Intel, and Microsoft
prior to 1988. Accordingly, this specification is sometimes
referred to as LIM EMS.
A complete discussion of EMS and programming examples can be
found in ["PC System Programming for developers", 1989, ISBN
1-55755-035-2 (Book only) and ISBN 1-55755-036-0 (Book and
diskette)].
EEMS, a competing expanded memory management standard, was
developed by AST Research, Quadram and Ashton-Tate.
See also upper memory block.
(1996-01-10)
Nearby terms:
expanded memory « expanded memory manager « expanded memory page frame « Expanded Memory Specification » expansion card » expansion slot » expect
|
