Expanded Memory Specification
Expanded Memory Specification
(storage)Expanded memory is provided through a page frame of atleast 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 accessiblethrough interrupt 67H.
In 8086 or 8088 based systems this is the only way to usememory beyond conventional memory. In systems based on80286 or later, XMS and HMA provide alternative methods.
EMS was developed jointly by Lotus, Intel, and Microsoftprior to 1988. Accordingly, this specification is sometimesreferred to as LIM EMS.
A complete discussion of EMS and programming examples can befound in ["PC System Programming for developers", 1989, ISBN1-55755-035-2 (Book only) and ISBN 1-55755-036-0 (Book anddiskette)].
EEMS, a competing expanded memory management standard, wasdeveloped by AST Research, Quadram and Ashton-Tate.
See also upper memory block.