资料来源 : Free On-Line Dictionary of Computing

Expanded Memory Specification
     
         (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)