Memory used through EMS. In systems based on Intel 80386 or later processor expanded memory is part of the extended memory that is mapped into the {expanded memory page frame} by the processor. The mapping is controlled by the EMM. In earlier systems, a dedicated EMSHardware adaptor is needed to map memory into the page frame. In both cases, an appropriate device driver is needed for the proper communication between Hardware and EMM. (1996-01-10)