EMS emulator - technical definition

Prior to the 386, it was a slow, low-cost software alternative to an EMS board. In XTs and ATs, it simulated EMS memory in extended memory or on disk. On 386s, it referred to a memory manager (EMM) that created EMS from extended memory. Technically, the 386 architecture does not emulate EMS, it maps extended memory into the page frame. See EMS.