EMS and EEMS

Updated: 09/12/2023 by Computer Hope

EMS and EEMS may refer to any of the following:

EMS in light blue lettering.

1. Short for emergency management services, EMS is a way of accessing the Microsoft Windows bootloader through an RS-232 serial console interface using bootcfg or bcdedit.

2. With memory, EMS and EEMS are an extended portion of memory. Below are additional details about all extended memory on computers running Microsoft operating systems.

EEMS

A competing standard to EMS is EEMS, developed by Ashton-Tate, AST Research, and Quandram.

Extended memory

Extended Memory is not configurable and unavailable to programs other than those that run in Microsoft Windows and OS/2.

Expanded memory

Expanded Memory utilizes EMS allowing DOS programs and other programs to use the available memory above 1 MB.

EMS

EMS (expanded memory specification) allows IBM-compatible computers to access more than 1 MB. Early IBM-compatible computers running MS-DOS used 640 KB (conventional memory) + 384 KB (upper memory) = 1024 KB or 1 MB total memory for MS-DOS programs. EMS allowed computer programs to access memory above that 1 MB. However, due to of out of memory issues still being encountered by users, LIM EMS was created.

XMS

Developed by AST, Intel, Lotus, and Microsoft, XMS (extended memory specification) allows software access to more than 1 MB.

Computer acronyms, DPMI, EMM, EMM386.EXE, Himem.sys, LIM EMS, Memory terms, Protected mode