CEMM
Intel 80386 | |
---|---|
Type | Expanded memory manager |
CEMM, for
It was present in Compaq DOS 3.10, shipping with the Compaq Deskpro 386 in September 1986.[1][2]
Overview
In 1986, Compaq was the first vendor to ship a PC compatible computer with a 386 CPU, the Deskpro 386, and it was natural for them to develop solutions leveraging the specific features of their new hardware and in this case allowing existing EMS-compatible DOS programs to access all the memory.
The implementation was not without its drawbacks. Although CEMM was called an "expanded memory manager", it was really a tiny,
Because CEMM put the CPU into protected mode, other programs (
Compaq filed for a patent on the technology in 1987. The patent was granted in 1990 and probably expired in 2007. Compaq was the creator of this technology and the first company to use it. However, over time,
See also
- QEMM
- EMM386
- Real mode
- Unreal mode
- Protected mode
- Virtual 8086 mode
- Conventional memory
- Extended memory (XMS)
- Expanded memory (EMS)
- High Memory Area(HMA)
- Upper Memory Area(UMA)
References
External links
- U.S. patent 4,926,322 - Software emulation of bank-switched memory using a virtual DOS monitor and paged memory management