2019年10月31日 · I had always assumed that EMM386.EXE was responsible for managing the Upper Memory Blocks - UMBs - the memory space between 640KiB and 1MiB in real mode x86. For example, on MS-DOS 6.22, help emm386.exe shows: Provides access to the upper memory area and uses extended memory to simulate expanded memory

Typical 386+ DOS installations use EMM386 or a similar memory manager to map memory using the 386’s paging features (in V86 mode). Another approach, which works with 286-class systems too, is to use a chipset-specific driver such as UMBPCI (on Pentium-class systems) or a chipset-aware memory manager such as The Last Byte Memory Manager; these ...

2025年2月11日 · The EMM386 may be a requirement for some other purposes too. For example the Gravis UltraSound sound card could be made to emulate a Sound Blaster and a Roland MT-32 with a software emulator, as the emulator can command the EMM386 to trap IO port accesses that happen in the VM86 task where the DOS game runs.

2019年2月22日 · himem.sys emm386.exe ansi.sys sbide.sys ctmouse.exe smartdrv.exe doskey.com mscdex.exe I'm loading all these devices (including part of DOS itself) into High Memory and the MEM command is showing that the largest executable program size is 618 K, which I think means that DOS was successful in allocating all the drivers into upper memory, …

2023年5月1日 · Another interesting scenario may be that windows used the big real mode during startup - that mode is set up by himem.sys if it itself was started in real mode. (of course this doesn't apply to the case when also emm386 is loaded, which needs an …

2024年8月15日 · Rather, they try to allocate memory from the UMA ("upper memory"). DOS technically uses the XMS interface to access UMBs but HIMEM type drivers generally have never provided UMBs, those are usually provided only by EMMs like EMM386. –

Telling EMM386 to reserve some memory space for the enabler, with a line in your CONFIG.SYS like: DEVICE=C:\EMM386.EXE NOEMS X=D000-D3FF. Running the enabler when you boot the computer by adding a line to your AUTOEXEC.BAT; If you intend to use different PCMCIA cards, and hot-swap between them, you may want to look at the contents of the PCMCIA ...

2023年1月23日 · The EMM386 mainly handles the memory mapping to provide rest of the memory as EMM to the virtual 86 mode task. If you don't use EMM386 or similar manager, but only use HIMEM or similar memory manager to provide XMS, it will also switch the CPU to protected mode momentarily to allow for copying conventional memory to XMS or back, but …

2018年6月21日 · the memory manager: HIMEM.SYS only (for games which wouldn’t work with a V86 memory manager), EMM386.EXE with or without EMS (without EMS, you’d get 64K more UMBs) the amount of resources assigned to FILES , BUFFERS etc. (you’d need more for a multi-tasking environment; this could be what your friend’s “Windows” configuration changed)

2019年11月5日 · EMM386 supports a different range of interrupts etc, that Lotus, Intel and Microsoft agreed on. Like HIMEM, there are programs that support this, and it involves a bit of poking around in RAM. Windows only uses HIMEM.SYS 2.77 on the DOS side, and VMM.vxd looks after memory on the windows side.