Michael Devore wrote:
At 04:36 PM 3/13/2005 -0800, root wrote:

Yes, under every version of DOS that I'm aware of, HIMEM.SYS is an XMS driver for 286 and above.

Not true of MS-DOS 7.x.  FreeDOS reports as 7.10, also.
    I was only speaking of MS-DOS  up to 6.22,  because that's what i think of when i talk about DOS. I didn't know there was a DOS 7.x

 Most people that have/had a 386+ just run EMM386 in addition to HIMEM, I'm assuming for the purpose of simulating EMS, especially because many DOS games required EMS specifically.

No, they use it often for VCPI support.  It is also required for UMBs, probably the single most common reason users load EMM386.

    I only meant regular 'Joe User' who uses/used DOS to play games, etc. Not programmers, or DOS experts - I don't know much about UMB (Upper Memory Blocks?) or VCPI. I just remember a friend telling me to use EMM386 because I was getting a 'not enough EMS memory' error when i tried running some old DOS games for the first time.

 I believe M$'s HIMEM.SYS driver simply provided an interface to the BIOS's XMS memory access functions which provided things like GDT's etc. but I don't know all the details.

No, there are no BIOS XMS memory access functions.  There is minimal extended memory support, not XMS.
    The whole XMS topic confuses me. I thought that XMS was extended memory, and that's what I was reffering to. I have just been reading about it, and the book mentioned BIOS routines that provided an offset to a GDT for a PM switch, so I guess I interpreted it wrong.

I found out that FreeDOS's HIMEM.EXE is for 386+ only but i'm not sure why.

The reasons are currently being discussed in freedos-user and freedos-devel.  Given FDXMS286's presence, it is both completely unnecessary and unduly burdensome to the huge majority of non-286 FreeDOS users for HIMEM to back-support 286 machines.

  This was not intended as any sort of criticism on my part. Given that the design goal of FD is to be a clone of MS-DOS, I simply assumed that HIMEM and other components would also be clones of the M$ originals (although I'm sure there are many improvments in the FD versions) - that's why I was surprised to find out that FD HIMEM didn't work on a 286.

    If you read my original message, my 286 was crashing when I used FDXMS286 which is why i was talking about HIMEM/286 issues in the first place. It's not my wish to burden anything/anyone with provisions for 286's.

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