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Is there a DOS memory documentation available? (Users)

posted by Zyzzle, 10.01.2024, 04:47

> c) A command has a short documentation that explains the most important
> effects and you can simply overtake it. GREAT!
 OK, one command which has too short documentation in FreeDOS is in the SWITCHES syntax, specifically the /E switch. Apparently it does this:
/E enables moving of EBDA (Extended BIOS Data Area), optionally a size in kilobytes may be specified [xxx, in range of 48-1024]

Now, I have multiple newish laptops which only report ~625kb of total low (640kb memory) due to code which is in the EDBA. Nothing I've been able to do will get dos to report "655360 (640K) of total memory" because of the commandeering of the EDBA code which takes low memory, before anything else is apparently even loaded - including the DOS kernel itself.

So, my question is will using the /E switch somehow move that code out of low memory and into upper memory? XMS memory? Or what will it do, exactly.

I've also read conflicting reports that say the /E switch does the opposite of what I think it might do, that is, *disable* the kernel from moving EBDA BIOS code into upper memory / UMB / XMS. Others have claimed the /E switch is "broken" and has no effect on most systems. Further, why does MS-DOS have no such (equivalent) option?

And lastly, why can't memory ranges of less than 48 kb be specified for the switch. In my case, 32 kb, or even 16kb would be sufficient to reclaim my "lost" low memory taken by the BIOS code.

And, I do appreciate all the time you've spent on creating this documentation.

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