Someone knows how to use all RAM under DOS?It's so hard,at least for me.Please tell me if you have any idea.Thank you.

there are 4 common ways
- XMS, through himem.sys driver, installed nearly always, allows you to allocate memory above 1mb and copy it below 1mb (and back)
- EMS, through emm386, maps memory into space addresable below 1mb.
- flat-real mode, where you just make whole memory addressable, but doesnt work when EMS manager (such as emm386) is installed. This way is used by FASM too.
- protected mode - nice way again, you have to get some protected mode manager (someone could aid some good PM manager, i dont have picture about these). You can have valid 32bit code running in 32bit memory area.

i personally suggest you flat-real mode, i used it even in turbo pascal, only problem is you have to make user remove emm386 from config.sys.

If you are instered in some of these ways, let me know. I have docs on all of them on my old 486, i can post them.

Take a look at the Fasm source to see how you can enter into flat real mode.

Regards Mac2004

if U use FASM in native DOS (no other mem-managers) there is no need to do anything, just program 32bit and run.

FASM do it for you!
mean can address all ram in your mainboard!

HarryTurtle: This way predicts you run fasm before executing executable. But anyone else using program created this way will probably get GPF because he didn't run fasm before.

privalov: DOS version of FASM doesn't restore from unreal mode on exit (setting segment limit to 64k etc.) ?!?

The same does the HIMEM.SYS, which also uses the FRM. It is harmless.

of course, but people like HarryTurtle (no harm) may get fooled by this and maybe even think fasm adds code which switchs to frm or whatever. Yes, it's allright, but i just like cleaning all my mess done (even if it isn't mess

Well!!
This DOES interest me!!!!
OK, vid:
If you have any tutorials, it would be indeed very nice if you could post them:
What I am mainly interested in are the three first ways, especially that "flat real-mode" thing and himem.sys!!
Actually, I have a 486-DOS machine with himem.sys, and really would like to use it to the full ... which here is 8MB ram *wooow*

If you want other people than you to use the program, without having to modify system setup, you have a long journey ahead of you .

The easiest would be to use an existing dos extender, like WDOSX ( http://michael.tippach.bei.t-online.de/wdosx/ ). There's probably better DOS extenders out by now, but WDOSX works fine - it comes with source, so you could learn a few tricks from there.

Thanx man!!!
That page is wonderful, and one of the links is remarkable:
http://www.thefreecountry.com/compilers/index.shtml

This is a list with who-knows-how-many compilers & Co for who knows what types of languages!!
(This is for all that read it & don't know the page)

For most compatibility, use the XMS v3.0+ standard to allocate up to 4Gb of memory. This way your program will not overwrite other's memory.

It's all in Ralf Brown's interrupt list.