Why are you trying to use DEBUG.EXE from DOS?
DOSBOX has its own very good debugger (when it is compiled with debugger support - debugger is not in normal release version).
Search the forum. I think that PRIESTLYBOY's CVS builds have debugger enabled.

As for DOS version changes: you can't (unless you modify sources). DOSBOX reports itself as MS DOS 5.0. But I do not know in what way that debug.exe checks that version.

Mirek

1. Well, I don't know why, but at university our Assambler teacher uses it. He is probably old fashioned. I was just looking through the packages available for my distro and saw DosBox, installed it, & worked out of the box with TASM/TLINK/TD(Turbo Debuger) - I know they're old, but I can't find a better debugger for Linux right now than Turbo Debugger (windows, watches, evaluate/modify etc.) - actually, there might be some IDEs that can do everything but... at the begining, I'll try to emulate best the conditions at the univerisity (I don't have the time, nor the patience to argue with my teacher on assembly language syntax issues).

2. I didn't know that DosBox has a debuger integrated

3. Hmm.. an option to be able to set the emulated dos version in the config file would be nice... I'll have a look. I think the debug.exe I have is from a DOS 7 bootdisk.

P.S. I am a little above a real beginner in assembly language (any hints are welcomed)

dosbox allows to mount hdd images. you can install any dos there.

you can use Turbo debug for debugging or dosbox it's debugger.

you can use hiew for typing assembly
(that's where i type it in)