Forget about AFD?
Seriously, you *could* find yourself a debugger written this century. AFD is pretty old. Well... I'm pretty old, too, but I ain't dead yet! If you want to use AFD, you should be able to.
We know that AFD doesn't like Nasm's .map files. That isn't too much of a surprise, they weren't intended to be "standard" (AFAIK). We don't know (*I* don't) what AFD *does* like.
In my old /dos directory, I've got a few .map files. Mostly Nasm's .map files, which we know aren't suitable. The remainder, made with "who knows" what linker, mostly just list "segments". Some have error messages about "undefined symbol" in 'em. Some are from Windows files, and speak of "IMPORTS", which I don't think will help us. The few that might help seem to be of the form:
SEGMENT code PUBLIC USE16 BYTE ''
at 00000000, length 0000000A
publics:
_K_main at code:00000000
(made by Alink, which isn't that old) As a flying wild-asmed experiment, you might try creating, by hand, a "danish.map" file like:
SEGMENT .text PUBLIC USE16 BYTE ''
at 00000000, length 0000001F
publics:
num1 at .text:00000117
num2 at .text:00000119
num3 at .text:0000011B
num1 at .text:0000011D
Feed that to AFD and see what it says. Probably won't work, but if it does, we can think about writing a utility to convert Nasm's idea of a .map file into "something like that". Won't be pretty, but we can probably do something that works. Could modify the Nasm code, too, but I'd rather not go that route! (to please a twenty-year-old debugger? naw...)
Disassembling ("reverse engineering") AFD to see what it's looking for is a possibility, too. That would be tedious, and probably illegal. I don't care about "legal"* - they'll never take me alive! - but "tedious" doesn't appeal to me. "Trial and error" is probably easier...
When I was running dos, I liked David Lindauer's GRDB - like DEBUG, only with a brain. That will accept a ".sym" file. The feature was added after I stopped using dos, so I don't know what the format of the ".sym" file is, either, but we have source code for that, so a "converter" would probably be easier - and probably more useful, too. If you're forced to give up on AFD, we can look into that...
But if you're stubborn enough, we can probably get this to work. Whether it's "worthwhile" or not is another question. If I have occasion to reboot to dos, I'll have a look at it, but meanwhile, see what you can figure out on your own. Doing it as an .exe file rather than a .com file might be the simplest thing...
Best,
Frank
* Don't post anything illegal *here* though!