Another newbie DOS reverse enginerer here: I recently used the MEMDUMPBIN command in the DOSBox debugger to get around the obfuscation of a program. Its code was stored in fragments in the binary and placed at the correct positions in memory at runtime. I dumped everything once the de-obfuscation routine was done and then do static analysis with IDA on that memory dump.

Maybe this method would work for you too?

(btw, do you know about the OpenBioforge project? Maybe the person behind it has experience with dealing with the extender)

Thank you, that is a good suggestion. Definitely worth a try.
I am familiar with OpenBioforge. In a sense I could just wait for that to be released since that will likely be way before I have enough done to even resemble a game. But I guess I will just use my own project as a fun learning experience.

Chelnov18 wrote on 2024-01-28, 17:51:

So I was wondering if anyone here has done something similar and could provide some insight into how this is done properly. I am still fairly new to reversing and DOS programming in general, so this may be an obvious question. I am able to see the code running via the DOSBox debugger, so I can do dynamic analysis, but working in IDA would be a big help.

I ran into this issue, too. I don't remember exactly how I solved it, but I am confident that I either used a hex editor to just remove everything before the "extended EXE header" used by Phar Lap (NE? LX?), or the stub-stripping tool supplied with DOS32A was able to do the job.

Chelnov18 wrote on 2024-01-28, 22:26:

Thank you, that is a good suggestion. Definitely worth a try.
I am familiar with OpenBioforge. In a sense I could just wait for that to be released since that will likely be way before I have enough done to even resemble a game. But I guess I will just use my own project as a fun learning experience.

I meant it as maybe the person behind it could help you with questions. I didn't intend it as trying to dissuade you from working on this at all 😀

PharLap's executables is ordinal 32 bit PE files, header starts on 6680h. just select PE loader in IDA when open file for disasm.