Try the enhanced DEBUG found here: https://sites.google.com/site/pcdosretro/enhdebug (download link at the bottom). Works just fine in DOSBox without jumping through any hoops, but still fully compatible with DOS's DEBUG.EXE. I'd definitely recommend looking into DOSBox's built-in debugger anyway, …

Okay, I had some more time to tinker around. I'm still very new to x86 assembly (I've got TONS of experience with many other languages, even MIPS assembly, but not x86, lol), so I only vaguely understand the comments. I was able to get the program to work correctly. I had to switch to a different …

Also, if it helps, here is the output I see when unassembling with DOS 3.3 DEBUG.COM. As you can see, it does not look correct. However, looking at the EXE with HxD seems to look correct, or at least more believable than this. -u 2409:0000 0103 ADD [BP+DI],AX 2409:0002 05070B ADD AX,0B07 2409:0005 …

Hey everyone, I've recently taken upon myself to go through some of my really old books and learn x86 assembly...for "fun" :). In any event, I am following the instructions in "Compute!'s Beginner's Guide to Machine Language on the IBM PC and PCjr". Their very first program just swaps some data …