Best approach for debugging a Win 16-bit application?

Question

I must reverse a legacy windows (16-bit, NE exec) application that controls an old DAQ that I must interface somehow with upgraded hardware. I've been able to disassemble the exec using W32Dasm (and WindowsCodeBack as well, the only two from many that I've tried that have worked) but the resulting asm file contains too many lines. I'd like to use a debugger and set some breakpoints to restrict the work. Could you advise which is the right approach to debug a Win16 app in 32-bit times? A VM running Windows98 for example? Which Win16 debugger could I use?

Many thanks

Stereometry

Answer 1

IDA can disassemble Win16 programs as well (though not the free version), and it's much more convenient than plain dead listing.

As for debuggers, I would try to find the Win16 Turbo Debugger (TDW.EXE). There's also OpenWatcom, which even supports remote debugging (so you can run the program in a VM and the debugger UI on your desktop).

Snoopy

I've already started debugging using OpenWatcom. I had tried it before but I chose the wrong debugger and I couldn't do anything. I may try TWD tomorrow. Thanks a million :-) – Stereometry

@Stereometry so IDA doesn't support debugging 16-bit applications? – Rashidarashidi