Runcga.exe Interface Patch

I have an old-school curiosity project on my hands: tweaking runcga.exe, the executable bundled with 3D Construction Kit 1 (1991, MS-DOS), so its user interface behaves a little differently. I’m not after sweeping modernisations—just a subtle alteration that improves how the program presents or navigates its existing screens while keeping every other feature intact.

Because the code is a 16-bit DOS executable, you’ll probably lean on tools such as IDA, Ghidra, DOSBox, or other disassemblers/debuggers you’re comfortable with. What matters most to me is proven experience reversing or patching legacy binaries; please highlight comparable DOS, Win16, or other low-level UI hacks you’ve done.

Deliverables
• Patched runcga.exe (or a documented binary diff/IPS patch) ready to run under DOSBox and real hardware
• A short write-up explaining the offsets changed, why they were chosen, and how to revert the mod if ever needed

I’ll supply the original executable and can test on my end; you’re welcome to use your own setup as well. Let’s give this classic a gentle facelift!