I want to use GCC 1.x on Windows. You are looking too close at the trees to see the forest. I don’t want GCC 2 or higher, as I want to run the oldest version of GCC I can find to run on Windows 10. EMX 0.9anything is again far too new.

Try to find EMX 0.8a, EMX 0.8b, EMX 0.8c and you’ll see they are impossible to track down.

I’m more interested in seeing if I can get the ancient versions working on modern Windows.

Anyways, AFAIK, EMX is still found (but with old GCC 2.8.1). 0.9d is the last (2001?), supporting up to 1 GB RAM (due to EMS limits??). In DOS, I can use that GCC if I first do “set EMX=c:\utils\rsx.exe” and load CWSDPMI (otherwise it crashes/hangs, too much RAM!).

A quick search shows at least one place to still find EMX:

https://sourceforge.net/projects/emx/files/emx/0.9d-fix04/

RSXNT 1.51 is still found on DJGPP mirrors under /v2tk/ :

http://na.mirror.garr.it/mirrors/djgpp/current/v2tk/rsxdj151.zip

Of course, it’s all moot (because most people stopped caring about binary compatibility). EMX tried to straddle the line between DOS (EMS/VCPI) and OS/2. RSX tried to help it support DPMI (a Win 3.0 invention, as you know, that even OS/2 2.1 supported). Yes, I once or twice used RSXNT to make a dual-mode .EXE for DOS and Win32, but overall it wasn’t well-supported, so it was hit or miss.

Honestly, things like DJGPP v2 (DPMI 0.9 only) “should”, in theory, run on DOS, OS/2, or Win32 (or Linux with DOSEMU, or even DOSBox within limits). But most developers don’t even care enough about that!

So, instead, nowadays you’re expected to recompile for every single target. While not perfect, OpenWatcom does help a lot in that regard.