Yah, the assembly language is going to be a bit of an issue. But I wonder if there wouldn't be some interested parties to turn it all into portable C code ..
You can always compile it to function calls that emulate x86 opcodes. Considering the difference in speed between a 386SX (which ran GEOS acceptably) and a Core i3, it'll probably be fast enough.
Besides, the whole environment can probably run from within the cache of a modern CPU.
That's a neat idea, and probably kind of feasible .. I wonder if anyone will take up the challenge and produce a clean C-portable version .. I'm guessing some of the folks around ContikiOS might be intrigued by this idea. Off to other forums to discuss it further ..
We cross-developed. The host machines were Sun workstations where the dev tools and Swat debugger ran and talked to the PC target (remember that we started with PC/GEOS running on an original IBM PC with 512K of RAM).