I took the csh550.lha from Aminet as advised, and I can compile it with SAS/C with no changes. The resulting binary (68k) runs on the 4000/OS4 68k and on the A1/OS4 PPC in emulation.

The only problem that I can see is that the shell does not print its prompt to the screen. All output from the shell (like error messages and built-in commands) seems to work OK (both platforms).

This shell does not use ixemul and I can not find any reference to "fork". As it stands, it needs Amiga-like paths (it can't understand /ram/filename).

I'll update the wiki as soon as I get the prompt to work. I'll also try compiling it with gcc (haven't used gcc on the A1 yet, so a new adventure).

cheers