I've ported Eric Smith's csim to PalmOS. I've got it emulating the HP-45 and HP-35 (using Peter Monta's extraction of the ROM). Unfortunately the hard disk of the computer i was developing it on died last week so the only version i have is the one on my Treo that emulates the HP-35 only. Does anyone want a copy? I do plan on rewriting it sometime, but i've got to buy a new hard disk and reinstall Linux, etc first.
It's a little slow, but useable. I ported it by simply writing the relevalent Unix calls, which may account for some of the slowness.