I've looked into it (as I mentioned in the other linked thread). I was the original author of JPeMu for the PC and for some time co-author of MFME, so the emulation itself is not a problem.
Speed is of course an issue as there is no 6809 ASM core for the gp2x as yet (and I'm no ARM expert), and limited CPU capacity.
Strangely, the video output seems quite sluggish too (in spite of using paeryn's excellent accelerated SDL). I don't have any other choice besides SDL, however, as I would need to be able to test on both PC and GP2X (Linux or Windows, don't really care, although Linux preferred). [and Allegro doesn't really cut it for me].
Finally, the original emulators were written in Borland C++ and made heavy use of the VCL (Visual Component Library) suite. This means that all the GUI stuff was already pretty well handled and simply needed extending to behave like fruit machine components, but I haven't yet come across such a library for SDL, so the prospect is with writing one (which is not a small job).
Theoretically, I have both MPU4 and IMPACT technologies already working (with no sound for the time being), but there's nothing much to see other than a debugger and alpha display to see the code running - they're not actually "playable" as such.
DT
). I've already drawn most of the graphics for it so depending on my mood you may see some WIP shots soon. 
