Well, that's great! If you manage to dump the PIO I'm surely interested.
I just uploaded my improved MDS-II emulator to the MAME/MESS project. In
this version of the emulator the PIO runs a firmware that I wrote a few
days ago (and that I assembled on the emulated MDS-II with the original
ASM-48, of course!). At the moment my version of PIO just supports the
printer output.
-- F.Ulivi