On the topic of ROMs: It seems like there are different ROM versions for
the 5620, one working with the blit code in v8 (I had a real one
hooked up to my laptop running v8 under simh) and the other not.
Unfortunately it seems that the compatible ROMs have not been dumped yet
so the simh-based 5620 emulator that has been around for a while now
does not work with the v8 blit stuff.

It would be cool if a 5620 owner could dump their ROM or the existing
version could be patched.

aap