mmm... let me state this clearly before I get misunderstood: if someone else shows up today with a brand new implementation which does not break anything and adds the missing features, I would have no problem to throw everything away.

is this likely to happen? no (among other reasons, people interested in fixing the MESS code are already working on it wink )

if it would depend only on me, otoh, I would simply try to rewrite the more deeper level of the rendering to directly handle pixel positions (not sure how to do it with the current code) since it is needed by OPT.

my first attempt went bad, and I'm currently a bit more interested in NES than SNES. but I'll try again as soon as I have enough spare time to spend on it smile