David pointed out #3 is incorrect. I was thinking of totem-pole drivers, but the drivers in the MFM interface are all open collector. So the usage conflict between RD52 using "drive sel 4" as an output vs. the controller also doing that is not actually a problem at all.
Makes sense: I was able to image an RD50 here, those things are oh so slow but kind of cute. Practically speaking though, it's pretty much a museum piece.
Are you planning on running RSTS/E on the Pro? That would be neat.... C
