The RP04 is the first PDP11 Massbus disk; it uses the
RH11 (or RH70
for 11/70s) controller. It's 88 MB (half of the RP06).
Right! That was the one which slipped my mind too. Definitely on the list
of interesting controllers to emulate.
Speaking of block access devices -- for supporting old
OSs, a TC11
emulator might be helpful... :-)
I had considered a TC11, but I'm not sure of the benefits other than
it just being interesting...
--tom