Hi First thanks to all for considerable assistance. I can now talk to the RX 211 on the Unibus. First it did need the NPR jumper removing. Secondly I made the system into an 11/84 (Processor in slot 1 nothing in 2 MSV11-J in 3 ) Finally I'm so used to hex modules in Unibus and the RX 211 is a quad. Of course it needs to go in CDEF. Switch on finds PMI memory ok counts up to 9 as normal. Asks for choice. Type in B DY0 and we get a nice error message with lots of parameters. Time to become a 94 again. Bonus: The other 94 chassis can become a 84 I have enough parts. Rod