lee.gleason at comcast.net wrote: I remember poring over the drawings for the RB730 at the time, wondering if a plain non-DEC SMD drive would have worked .... Yeah - I was wondering the same thing. The RM80 Technical Manual doesn't seem to be online, but the RM MASSBUS Adapter Technical Manual http://bitsavers.trailing-edge.com/www.computer.museum.uq.edu.au/pdf/EK-RMA… has a lot of information about the RM80 too. It looks like the RM80 used the same MASSBUS Drive Control Logic box as the RM0x drives. As I remember, the RM02/3/5 were CDC 9760-something drives, which were SMD. Of course it's possible that the DEC OEM versions had customized interfaces. The RB730 Technical Manual is also online http://bitsavers.trailing-edge.com/pdf/dec/vax/730/EK-RB730-TD-001_VAX-11_7… and it has a description of the R80 interface, but this version doesn't look that much like SMD to me. Bb