Finally, I've typed out the DIO bus pinout from that HP9826/9836 Pascal
system manual that's on bitsavers (this being the piece of info that's
going to be the most useful to me at the momnent).
--
http://www.blobulent.com:16080/hp300/peripherals/
have a few interesting scans, like the schematic for the
98625A SCSI interface.