On Tue, Nov 22, 2016 at 7:48 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu> wrote: Interesting. I'll have to look tonight and see if the same is true for other bus grants -- I can run the system with no grant continuity card at all in slot 9 and everything works. Which seems strange to me. I went through and cleaned the edge connectors on all of the boards, grants, and UNIBUS jumpers, and I went through the CPU set to make sure all jumpers (etc.) are in the right place for running without an MMU, EIS, LTC, Stack Limit, etc. I now have the system booting XXDP (from a SCSI2SD via the SCSI controller) and things are mostly sane. Occasionally the diagnostics start trapping to 10 (reserved instruction trap) so something's amiss but I didn't have time last night to dig into things. I did find out why there was that wire missing on the backplane; the KW11-L requires a wire (carrying one of the bus grant signals) be removed from slot 3. My machine is a bit of a mongrel -- the CPU set that it came with was not original to the machine, so nothing matches up... but things seem to be rectified now. Just need to solve the slot 9 mystery and work on getting diagnostics to pass more reliably. Thanks, Josh