PDP-11/34A bring up

I am the new keeper of the PDP-11/34A that Jack Rubin rescued a while ago and wrote about here, http://decpicted.blogspot.com/2010/01/pdp-1134a-data-systems-design-dsd-880… I took it on a road trip from Chicago back to St. Paul after VCFMW in September. I've been doing a lot of cleanup on it and finally got to the point where I could power it on (just the CPU box) this weekend. I think now I need to learn about Grant Continuity ;-) There is a M9302 terminator installed in the last slot (left most when looking from the front of the machine) and also an M9312 in slot 4 (amoungst the CPU and cache cards). Two of the original boards are removed from the backplane... the DSD 808830 controller and the DILOG DU130 tape controller. They were in slots 12 and 13. I then also have an RL11 on hand but it is not currently installed in the machine. When I power up the machine, it immediately lights the RUN light on the KY11-B programmer's console. No matter what I do from that console, I cannot get it to exit RUN or print anything to the serial terminal. However, if I remove the M9302 terminator (a trick I found on some web page), then sure enough, I can HALT it, the RUN light goes out and I can do CTRL+BOOT and the serial terminal will spring to life with a register dump and the '@' prompt. I'm pretty sure that my problem is the empty slots 12 and 13 where boards used to be and should now have Grant Continuity cards installed instead... but I am curious why pulling the M9302 makes it "work". What is the mechanism at play there? I also suspect that I may have to look at the backplane wiring for slots 12 and 13 to put back whatever DMA jumpering might have been modified for the two cards that used to be there-- or, at least for one of them as I can probably put the RL11 into one of those slots and it requires DMA. Chris -- Chris Elmquist