SHARE |
|
by Bill Degnan - 05/24/2016 19:57 | |
copy of CCTECH email
There have been a lot of parallel discussions on my PDP 11/40, I am consolidating them all here: I now have 5 backplanes installed. Here they are, described in order. I walked through this will Paul Anderson last night (thanks Paul!) to verify everything was in the right place and in the right order, in the right power, etc. The +5V is a little weak but I can tweak it, etc. 1. CPU backplane. This is the same backplane I have had running/working for 10 years. There is no M2737 or M787 installed, just a stock CPU card set. No changes have been made. 2. core backplane #1 32k x 16 - 18 Memory backplane 500344C. This backplane has one set of core cards installed in the order they came from another system. These are electrically ok, but not tested/known to pass memory tests. The M8293 is set to 0000 9/11: M981 (1-2) 11: M8293 (3-6) 12: M7259 (1-2) 13: G114 14: H217C 15: G235 The 2nd half of the 1st core backplane is empty. Photo of CPU and 16K Core installed 3. The 2nd core backplane is empty. There are M920's on either end to connect them 4. The next backplane is a DD11B. This is empty other than grant cards in each slot D. An M9202 connects the DD11B to the next backplane 5. The final (5th) backplane is a DD11C In the first slot (closest to the front) GC in slot 4. In the 2nd there is a M7261 RT11 drive controller. This slot requires a NPG G7273 installed if not in use, the M7761 requires this kind of slot. It's not hooked up to anything (RL02). In the 3rd slot is a GC card In the 4th slot I switched back and forth between the terminated M9312 and M930 terminator. In 3 and 4 I have a G7273. The G7273 is required because previously the NPG was removed from wirewrap, this backplane is no longer "stock" because both the 4th and 2nd require NPG. Ultimately I decided to remove the M9312 terminator/ROM card, and I am using a M930 terminator instead. I also experimented with the MOS RAM in slot 3 but I decided I don't want it installed for now. Only the drive controller and grant cards/terminator remain at the moment. WHEN I POWER UP - I have full console access, everything "works" and now I have 16K of core. I can save and run "chase the lights" at any point within the 16K. I have spare core cards to draw upon, I had pulled a good set for my 11/05 I could always use those if need be. Thanks everyone for your help and suggestions. NEXT: Double-check power, especially to the rear DD11C backplane. That might explain why I can't boot off the M9312 anymore. I also want to see what I can safely put into the DD11-B backplane, such as the M7856 serial card. Reply |