I've now finished the rebuild of the PSU for my PDP-8/M and have reassembled the chassis and put in a minimal card set consisting of the KK8-E CPU and a 8KW core set. The machine is now semi-operational but I have the following issues left to resolve: 1. Sometimes (generally the first time) when I power the machine on, the RUN light is on and the console is unresponsive to any stimulus (inc halt), although I can cycle the rotary switch to see the various registers/states. Generally if I power cycle, it is fine. Does this indicate power supply instability? I'm guessing the second time I power on, the capacitors are still charged up from the previous powering. 2. Switch 4 doesn't appear to be working (can't set bit 4 for the accumulator or deposits). I've confirmed the switch itself is ok, so think I have a logic problem. Does anyone have schematics for the KC8ML? Thanks, Toby -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.