On Jun 30, 2016 1:19 AM, "Fritz Mueller" <fritzm at fritzm.org> wrote: and/or assembled boards at http://www.shiresoft.com/products/km11/KM11%20Replica.html. I built one up myself based on a layout by Tom Uban at http://www.ubanproductions.com/museum.html short, repro case would be to step through the microcode with a KM11 and see where it goes awry. From that point, its fairly easy to come of up a list of boards to swap and/or chips to check. extenders and a logic probe, they are pretty cheap. Or you can grab a surplus logic analyzer and some DIP clips off eBay if you want to get posh! Fritz, It turns out that I was missing the KJ11 my cpu cards were wired to expect. On the 11/40 this module is the little M7237 card for space E of slot 3. The machine in question did not come with this card, I assumed it was not needed until I checked the cpu jumpers and discovered my error. Should have done this 1st! It was impossible to run the CQKC diagnostic for 11/40 or 11/45 - http://www.vintagecomputer.net/temp/disassembly.txt Instructions using IOT in particular. Bill Degnan twitter: billdeg vintagecomputer.net