Debugging ONMIBUS cards

OK... take two on this... I've been working with a pile of hex and quad ONMIBUS cards and a PDP-8/e and PDP-8/a chassis. At one point I had a working machine, but since last weekend, something new has flaked out. I have one KK8E board set that passes basic front panel ops, runs an inchworm program but does not seem to be able to communicate out the serial port (M8560). I have a KK8A/DKC8AA/KM8A set that appears to boot floppies, but gives me funny results on the console. The KK8E processor board set does not seem to want to work in the -8/a box. The KK8A does not seem to work in the PDP-8/e box (the Load Address switch increments the MA register; it doesn't load it). The best I'm getting out of the -8/a right now is to waggle the floppies a bit, sort of boot, and drop me at an OS/8 dot prompt. This is even true of the ADVENTURE floppy that was booting last week. When I type commands at the prompt, none run, but I get odd error messages. One pattern is that if I type the command "ADVENT" at the prompt on the advent disk, I get back "ADFEND" - the letters drop a bit. If I attempt to run a command "UUUU", I get back "EEEE" as an error. Given that if the CPU or memory or RX8E were bad the system wouldn't boot, it suggests to me that there is a problem with the DKC8AA. My biggest problem is that I have schematics, but without a front panel on the PDP-8/a, I can't generate discreet operations to run the CPU through its paces and I can't toggle in simple programs. I have the prints for the DKC8AA. Is it feasible to build my own front panel? I don't even have one to copy; I'd be guessing the whole way. If I could use the KK8A in the -8/e box, I would use _its_ front panel, but that doesn't seem to work either. Does anyone have any helpful advice to get me past this chicken and the egg problem? I have prints; I have extender cards; I have a scope. I even have a logic analyzer, but it's not presently at the same place as the -8's. What I don't have is a combination of PDP-8 hardware that lends itself to reasonable testing. As for the PDP-8/e, does anyone have a simple TTY test routine? I could write one, but I'd love to see one that has stood the test of time. As I mentioned above, the inchworm runs fine. I'm presently using all quad cards except for an MS8-C 32K MOS memory card; I have core, but I don't know where the box of overhead connectors got left - I only know where three connectors are and the CPU needs two. I do happen to have a couple of Heathkit backplane connectors I can wire together, but I'm still short enough to do a proper job. For now, the MOS memory seems to work fine; it's the M865 and M8650 that I'm looking into. Thanks in advance, -ethan ===== Infinet has been sold. The domain is going away in February. Please send all replies to erd(a)iname.com __________________________________________________ Do You Yahoo!? Thousands of Stores. Millions of Products. All in one place. Yahoo! Shopping.