The decoding of the DEC PDP XX2247 keys has been discussed, but I have not yet seen decoding for others.
To repeat the data for XX2247, that is 5173757 assuming 7-1 with a center offset To add to that knowledge, I'm checking other keys I have. Note - I'm sure of the XX values of course but the codes have not been tested/confirmed yet; I will do so and report back. For every Data General Nova (800, 1200, 1220, 2) & Eclipse (S/130, S/200) that I have, those keys are all stamped XX2065. The coding appears to be 1353757 (7-1, center offset) For every HP 2100 that I have, those keys are all stamped XX2946. The coding appears to be 4557457 (7-1, center offset). Of course, the advantage is that copies of copies tend to get off, and with the original code we can all get "original tolerance" keys. While I'm testing/confirming the codes for XX2065 and XX2946, can anyone with stamped DG Nova/Eclipse keys or stamped HP2100 keys confirm if their XX numbers are all the same? I've got enough of each that I'm fairly sure those keys fit all of those systems, but wanted to check. Are there other common systems that used Ace keys that we should document besides XX2247, XX2065, and XX2946? I should probably toss up a quick website under classiccmp if so. J