I'm sure this is a familiar question to many - does anyone have a list of the two-digit codes displayed on the PDP11-73 during power-up ? I am resurrecting a dormant unit which stops at '1' (I have only the CPU and memory installed in the backplane) I'm not sure if this is a good or a bad code. Any help would be appreciated. Thanks, David Comley Dave, the Error Code 1 = cpu error 1. Make sure that your cpu diag switches are correctly set 2. Make sure your +5vdc and +12vdc power supply is good 3. Make sure your eproms do not have any bent pins J Richardkurtz(a)prodigy.net