I will dig up my notes getting characters in and out a M7800 in my 11/35 resurrection using the front panel several years ago. This is also an advice: make notes of *everything* you do on a system, no matter how trivial at this time. Changing a wire, trying some toggle in tests on the console, behaviour, measured voltages on pins, etc. If problems occur later you can go back and do all tests from your notes. That's why I can write my tests with the M7800 when I get home (in a few hours from now). - Henk, PA8PDP.