Thanks! I wouldn't even have guessed where to look.
In the meantime helwie is sussing out the keyboard matrix, I dumped and revitalised my P30 and will post about it tomorrow, and jlopezm is attempting to dump a complete set from his unique Spanish machine.

Robert

NCR DMV- DEC Rainbow- Siemens PCD- ITT 3030-Oly People- Acorn A5000- Olivetti M20