Ah, thanks for that. The prints for the boards are available, in the PDP-11/05 Engineering Drawings (on pp. 115-137), but the MF11-L backplane was previously missing. (The -11/05 generally mounts MM11-L sets in the main CPU backplane, so the MF11-L backplane is not included in the -11/05 prints.) It is the non-parity MF11-L backplane (DEC part number 54-09959), not the parity one (part number 54-10331), though. (My theory is that the non-parity version can be upgraded to parity with an etch cut, and some added wires, FWIW.) Noel