There are print sets (aka Schematics) for all of the DEC PDP-11 systems, however, as one of, if not the, most popular minicomputer architecture there is isn't any "single" set of schematics. You have to realize that PDP-11 architecture machines come in three basic varieties: 1) Microcoded CPU systems build out of separate parts: 11/10, 11/20, 11/40, 11/70 etc 2) Some Integration (Unibus) 11/04, 11/24, 11/34, 11/44 3) High Integration (usually Q-bus) 11/03, 11/23, 11/73, 11/83, 11/93 And some more specialized models 11/45, 11/55 If you just want to know how PDP-11's work, I reccomend the PDP-11 Architecture handbook published by Digitial Equipment Corporation (nee Compaq Computer). If you have a particular PDP-11 model that needs schematics then you need to say what the model number is, and if you have a PDP-11 with lights and switches and no model number, then it is one of the "original" PDP-11's and it was later designated the PDP-11/20. --Chuck At 05:16 PM 7/1/99 -0400, joe comunale wrote: