From: Noel Chiappa
There's documentation somewhere (don't recall
off the top of my head
..) about how to configure the Aux switch.
Remembered where I saw it: in the "PDP-11/23B Mounting Box User's Guide"
(EK-23BMB-UG-001), available here:
http://www.computer.museum.uq.edu.au/pdf/EK-23BMB-UG-001%20PDP-11-23B%20Mou…
among many other places, on pp. 2-3 and 2-4. (This manual talks about the
BA11-S, but the front panel configuration is the same for other boxes - my
BA11-N has the exact same hardware on the front panel.)
Noel