The PDP-11/40 was a high-end 16-bit minicomputer introduced in 1973.
KD11-A-Maintenance.pdf MM11-Core-Memory.pdf PDP11-40-System-Manual.pdf
Part of a presentation to potential customers:
PDP11-40-Handouts-2.pdf
A brochure for DEC's version of Seventh Edition Unix for the PDP-11:
V7M11-Brochure.pdf