This document is made up of information extracted from the LSI-11 Processor Handbook and PDP-11 Architecture Handbook. It defines the basic instruction set and addressing modes of the Digital Equipment Corporation (DEC) generic PDP-11 family of minicomputers. The information acts as a processor handbook in support of the PDP-11 Simulator System that defines an assembly language and simulator based upon the DEC PDP-11/60, developed in the Dept. of Computer Science in 1996-97. A PDP-11 Simulator System Manual may be purchased from the Department office (MS 247).