PDP-11/40 Processor Handbook

This document is a technical reference manual for the Digital Equipment Corporation (DEC) PDP-11/40, a 16-bit, general-purpose computer. It details the architecture of the machine, including the UNIBUS system, the central processor's general registers, the instruction set, and various addressing modes. The handbook also covers essential programming techniques such as stack management, subroutine linkage, interrupt handling, reentrancy, and position-independent code (PIC). Furthermore, it describes the optional memory management unit, internal processor options like the Extended Instruction Set (EIS) and the Floating Point Unit, console operations, and complete system specifications and instruction timings.