KW11-P Programmable Real-Time Clock User's Manual (Etch Rev F and up)

This document is a user's manual for the Digital Equipment Corporation (DEC) KW11-P Programmable Real-Time Clock, an optional module for the PDP-11 computer system. Published in August 1976, it describes the KW11-P's function as a means of accurately measuring time intervals and providing programmed real-time interval interrupts and interval counting, which improves computer efficiency.

The KW11-P is a quad-height module (M7228) that operates in various modes, including single-interrupt, repeat-interrupt, and as an external event counter or interval timer. It supports selectable clock rates of 100 kHz, 10 kHz, line frequency (50/60 Hz), and an external clock. The manual details the module's functional units (e.g., Address Control, Interrupt Control, 16-bit Count Set Buffer and Counter, Control and Status Register, Clock and Clock Control) and provides installation instructions, diagnostic information, programming rules, and sample programming examples. It is intended for users familiar with basic digital computer theory and specifically covers KW11-P boards with Etch Revision F and up.