KG09B Memory Extension Control

This document serves as a maintenance manual for the Digital Equipment Corporation PDP-9 computer, specifically detailing the KG09B Memory Extension Control and MM09A/B/C Memory Modules. The KG09B enables the expansion of the PDP-9's core memory from a basic 8192 words up to 32,768 words, utilizing 8192-word MM09 memory modules, each designated as a separate memory bank. It integrates a 2-bit extended program counter (EPC) and a 2-bit extended memory address (EMA) register along with associated control logic.

The manual outlines installation procedures, including physical placement of the KG09B in the ME09B chassis, detailed interface cabling, and power wiring from the PDP-9's main supply and dedicated module power supplies. Operational aspects cover manual controls like the console EXD switch and START key, as well as the ME09B indicator panel for status display. Programming considerations are extensively discussed, introducing four new IOT instructions (SEM, EEM, LEM, EMIR) and explaining how existing instructions like DBR manage and restore the extended memory mode and program context. It also describes how indirect addressing, program jumps, autoindexing, and various interrupt/break conditions (PI, API, DCH/RTC, DMA, and Memory Protection) interact with the multi-bank memory system.

For maintenance, the document provides references to general PDP-9 maintenance practices, lists specific test programs for the memory extension options, and details module replacement, including comprehensive tables of logic modules used in the KG09B and MM09 units. The final chapter includes a complete list of engineering drawings for circuit schematics, block diagrams, and cabling configurations.