Basic Pdp-8, 8/I Memory Checkerboard

This document outlines the diagnostic procedure for testing memory core failures on PDP-8 and PDP-8/I computer systems. Using a "checkerboard" pattern, the program identifies faulty bits in basic 4K memory systems.

The manual provides instructions on loading the program via the RIM loader, choosing between "Low End" or "High End" versions based on the memory range to be tested, and configuring the switch register for specific core unit types. It also details the diagnostic's operational logic—which involves reading, complementing, and verifying memory bits—and explains how to interpret and recover from error halts if a memory location fails to hold the expected 0000 or 7777 values.