Model 8 Add-on Core Memory

This technical manual provides comprehensive information on the Fabri-Tek Model 8/I Add-On Core Memory System. The document is structured into the following sections:

• General Information and Specifications: Overview, memory capacity, cycle characteristics, and system specifications for the 24K word expansion.
• Installation Procedures: Details on CPU modifications, back panel wiring changes, and assembly steps.
• Principles of Operation: Explanations of the Multiplex Assembly, control signals, multiplex data paths, and 3D coincident current core memory operation (read/write cycles).
• Maintenance: Guidelines for troubleshooting control, address, and data-oriented errors, including recommended test equipment and diagnostic patterns (Ones, Zeros, Worst Pattern).
• Replacement Parts List: Detailed tables listing components for the Memory Assembly, Timing and Control Module, and other sub-assemblies.
• Reference Documents: A list of supporting schematics.

Included in the manual are detailed schematics for the Core Array, Memory Electronics, and Timing and Control assemblies, along with specific interface signal configurations for PDP-8/I and PDP-12 systems.