MF10 Core Memory

This document serves as a maintenance manual for the DECsystem-10 MF10 Core Memory, providing a comprehensive guide to its general information, installation, operation, principles, and maintenance procedures.

The MF10 is a 3D, 3-wire, coincident current, ferrite core memory capable of storing up to 65,536 37-bit words (36 data bits plus 1 parity bit) with a cycle time of 950 ns. It is designed for asynchronous operation within the PDP-10 system, featuring up to four access ports and supporting 2-way or 4-way interleaving for improved performance. The memory unit is physically housed in a standard PDP-10 cabinet and is divided into two major logic sections: the Port Control and Core Interface (PCCI) and the Core Memory and Control (CMC).

The manual details installation procedures, including site preparation, cabling, and configuring various jumpers and switches for module size, memory address, and interleaving. It then describes the operational aspects of the MF10 through its five control and indicator panels (Power Control, Memory Address Switch, Maintenance, Margin Switch, and Indicator Panel), which facilitate fault detection, checkout, and troubleshooting.

A significant portion of the document covers the principles of operation, explaining memory cycle timing (Read/Restore, Clear/Write, Read/Modify/Write), the request/acknowledge system with priority logic for simultaneous access requests, and a detailed description of the core array, addressing mechanisms, read/write current generation, and sensing. It also provides an overview of the MF10's power system, including the 857 Power Control, 783C Power Supplies, and H742A Power Supply with its regulators.

Finally, the maintenance chapter outlines both preventive and corrective maintenance tasks. Preventive maintenance includes daily visual inspections, monthly and semiannual diagnostic runs, and margin checks using specific switch settings. Corrective maintenance provides troubleshooting procedures, including procedural aids, diagnostic error interpretation, and detailed steps for MF10-M module replacement, power system maintenance, and voltage regulator testing.