MS11-E J MOS Memory User's Manual

This document is the MS11-E-J MOS memory user's manual, published by Digital Equipment Corporation (DEC) in October 1976.

It describes a family of MOS semiconductor random-access memory (RAM) modules (MS11-E through MS11-J) designed for use with PDP-11 Unibus systems. These modules function as slave devices and offer storage capacities from 4K to 16K words, organized in 4K blocks. They support either 16-bit or 18-bit data words, with 18-bit words including two parity bits and requiring an M7850 Parity Control module. Memory can be assigned to adjacent 4K address blocks within the 124K Unibus address space, and a special feature allows assignment of I/O page space for 16K modules in systems without memory management.

Key features of the MS11 MOS memories include:

• Cost-effectiveness and operational advantages over core memory.
• Non-destructive readouts and lower power consumption.
• Volatility (data loss on power-off), but compensated by support for battery-backed power supplies for data retention in a low-power mode.
• Built-in controller logic for periodic data refreshing, which is essential for dynamic MOS devices.

The manual provides detailed installation procedures, covering:

• Verifying factory-installed jumpers according to the memory size.
• Arranging DIP switches to assign the module's Unibus address space and configure for normal operation or I/O page assignment.
• Checking backplane DC voltages (+5V, +15V, -15V, BB+5V) for tolerance.
• Inserting the M7847 module into compatible Unibus backplane slots (e.g., DD11-C, DD11-D, DD11-P).
• Running diagnostic programs to verify proper memory operation after installation.