12 Bit 16 Word Memory M253

This document is a technical schematic for a 12-bit, 16-word memory module (part number M253-0-1) produced by the Digital Equipment Corporation.

Summary:

• Circuitry: The schematic details the wiring logic for three DEC7489 memory chips (E1, E2, and E3) and one DEC1074H00 logic chip (E4). It illustrates the interconnections for address inputs, data inputs, and data outputs.
• Components: The document includes a bill of materials listing necessary components, such as integrated circuits, resistors, capacitors, the etched circuit board, and a handle.
• Specifications: It notes standard operating conditions, including the use of +5V power and ground connections, as well as specific values for resistors (330Ω, 750Ω) and capacitors (0.01μF, 68μF).
• Layout: The document provides a top-down view of the circuit board layout, indicating the physical placement of the E1, E2, E3, and E4 chips and relevant capacitors.