Variable Clock M452

This document contains the engineering schematics and component layout for the Digital Equipment Corporation "Variable Clock M452" module, dated April 1967.

Summary:

• Schematic: The document provides the detailed circuit diagram for the M452, utilizing integrated circuits (DEC7440N, DEC7474N, and DEC7400N), various transistors (DEC3009B, DEC6534B), and associated resistors, capacitors, and diodes. It highlights the power requirements (Pin 7 as Ground, Pin 14 as +5V) and provides a transistor and diode conversion chart.
• Layout: A board component map is included, showing the physical placement of the transistors (Q1-Q4), integrated circuits (E1-E3), and passive components on the M452 circuit board.
• Note: The documentation specifies that it is for test and maintenance purposes and contains proprietary circuit designs.