M603

This document is a proprietary schematic diagram for a "PA.MODULE" (Part Number M603-0-1, Revision B), copyrighted 1971 by Digital Equipment Corporation. It is intended for test and maintenance purposes.

The schematic details a complex electronic circuit utilizing:

• Integrated Circuits (ICs): Four types are specified: DEC1074H00 (E1), DEC1074H50 (E2), DEC74H011 (E3), and DEC1074HI1I (E4). All ICs are powered by +5V on Pin 14 and grounded on Pin 7.
• Transistors: Four DEC4258 transistors (Q1-Q4), which cross-reference to EIA 2N4258.
• Diodes: Includes D662 (EIA 1N645) and D664 (EIA 1N3606) types.
• Passive Components: A variety of resistors (typically 1/8W, 1% metal film or 5% carbon film, with values like 1K, 619, 270, 220 ohms) and capacitors (generally 0.01uF 100V 20%, alongside specific 150pF and 39uF types).
• Power Rails: The circuit operates with +5V, +2.8V, and +2.1V power supplies.

The document also includes a comprehensive Parts List specifying quantities for each component (including a handle, eyelets, the etched circuit board, and references to assembly/drilling layouts and X-Y coordinate locations), general component specifications, and a Transistor & Diode Conversion Chart providing EIA equivalents for DEC part numbers. The schematic was drawn by RJ Doucette on March 3, 1971.