M103

This document is a schematic diagram for the "DEVICE SELECTOR M103", copyrighted in 1968 by Digital Equipment Corporation. It is explicitly stated that the schematic is for test and maintenance purposes only and contains proprietary circuits.

The circuit design features:

• Integrated Circuits (ICs): Multiple instances of DEC7400N (E4), DEC74H40N (E2, E3, E5), and DEC7430N (E1) are used, suggesting a logic-based function.
• Transistor: One DEC3009B-S (Q1), also listed as 2N3009.
• Diodes: A series of D664 diodes (D1-D16, also listed as 1N3606) are present, primarily at input stages.
• Passive Components: Various resistors (8.2KΩ, 750Ω, 330Ω) and capacitors (.01MFD 100V) are included.
• Inputs/Outputs: The schematic details numerous input lines (e.g., D2-N2, HI, JI, LI, MI, P2, R2, S2) and output lines (e.g., A1-F1, K1, N1), indicating a complex selection or logic processing function.
• Power Supplies: The circuit operates with +5V (A2) and +3V (V1) supplies, with a common ground (C2, T1 GND).

The document also includes a comprehensive parts list, a transistor and diode conversion chart (listing DEC and EIA equivalents), revision history, and detailed drawing information (drawn Oct 1968, engineered Nov 1968).