Inverter B104

This document is an electronic schematic diagram for the Digital Equipment Corporation (DEC) INVERTER BIO4, specifically part number BI04-0-1, copyrighted in 1964.

Key features and information include:

• Proprietary Nature: A disclaimer states the schematic is proprietary, for test and maintenance purposes only, and copyrighted by DEC.
• Circuit Design: The core circuit features four identical transistor-based inverter stages (Q1-Q4), each with input resistors and a capacitor. These stages are fed by diode-resistor input networks (D1-D3, R3, R4, R6).
• Power and Regulation: A dedicated "-3V STRATE" section provides a regulated -3V supply or reference using a resistor (R7) and four diodes (D4-D7). The entire circuit is powered by OB-15V, -3V, and ground (OC GND) lines.
• Component Specifications: General component specifications indicate that resistors are 1/4W, 10% (unless otherwise noted), and capacitors are in MMFD.
• Conversion Chart: A "Transistor & Diode Conversion Chart" provides DEC part numbers and their EIA equivalents for transistors (DEC2894-1) and diodes (D662, D664).
• Revisions and Authorship: The document includes revision history and lists personnel involved in its creation and checking, along with dates in April/May 1964.