S202

This document is an electronic circuit schematic for the DUAL FLIP-FLOP S202 (part number S202-0-1, Revision D), developed by Digital Equipment Corporation and copyrighted in 1965.

Key information includes:

• Purpose: Furnished solely for test and maintenance purposes, the circuits are proprietary.
• Circuitry: It depicts the detailed wiring and components of a dual flip-flop, including two main transistor pairs (Q1/Q2 and Q3/Q4).

• Component Specifications (unless otherwise indicated):

  • Transistors: DEC 3639C (EIA equivalent: 2N3639)
  • Resistors: Generally 15,000 ohms, 1/4W, 5% tolerance.
  • Capacitors: MMFD (micromicrofarads/picofarads).
  • Diodes: D-664 (EIA equivalent: 1N3606), with some specific diodes noted as D-662 (EIA equivalent: 1N645).

• Power Rails: Indicates connections for A+10V(A), OC GND, and OB-15V.

• Production Note: Advises to "USE THE ETCH BOARD OF THE R202".
• Design Dates: Drawn and checked around June 1965.