R202

This document is a proprietary schematic diagram for a Dual Flip Flop, Model R202, copyrighted by Digital Equipment Corporation in 1964.

The schematic is intended for test and maintenance purposes and details two flip-flop circuits, each using DEC 3639C transistors (Q1/Q2 and Q3/Q4) along with numerous diodes (D-662 series frequently indicated, with a general note of D-664), resistors, and capacitors.

Key information provided includes:

• A Transistor & Diode Conversion Chart listing EIA equivalents for DEC parts (e.g., DEC 3639C to 2N3639, D662 to IN645, D664 to IN3606).
• General component specifications: Resistors are 1/4W, 5%; capacitors are MMFD; diodes are generally D-664.
• Power connections for +10V (OA+10V), Ground (OC GND), and -15V (OB-15V).
• Revision F, along with design, check, and engineering dates from June 1964.