Disc Writer G284

This document is a technical schematic for the Digital Equipment Corporation "Disc Writer G284" circuit board, dated January 26, 1967.

The circuit diagram illustrates a symmetrical design intended for test and maintenance purposes. It features:

• Input and Output sections: Two primary input channels (labeled E, F, H and S, T, U) and an "Out to Head" connection.
• Active Components: The design utilizes four transistors (two DEC 1008 and two DEC 6534B) along with six additional transistors (two DEC 3009B) and an array of diodes (D664 and D662).
• Passive Components: A variety of resistors and capacitors are configured to facilitate the operation of the circuit across voltage rails of +10V, ground, and -15V.
• Conversion Chart: A reference table is included at the bottom, cross-referencing DEC internal part numbers (e.g., DEC1008, DEC6534B) with standard industry EIA part numbers (e.g., MM1008, 2N3009).

The schematic notes that unless otherwise specified, all diodes are D662 and all resistors are 1/4W with a 5% tolerance.