G217

This document is a proprietary schematic diagram for the Digital Equipment Corporation (DEC) "Memory Word Driver G217," copyrighted 1968.

The circuit is designed for driving word lines in a memory system. It features two primary rows of driver circuits (labeled 'AR' and 'BR' at the top and bottom respectively), each containing multiple, nearly identical sub-circuits. Each sub-circuit utilizes a transistor (e.g., MM999) coupled with a multi-winding transformer (e.g., T-2071) to generate output signals, with inputs fed through arrays of diodes.

The schematic provides general specifications for components, indicating that transformers are T-2071, transistors are DECIOII, most resistors are 1/4W 5%, and diodes are D-664. A conversion chart for DEC transistor and diode part numbers to EIA equivalents is also included.

Key points from the document:

• Purpose: Memory Word Driver G217.
• Manufacturer: Digital Equipment Corporation (DEC).
• Date: Copyright 1968.
• Usage: Furnished only for test and maintenance purposes; circuits are proprietary.
• Components: Primarily uses transistors (DECIOII/MM999) and transformers (T-2071), along with diodes (D-664) and resistors (1/4W, 5% or 10%).
• Structure: Two main driver lines (AR and BR), each composed of multiple identical transistor-transformer stages.
• Ancillary: References a parts list (A-PL-G217-0-0) and suggests using the G209 etch board.