Inverter R107

Summary This document is a technical schematic for the Digital Equipment Corporation "Inverter R107" circuit board. The circuit is designed to function as an inverter array, featuring seven parallel transistor stages (Q1–Q7). Each stage utilizes a transistor, a series of diodes (D1–D32), and resistors to process input signals from terminals D, F, J, L, N, R, and T, providing corresponding outputs at terminals E, H, K, M, P, S, and U. The board operates using power supply rails of +10V (A) and -15V (B), with a -3V substrate reference. The diagram also includes a transistor and diode conversion chart and revision history dating back to 1964.