I.O. Bus Reset M666

This document is a technical schematic for the "I.O. Bus Reset M666" circuit, produced by the Digital Equipment Corporation in 1970. The schematic details the electrical configuration of the circuit, including the arrangement of transistors, diodes, resistors, and capacitors. It features two primary signal paths involving pulse transformers (T1 and T2), various integrated circuits (DEC 1074H00), and a matrix of diodes (D5–D30) and resistors. The document also includes a parts list (BOM) specifying the components required for assembly, such as specific flip-chip handles, eyelets, and etched circuit boards, along with a transistor and diode conversion chart.