IO Bus Driver M664

This document contains the engineering schematic for the M664 IO Bus Driver module, produced by Digital Equipment Corporation in 1971. It provides a detailed circuit layout, including transistors, diodes, and integrated circuits (DEC 74H00 logic). The document also includes a parts list, hardware specifications (resistor, diode, capacitor, and transistor types), and a transistor/diode conversion chart for maintenance and testing purposes.