M714

This document is a circuit schematic titled "CONTROL FOR CR 81 M714" by Digital Equipment Corporation, copyrighted in 1968. It outlines the digital logic used to control and manage a CR 81 M714 card reader.

The schematic features numerous integrated circuits (labeled E1 through E12), which primarily consist of various DEC74XX series logic gates. Key functional areas indicated by labels include:

• Initialization: "INITIALIZE" signal (NI).
• Reader Status: "READER READY" (R2), "CARD DONE" (E6), "DATA READY" (E6).
• Read Operation: "READ" (S2) and "INDEX MARKERS" (JI, KI).
• Inputs: Various MBx and IOPx signals.
• Outputs: Signals like P1 (6632), R1 (6634), and connections to an "I/O BUS IN INT."

The circuit also incorporates resistors (R1, R2), diodes (D1), and capacitors (C1-C16). Notes specify power connections for the integrated circuits: Pin 7 for Ground (GND) and Pin 14 for +5V.

An accompanying parts list details the specific components by reference designation, description, and part number, including various integrated circuits, resistors, diodes, and capacitors. There is also a transistor and diode conversion chart. The document states that the schematic is for test and maintenance purposes and that the circuits are proprietary.