1 used for the Apollo Guidance Computer (AGC), which was designed by MIT's Instrumentation Laboratory. There were two versions of this computer built. Block I and Block II2. Block I units used, as a logic element, a single 3-input NOR function, with VCC = 3V, packaged in a TO-47 can. Block II microcircuits, packaged in flat packs as shown in the image below, were dual 3-input NOR functions, with VCC = 4V. Both types of circuits, which use RTL, had a fanout of six.
A study is underway to research the quality and long term reliability of logic
It is planned to report progress of this study here and then formally publish the results.
Block 2 Microcircuits
in flat packs
Equivalent circuit for a Micrologic gate
The circuit operates as follows. When any of the inputs is a logic '1', then the npn transistor is driven into saturation, clamping the output at a logic '0'. If all of the inputs are logic '0's, then all transistors are cutoff and the pullup resistor drives the output to a logic '1'.
Digital Logic and Computer Design
M. Morris Mano
Prentice-Hall, Inc., ©1979
For a summary of older logic technologies: Old_Logic.htm
- AGC NOR Gate Specifications
- AGC Integrated Circuit Packages
- AGC Integrated Circuits and Reliability Page.
Both of our samples passed PIND testing to MIL-STD-883E, Method 2020
Home - NASA Office of Logic Design
Last Revised: February 03, 2010
Digital Engineering Institute
Web Grunt: Richard Katz