Function of the card:
Free Running Crystal Oscillator (500KC)
Part number: 371456
IBM Standard Modular System, Component Circuits, pp216,217
The information on these pages comes from a variety of sources, especially old IBM documents on bitsavers.org, as well as information from the IBM 1401 restoration team, especially Tim Coslet's SMS data and Jim Hunt's data. Much of this information was obtained through OCR, so don't expect complete accuracy. These pages are not associated with IBM in any way.