Function of the card:
SDTRL mup number 20
3/3 Input Open Collector AND/OR w/ Pulldown, Inverter
Part number: 370228
PCB number: 484047 , hole pattern: 493457
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.