Function of the card:
Ctrl-sdtrl contact filter card
Ctrl - sdtrl contact filter card and level converter
Part number: 370563
PCB number: 484327
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.