Function of the card:
Twin Card ASM Modem I
Limited Distance Type 2A, Transmitter
Part number: 373807
Image courtesy of Nick Bletsch
References: General FE Handbook
National Museum of Computing.
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.