This page describes the IBM SMS card "HGC", and is part of the SMS card database.

Function of the card:
Modem II

Limited Distance Type 2A, Receiver

Part number: 373808

IBM SMS card type HGC 373808 IBM SMS card type HGC 373808

Image courtesy of Nick Bletsch
References: General FE Handbook
National Museum of Computing.

This page created by Ken Shirriff on Wed Sep 15 18:15:10 2021.

The information on these pages comes from a variety of sources, especially old IBM documents on, 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.