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

Function of the card:
Twin Card ASM Modem I
Modem

Limited Distance Type 2A, Transmitter

Part number: 373807

IBM SMS card type HGB 373807 IBM SMS card type HGB 373807 IBM SMS card type HGB 373807

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 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.