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

Function of the card:
Input Output Core Card No. 1

Part number: 371532

Used in: IBM 7070


RDB: Read Buffer Core. Used as card scanning buffer between card reader and central processing unit.

References: IBM Standard Modular System, Component Circuits, pp126,127
This page created by Ken Shirriff on Wed Sep 15 18:15:11 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.