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

Function of the card:
High Current Indicator Driver
Alloy-Indicator Driver 40 mA
Alloy - indicator driver 40 ma

Listed in 1401 SMS card usage

Germanium alloy transistors were an early type of transistor, faster than the earlier grown-junction transistors.

Part number: 371546

Used in: IBM 1410, IBM 1401, IBM 7070

Cap code: None (details)

Symbol: DI

DI: Driver, Indicator. Driver operating into an indicating device.
IBM SMS card type KA 371546 IBM SMS card type KA 371546 IBM SMS card type KA 371546 IBM SMS card type KA 371546

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: 2_2 SMS Cards, p41
IBM Standard Modular System, Component Circuits, p166
1410_SMS_VOL_2.pdf, p91
Coslet data

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.