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

Function of the card:
Alloy-Memory Thermal Switches

Listed in 1401 SMS card usage

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

Part number: 370425

PCB number: 484157

Used in: IBM 1401

Cap code: None (details)

Symbol: THER

IBM SMS card type AKB 370425 IBM SMS card type AKB 370425 IBM SMS card type AKB 370425 IBM SMS card type AKB 370425

Image courtesy of Göran Axelsson

References: Coslet data
1_2 SMS Cards, p63

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.