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

Function of the card:
Alloy-Memory Thermal Switches

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

Part number: 370425

Field replacement part number: 370425

Customer Eng reference number: 729806

PCB number: 484157

Used in: IBM 1401


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

1_2 SMS Cards, p63.
This page created by Ken Shirriff.

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.