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

Function of the card:
N and P Block Coupling Networks
Alloy coupling netwrks for n&p blcks

Listed in 1401 SMS card usage

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

Part number: 371241

Used in: 7030, IBM 729V, IBM 1414 I/O Synchronizer, IBM 7070, IBM 7090


R: Load. Provides proper terminating impedance or optimum coupling of one circuit to another at the correct operating voltage level.
IBM SMS card type AK 371241 IBM SMS card type AK 371241

References: IBM Standard Modular System, Component Circuits, p29
This page created by Ken Shirriff on Wed Sep 15 18:15:09 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.