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

Function of the card:
Alloy diodes type aas
Alloy-diodes, type aas
Alloy-Diodes, Type AAs

Listed in 1401 SMS card usage

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

Part number: 370564

Customer Eng reference number: 729902

PCB number: 492343

Used in: IBM 1401, IBM 1410, IBM 2821 Control Unit

IBM SMS card type AJT 370564 IBM SMS card type AJT 370564

References: 1410_SMS_VOL_2.pdf, p22
2_2 SMS Cards, p68
Coslet data
IBM 2821 CCD, p19
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.