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

Function of the card:
SDTRL 40 ba inv mesa alloy pwr drvr
SDTRL 40 base inverting mesa alloy power driver

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

Saturated Drift Transistor Resistor Logic (SDTRL) is a form of resistor-transistor logic using faster drift-field transistors.

Part number: 370215

PCB number: 484025 , hole pattern: 493457

Used in: IBM 1414 I/O Synchronizer, IBM 1410

IBM SMS card type AEK 370215 IBM SMS card type AEK 370215

References: 1410_SMS_VOL_1.pdf, p32
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.