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

Function of the card:
SDTRL - 1.33 mc crystal oscillator

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

Part number: 370259

PCB number: 493345

Used in: IBM 1410

IBM SMS card type TCV 370259 IBM SMS card type TCV 370259

Image courtesy of Henk Stegeman

References: 1410_SMS_VOL_1.pdf, p72
This page created by Ken Shirriff on Wed Sep 15 18:15:10 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.