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

Function of the card:
SDTRL - 3 way inverter number 2
SDTRL-3 way inverter number 2
SDTRL - 3 Way Inverter Number 2

Listed in 1401 SMS card usage

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

Part number: 371951

PCB number: 492909 , hole pattern: 491329

Used in: IBM 729V, IBM 1410, IBM 1414 I/O Synchronizer

IBM SMS card type DAC 371951 IBM SMS card type DAC 371951

References: National Museum of Computing.
1410_SMS_VOL_2.pdf, p121
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.