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

Function of the card:
SDTRL mup number 9

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

A Multiple-Use Package (MUP) card has circuits jumpered together directly on the card to form more complex circuits.

Part number: 370210

PCB number: 4134015 , hole pattern: 493457

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

IBM SMS card type DEX 370210

Image courtesy of Living Computers Museum+Labs

References: 1410_SMS_VOL_1.pdf, p27
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.