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

Function of the card:
SDTDL-four 2 way n and logic blocks without loads
SDTDL four 2-way n and logic blocks without loads
SDTDL-Four 2-Way N And Logic Blocks without Loads

Listed in 1401 SMS card usage

Saturated Drift Transistor Diode Logic (SDTDL) is a form of Diode-transistor logic using faster drift-field transistors.

Part number: 370217

PCB number: 484027 , hole pattern: 399402

Used in: IBM 1401, IBM 1311 Disk, IBM 1410

Symbol:-A

-A: Negative AND. In-phase output is negative only when all inputs are negative. Out-of-phase output is positive for the above condition.
IBM SMS card type DEG 370217 IBM SMS card type DEG 370217

References: Coslet data
IBM 1311 ILD, p112
1410_SMS_VOL_1.pdf, p34
2_2 SMS Cards, p73
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 bitsavers.org, 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.