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

Function of the card:
SDTDL - two 5-way n and logic blocks with loads

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

Part number: 370220

PCB number: 399589 , hole pattern: 399402

Used in: IBM 1410, IBM 1311 Disk

Cap code: None (details)

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.

References: IBM 1311 ILD, p114
1410_SMS_VOL_1.pdf, p37

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.