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

Function of the card:
SDTDL two 5-way n and logic blocks without. loads
SDTDL two 5-way n and logic blocks without loads

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

Part number: 370221

PCB number: 399589 , hole pattern: 399402

Used in: IBM 1311 Disk, IBM 1410


+O: Positive OR. In-phase output is positive if one or more input signals are positive. Out-of phase output is negative for the above condition.

References: 1410_SMS_VOL_1.pdf, p38
IBM 1311 ILD, p114
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.