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

Function of the card:
SDTDL modified double level logic block number 1

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

Part number: 370265

PCB number: 484091

Used in: IBM 1410

Cap code: None (details)

References: 1410_SMS_VOL_1.pdf, p77

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.