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

Function of the card:
SDTDL logic inv. hs wo/load
H.S. logic inverter without load
H.S. Logic Inverter Without Loads

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

Part number: 372593

Customer Eng reference number: 734370

Used in: IBM 2821 Control Unit, IBM 1311 Disk

IBM SMS card type ZGQ 372593 IBM SMS card type ZGQ 372593 IBM SMS card type ZGQ 372593 IBM SMS card type ZGQ 372593

References: National Museum of Computing.
IBM 2821 CCD, p119
IBM 1311 ILD, p153
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.