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

Function of the card:
Ctdl emitter follower-npm
CTDL Emitter Follower - NPN
CTDL-Emitter Follower – NPN

Listed in 1401 SMS card usage

Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.

Part number: 371370

Used in: IBM 1401, IBM 1414 I/O Synchronizer

IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370 IBM SMS card type PQ 371370

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: 2_2 SMS Cards, p53
Coslet data
National Museum of Computing.
This page created by Ken Shirriff on Wed Sep 15 18:15:10 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.