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

Function of the card:
Emitter Follower NPN
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: 371260

Used in: IBM 1401, IBM 1410, 7030, IBM 7070

Symbol:DE

DE: Driver Emitter Follower. A driver, operating on the emitter follower principle, used for power amplification, impedance matching, and isolation without inversion. Often used as a logical element.
IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260 IBM SMS card type CNWT 371260

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: 1_2 SMS Cards, p103
1410_SMS_VOL_2.pdf, p72
Coslet data
IBM Standard Modular System, Component Circuits, p50
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.