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

Function of the card:
Ctdl-3 way and npn one load
Ctdl-3 way "and" npn one load
Three-Way +AND (1 load)
CTDL- 3 Way “And” NPN One Load
CTDL Three Way "AND" NPN, Two on Card

Listed in 1401 SMS card usage

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

Part number: 371269

Used in: IBM 1401, IBM 1410, IBM 1414 I/O Synchronizer, IBM 7070

Cap code: VU (details)


+A: Positive AND. in-phase output is positive only when all inputs are positive. Out-of-phase output is negative for the above condition.
IBM SMS card type CKVU 371269 IBM SMS card type CKVU 371269 IBM SMS card type CKVU 371269 IBM SMS card type CKVU 371269

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: Coslet data
1_2 SMS Cards, pp34,94
IBM Standard Modular System, Component Circuits, p46
National Museum of Computing.
1410_SMS_VOL_2.pdf, p73
1401 Pocket Reference Manual
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, 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.