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

Function of the card:
Ctdl-3-way and npn no loads
CTDL- 3-Way “And” NPN No Loads

Listed in 1401 SMS card usage

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

Part number: 371270

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

Cap code: WF (details, details)

IBM SMS card type CKWF 371270 IBM SMS card type CKWF 371270 IBM SMS card type CKWF 371270 IBM SMS card type CKWF 371270

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: 1_2 SMS Cards, pp34,95
Coslet data
SMS Cap Code Templates & Index
1401 Pocket Reference Manual

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.