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

Function of the card:
Two-Way+AND (all loads)
CTDL-Two Way “And” 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: 371252

Used in: IBM 1401, IBM 7070

Cap code: WW (details)

Symbol:+A

+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 CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252 IBM SMS card type CHWW 371252

Image courtesy of Randall Neff
Image courtesy of Henk Stegeman

References: IBM Standard Modular System, Component Circuits, p43
1_2 SMS Cards, pp30,31,32,89
Coslet data
1401 Pocket Reference Manual
This page created by Ken Shirriff.

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 self.data and Jim Hunt's self.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.