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

Function of the card:
CTDL-High Speed Three Way “And” PNP One Load
Three-Way -AND (1 load)

Listed in 1401 SMS card usage

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

Part number: 371585

Used in: IBM 1401, IBM 7070

Cap code: VU (details)

Symbol:-A

-A: Negative AND. In-phase output is negative only when all inputs are negative. Out-of-phase output is positive for the above condition.
IBM SMS card type JHVU 371585 IBM SMS card type JHVU 371585

Image courtesy of Randall Neff

References: 2_2 SMS Cards, p29
1_2 SMS Cards, p40
Coslet data
IBM Standard Modular System, Component Circuits, p159
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 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.