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

Function of the card:
Two-Way -AND (2 loads)
CTDL-High Speed - Two Way “And” PNP Two 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: 371581

Used in: IBM 1401, IBM 7070

Cap code: VW (details, 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 JGVW 371581 IBM SMS card type JGVW 371581

Image courtesy of Randall Neff

References: 1_2 SMS Cards, p38
2_2 SMS Cards, p26
IBM Standard Modular System, Component Circuits, p158
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, 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.