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

Function of the card:
CTDL Power Inverter "P" Type
CTDL Power Inverter NPN
CTDL-Power Inverter ā€œPā€ Type

Listed in 1401 SMS card usage

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

Part number: 371676

Used in: IBM 1401, IBM 1410


IP: Inverter, Power. Performs function of an inverter white also driving a line.
IBM SMS card type NU 371676 IBM SMS card type NU 371676

Image courtesy of Randall Neff

References: 1410_SMS_VOL_2.pdf, p107
IBM Standard Modular System, Component Circuits, p233
2_2 SMS Cards, p50
Coslet data
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.