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 “P” Type
CTDL Power Inverter 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: 371676

Used in: IBM 1410, IBM 1401

Cap code: None (details)

Symbol: IP

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

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.