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

Function of the card:
CTDL Extender Card
Extender and Limiter Card
CTDL-Extender Card
Ctdl extender card

Listed in 1401 SMS card usage

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

Part number: 371075

Used in: IBM 1401, IBM 1410, IBM 1414 I/O Synchronizer, IBM 7070

Symbol:E

E: Extender. Provides additional inputs to logical blocks and triggers. Adds to drivers the ability to drive more loads.
IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075 IBM SMS card type CLVR 371075

Image courtesy of Randall Neff

References: 1410_SMS_VOL_2.pdf, p62
1_2 SMS Cards, pp35,99
Coslet data
National Museum of Computing.
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.