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

Function of the card:
CTRL Emitter Follower NPN
Ctrl-emitter follower npn

Listed in 1401 SMS card usage

Complemented Transistor Resistor Logic (CTRL) is IBM's term for a form of resistor-transistor logic.

Part number: 371033

Used in: IBM 1410, IBM 729II, IBM 7090, 7030


DE: Driver Emitter Follower. A driver, operating on the emitter follower principle, used for power amplification, impedance matching, and isolation without inversion. Often used as a logical element.
IBM SMS card type CFYA 371033 IBM SMS card type CFYA 371033

References: IBM Standard Modular System, Component Circuits, pp214,215
1410_SMS_VOL_2.pdf, p57
This page created by Ken Shirriff on Wed Sep 15 18:15:09 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.