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

Function of the card:
Ctrl-oscillator, 10 kc free running (crystal)
CTRL-Oscillator, 10 KC Free Running (Crystal)

Listed in 1401 SMS card usage

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

Part number: 371245

Used in: IBM 1410, IBM 1401

Cap code: None (details)

IBM SMS card type JB 371245 IBM SMS card type JB 371245 IBM SMS card type JB 371245

Image courtesy of Philipp Müller
Image courtesy of Göran Axelsson

References: 2_2 SMS Cards, pp113,114
1410_SMS_VOL_2.pdf, p68
Coslet data
National Museum of Computing.

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.