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

Function of the card:
CTRL-SS Timing Card #4
Ctrl-ss timing card #4
CTRL SS Timing Card #4
Single Shot Timing Card 4

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

Part number: 371624

Used in: IBM 1414 I/O Synchronizer, IBM 1410, 7030


SS: Single Shot. Provides a monostable output which can be pulsed into its quasi-stable state for a predetermined duration. with each input triggering pulse or triggering voltage change. Once triggered, the output pulse duration becomes independent of input time duration or amplitude.
IBM SMS card type MM 371624 IBM SMS card type MM 371624

References: IBM Standard Modular System, Component Circuits, p223
1410_SMS_VOL_2.pdf, p97
National Museum of Computing.
This page created by Ken Shirriff on Wed Sep 15 18:15:11 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.