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

Function of the card:
P to N Converter, Type B (no loads)

Part number: 371311

Used in: IBM 7090

Cap code: None (details)

Symbol: C

C: Converter. Used to translate from one voltage level to another, or to change the amplitude of the voltage swing about the same reference level.
IBM SMS card type DD 371311 IBM SMS card type DD 371311

Image courtesy of Computer History Museum

References: IBM Standard Modular System, Component Circuits, p73

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.