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

Function of the card:
Power Driver Input Clamp N Line

Part number: 371146

Used in: 7030, IBM 7090


L: Limiter or Clamp. Limits or clamps a voltage or current to a predetermined value.

References: Drawing courtesy of Living Computers: Museum + Lab
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.