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

Function of the card:
Blocking circuit

Part number: 372691

Used in: IBM 1311 Disk

Cap code: None (details)

IBM SMS card type YNR 372691 IBM SMS card type YNR 372691

Image courtesy of Roberto Gonzalez Rocha

References: IBM 1311 ILD, p151

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.