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

Function of the card:
1-3, 1-2 way -a-o wo/load h.s.

Part number: 372531

Customer Eng reference number: 734381

PCB number: 484959

Used in: IBM 2821 Control Unit

Cap code: None (details)

Symbol: -O, -A

-O: Negative OR. In-phase output is negative if one or more Input signals are negative. Outof-phase output is positive for the above condition.

-A: Negative AND. In-phase output is negative only when all inputs are negative. Out-of-phase output is positive for the above condition.
IBM SMS card type CEY 372531 IBM SMS card type CEY 372531 IBM SMS card type CEY 372531 IBM SMS card type CEY 372531

References: IBM 2821 CCD, p38

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.