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

Function of the card:
Partial volt. reg. + sense gate gen.
Partial Volatge Regulator and Sense Gate Gen.
Voltage regulator + sense gate #1

Part number: 372227

Customer Eng reference number: 734399

Used in: IBM 1443 Printer, IBM 2821 Control Unit

IBM SMS card type YKY 372227 IBM SMS card type YKY 372227

References: IBM 2821 CCD, p101
IBM 1443 ALD, p125
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.