Function of the card:
SDTDL memory 1.200 usec delay line
SDTDL memory 1.2 usec delay line
SDTDL memory 1.200 usec delay line.
Part number: 370249
Customer Eng reference number: 734352
PCB number: 493389 , hole pattern: 492672
Image courtesy of Henk Stegeman
IBM 2821 CCD, p48
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.