Function of the card:
SDTDL memory 1.2 usec delay line
SDTDL memory 1.200 usec delay line
SDTDL memory 1.200 usec delay line.
Saturated Drift Transistor Diode Logic (SDTDL) is a form of Diode-transistor logic using faster drift-field transistors.
Part number: 370249
Customer Eng reference number: 734352
PCB number: 493389 , hole pattern: 492672
Used in: IBM 1410, IBM 1311 Disk, IBM 2821 Control Unit
Cap code: None (details)
Symbol: DLY
DLY: Delay. Delays a pulse for a certain specified constant time.
Image courtesy of Henk Stegeman
1410_SMS_VOL_1.pdf, p62
IBM 1311 ILD, p120
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.