Function of the card:
SDTDL 4-3 way (-a,-0) wo/load
SDTDL 4-3 way. -a-o wo/load
Saturated Drift Transistor Diode Logic (SDTDL) is a form of Diode-transistor logic using faster drift-field transistors.
Part number: 372236
Customer Eng reference number: 734321
PCB number: 484985
Used in: IBM 1311 Disk, 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 2821 CCD, p34
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.