Function of the card:
2-5 Way (-A-O) DLB Load or No Load H. S.
2-5 way -a-0 dlb w or wo/load h.s.
Part number: 372525
Customer Eng reference number: 734375
PCB number: 484961
Used in: IBM 2821 Control Unit
Cap code: None (details)
Symbol: R, -O, -A
R: Load. Provides proper terminating impedance or optimum coupling of one circuit to another at the correct operating voltage level.
-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.
National Museum of Computing.
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.