Function of the card:
CTDL-High Speed Three Way “And” PNP One Load
Three-Way -AND (1 load)
Listed in 1401 SMS card usage
Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.
Part number: 371585
Cap code: VU (details, details)
Symbol: -A
-A: Negative AND. In-phase output is negative only when all inputs are negative. Out-of-phase output is positive for the above condition.
Image courtesy of Christoph Methfessel
Image courtesy of Randall Neff
1_2 SMS Cards, p40
IBM Standard Modular System, Component Circuits, p159
Coslet data
SMS Cap Code Templates & Index
1401 Pocket Reference Manual
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.