Function of the card:
U to T Converter (I load)
CTDL-High Speed One Way NPN One 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: 371589
Cap code: VA (details, details)
Symbol: C
C: Converter. Used to translate from one voltage level to another, or to change the amplitude of the voltage swing about the same reference level.
2_2 SMS Cards, p32
IBM Standard Modular System, Component Circuits, p160
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.