Function of the card:
CTDL Logic Inverter (NPN)
Cidl logic inverter npn no loads
Ctdl logic inverter npn all loads
CTDL-Logic Inverter NPN All Loads
Listed in 1401 SMS card usage
Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.
Part number: 371079
Used in: IBM 1410, IBM 1401, IBM 7070, IBM 1414 I/O Synchronizer, 7030
Cap code: VB (details, details)
Symbol: I
I: Inverter. Changes a positive input to a negative output, or vice versa.
Image courtesy of Randall Neff
Image courtesy of Henk Stegeman
IBM Standard Modular System, Component Circuits, p162
2_2 SMS Cards, p36
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.