Function of the card:
Trigger
CTDL-Trigger
Ctdl trigger
Listed in 1401 SMS card usage
Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.
Trigger is IBM's term for a flip flop or latch.
Part number: 371534
PCB number: 493211 , hole pattern: 491450
Used in: 7030, IBM 1410, IBM 1401, IBM 7070
Cap code: None (details)
Symbol: T
T: Trigger. A conditioned bi-stable device whose steady-state outputs change from one stable state to the other with two separate triggering levels, pulses, or voltage changes. The set input turns the trigger on if the reset input Is not on, and vice versa.
Image courtesy of Randall Neff
Image courtesy of Henk Stegeman
Image courtesy of Eric Schlaepfer
2_2 SMS Cards, pp4,5
1410_SMS_VOL_2.pdf, p89
Coslet data
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.