Function of the card:
Emitter Follower PNP
Ctdl - emitter follower pnp
CTDL-Emitter Follower PNP
Listed in 1401 SMS card usage
Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.
Part number: 371259
PCB number: 491005
Used in: 7030, IBM 1410, IBM 1401, IBM 7070
Cap code: WT (details)
Symbol: DE
DE: Driver Emitter Follower. A driver, operating on the emitter follower principle, used for power amplification, impedance matching, and isolation without inversion. Often used as a logical element.
Image courtesy of Randall Neff
Image courtesy of Henk Stegeman
IBM Standard Modular System, Component Circuits, p52
1410_SMS_VOL_2.pdf, p71
Coslet data
SMS Cap Code Templates & Index
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.