Function of the card:
CTDL Low Current Indicator Driver
Alloy-indicator driver 15 ma
Germanium alloy transistors were an early type of transistor, faster than the earlier grown-junction transistors.
Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.
Part number: 371528
Used in: IBM 1410, 7030, IBM 7070
Cap code: None (details)
Symbol: DI
DI: Driver, Indicator. Driver operating into an indicating device.
IBM Standard Modular System, Component Circuits, p132
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.