This page describes the IBM SMS card "GR", and is part of the SMS card database.

Function of the card:
CTDL Low Current Indicator Driver
Alloy-indicator driver 15 ma

Complemented Transistor Diode Logic (CTDL) is IBM's term for a form of diode-transistor logic.

Germanium alloy transistors were an early type of transistor, faster than the earlier grown-junction transistors.

Part number:371528

Used in:IBM 7070,IBM 1410

Symbol:DI

DI: Driver, Indicator. Driver operating into an indicating device.

Family: current mode

References:
IBM Standard Modular System, Component Circuits, p132.
1410_SMS_VOL_1.pdf/1410_SMS_VOL_2.pdf, p2087.
This page created by Ken Shirriff, 2015.

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. Images courtesy of Randall Neff. Much of this information was obtained through OCR, so don't expect complete accuracy. These pages are not associated with IBM in any way.

Creation time: Tue Mar 03 23:40:33 2015.