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

Function of the card:
CTDL Delay Circuit

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

Part number: 371570

Used in: IBM 7070


DLY: Delay. Delays a pulse for a certain specified constant time.

References: IBM Standard Modular System, Component Circuits, p171
This page created by Ken Shirriff on Wed Sep 15 18:15:11 2021.

The information on these pages comes from a variety of sources, especially old IBM documents on, 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.