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

Function of the card:
CTDL Load Code
Ctdl load card
CTDL-Load Card

Listed in 1401 SMS card usage

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

Part number: 371929

PCB number: 493227

Used in: IBM 1401, IBM 1410, IBM 1414 I/O Synchronizer

Symbol:L

L: Limiter or Clamp. Limits or clamps a voltage or current to a predetermined value.
IBM SMS card type AEA 371929 IBM SMS card type AEA 371929 IBM SMS card type AEA 371929 IBM SMS card type AEA 371929

Image courtesy of Randall Neff

Pinout:

A
B
C
D
E
F
G
H
J GND
K -6V
L +6V
M -12V
N
P
Q +6VM
R -12VM
References: 1410_SMS_VOL_2.pdf, p115
Coslet data
National Museum of Computing.
1_2 SMS Cards, p57

This page created by Ken Shirriff on Wed Sep 15 18:15:10 2021.

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.