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

Function of the card:
CTDL-Load Card
CTDL Load Code
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 1410, IBM 1414 I/O Synchronizer, IBM 1401

Cap code: None (details)

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 IBM SMS card type AEA 371929 IBM SMS card type AEA 371929

Image courtesy of Christoph Methfessel
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: 1_2 SMS Cards, p57
National Museum of Computing.
1410_SMS_VOL_2.pdf, p115
Coslet data

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.