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

Function of the card:
Alloy hammer driver latch
Alloy-Hammer Driver Latch
Alloy Hammer Driver Latch

Listed in 1401 SMS card usage
Low-speed replacement for AEN, different R16 and fuse.

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

Part number: 371940

PCB number: 493237

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

Cap code: None (details)

Symbol: D

D: Driver. Isolates a signal from its generating source and uses it to drive one or more other circuits without affecting or overloading the generating circuits. Can be used to supply the required power directly or only to activate the circuit through which power is actually supplied.
IBM SMS card type AEC 371940 IBM SMS card type AEC 371940 IBM SMS card type AEC 371940 IBM SMS card type AEC 371940 IBM SMS card type AEC 371940

Image courtesy of Henk Stegeman

References: 1_2 SMS Cards, pp58,59,60
1410_SMS_VOL_2.pdf, p116
National Museum of Computing.
Coslet data

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.