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

Function of the card:
Alloy-Switch, Decoder Number 2

Listed in 1401 SMS card usage

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

Part number: 370833

PCB number: 493371

Used in: IBM 1401

Cap code: None (details)

Symbol: SWD

IBM SMS card type AQU 370833 IBM SMS card type AQU 370833 IBM SMS card type AQU 370833

Image courtesy of intabits
Image courtesy of Göran Axelsson

References: Coslet data
1_2 SMS Cards, pp66,67

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.