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

Function of the card:
Alloy-Switch,Decoder

Dual 4 Input Open Collector OR Buffer 270mA

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

Part number: 372122

PCB number: 484803

Used in: IBM 1620

Cap code: None (details)

Symbol: SWD

Pinout:

A I1
B I1
C I1
D I1
E O1
F I2
G I2
H I2
J GND
K O2
L I2
M -12V
N +30V
P -36V
Q
R
References: 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.