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

Function of the card:
Alloy-thermoswitch n/c 122 deg f
7106/7107 Core Storage
Alloy-Thermoswitch N/C 122F
Alloy-thermoswitch n/c 122f
122F N/C thermal card
Alloy-thermoswitch n/c 122*f

Overtemperature Switch

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

Part number: 371699

PCB number: 492955

Used in: IBM 1311 Disk, IBM 7090, IBM 1620, IBM 1414 I/O Synchronizer, 1622, 7040

Cap code: None (details)

Symbol: THER

IBM SMS card type RE 371699 IBM SMS card type RE 371699

Image courtesy of Eric Schlaepfer


C J1
D J1
E spare
F I1
H O1
J spare
P spare
Q spare
R spare
References: IBM 1620 FE Catalog
IBM 1311 ILD, p134
IBM 1620 Instructional System Diagrams, p490
Standard Module System Reference
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.