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

Function of the card:
Power supply
Overvoltage Protection 12 Volt

Crowbar

Part number: 370576

PCB number: 484337

Used in: IBM 1620, 7040

Symbol:OV

IBM SMS card type YGB 370576 IBM SMS card type YGB 370576 IBM SMS card type YGB 370576

Image courtesy of The DHTS Store

Pinout:

A NEG
B NEG
C NEG
D NEG
E NEG
F NEG
G NEG
H POS
J POS
K POS
L POS
M POS
N POS
P POS
Q
R BIAS
References: Coslet data
1_2 SMS Cards, pp8,10,11

This page created by Ken Shirriff on Wed Sep 15 18:15:09 2021.

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.