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

Function of the card:
SDTRL-Oscillator, One MC
SDTRL-oscillator, one mc

1MHz Crystal Oscillator

Saturated Drift Transistor Resistor Logic (SDTRL) is a form of resistor-transistor logic using faster drift-field transistors.

Part number: 371868

Used in: 1622, IBM 1620

Cap code: None (details)

Symbol: OSC

OSC: Oscillator. A free-running non-stable muitivibrator used to provide pulses of a given frequency and amplitude.

Pinout:

A
B
C O1R
D O1
E
F
G
H
J GND
K
L
M -12V
N +12VM
P
Q
R
References: IBM 1620 Instructional System Diagrams, p494
IBM 1620 FE Catalog
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.