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

Function of the card:
SDTRL -inverter, power- pnp
SDTRL-Inverter, Power-PNP

Quad Inverter

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

Part number: 371871

PCB number: 492913

Used in: IBM 1620, 1622

Symbol:I

I: Inverter. Changes a positive input to a negative output, or vice versa.

Pinout:

A O4
B I3
C O3R
D O2
E O3C
F I4R
G I1C
H I4C
J GND
K I1R
L O1C
M -12V
N +12VM
P I2R
Q I2C
R O1R
References: Coslet data
IBM 1620 Instructional System Diagrams, p496
IBM 1620 FE Catalog

This page created by Ken Shirriff on Wed Sep 15 18:15:10 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.