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

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

Listed in 1401 SMS card usage
Quad Inverter

Complemented Transistor Resistor Logic (CTRL) is IBM's term for a form of resistor-transistor logic.

Part number: 371487

PCB number: 492793

Used in: IBM 1620, 1622, IBM 729V, 1626

Symbol:I, A, O

IBM SMS card type MH 371487 IBM SMS card type MH 371487

Image courtesy of Henk Stegeman

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: IBM 1620 Instructional System Diagrams, p485
Coslet data
1626 Plotter Parts
IBM 1620 FE Catalog

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.