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

Function of the card:
CTRL-Emitter Followers,Low Current
Ctrl-emitter followers, low current

Quad Emitter Follower (Photodiode Amplifier)

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

Part number: 371778

Used in: IBM 1620

Cap code: None (details)

Symbol: AM

AM: Amplifier. Provides increased strength to a detected signal or pulse.
IBM SMS card type PH 371778 IBM SMS card type PH 371778

Image courtesy of Christoph Methfessel

Pinout:

A O1
B I1
C O2
D I2
E O4
F O3
G I4
H I3
J
K
L +12V
M -12V
N
P
Q +12V
R
References: IBM 1620 Instructional System Diagrams, p488
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.