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

Function of the card:
SDTRL-Trigger, Binary
SDTRL- trigger, binary

AC Coupled RS Flip-Flop

Trigger is IBM's term for a flip flop or latch.

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

Part number: 371867

PCB number: 492907

Used in: IBM 1620, 1622

Symbol:TB

TB: Trigger (Binary). A trigger whose steady state outputs change upon the transition of the input, i.e., usually going plus to minus, or sometimes going minus to plus.
IBM SMS card type VJ 371867 IBM SMS card type VJ 371867

Image courtesy of Eric Schlaepfer

Pinout:

A RG1
B Q
C *R
D RP1
E RG2
F RP2
G RR1
H *S
J GND
K SG2
L SP2
M -12V
N +12VM
P *Q
Q SP1
R SG1
References: IBM 1620 Instructional System Diagrams, p495
Coslet data
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.