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

Function of the card:
SDTRL - inverter, 2 way, unloaded collectors
SDTRL-inverter, 2 way, unloaded collectors
SDTRL-Inverter, 2 Way, Unloaded Collectors
SDTRL-inv 2 way unloaded collectors

Listed in 1401 SMS card usage
Quad 2 Input Open Collector NAND

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

Part number: 370084

PCB number: 492867

Used in: IBM 1620, IBM 1410, IBM 1414 I/O Synchronizer, IBM 1311 Disk, IBM 729V, 1622

Symbol:E, A, O


A I2
B I1
C O3
D I1
E I3
F I3
G O1
H I2
K O4
M -12V
N +12VM
P O2
Q I4
R I4
References: Coslet data
1410_SMS_VOL_1.pdf, p6
IBM 1311 ILD, p111
IBM 1620 Instructional System Diagrams, p479
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, 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.