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

Function of the card:
Simplex interface driver
SDTRL - standard cable driver
SDTRL-standard cable driver
SDTRL-Standard Cable Driver
SDTRL_Simplex Interface Driver

Quad Line Driver

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

Part number: 371987

PCB number: 493259

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

Symbol:DL, D


A O1
B I3
C I2
D I1
E O2
F I4
G O3
H O4
M -12V
N +12VM
References: 1410_SMS_VOL_2.pdf, p122
Coslet data
IBM 1620 Instructional System Diagrams, p481
IBM 1311 ILD, p111
National Museum of Computing.
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, 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.