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

Function of the card:
SDTDL-Non-Inverting Power Driver
SDTDL non inverting power driver
Emitter follower
SDTDL non-inverting power driver

Listed in 1401 SMS card usage
Quad Emitter Follower

Saturated Drift Transistor Diode Logic (SDTDL) is a form of Diode-transistor logic using faster drift-field transistors.

Part number: 370226

Customer Eng reference number: 729911

PCB number: 484043 , hole pattern: 491329

Used in: IBM 1401, IBM 1410, IBM 2821 Control Unit, IBM 1311 Disk, IBM 1443 Printer

Symbol:DP

DP: Driver, Power. A power driver used to drive Into multiple bases.
IBM SMS card type DFR 370226 IBM SMS card type DFR 370226 IBM SMS card type DFR 370226 IBM SMS card type DFR 370226

Pinout:

A O1
B O2R
C I1
D I2
E O2
F O1R
G O4R
H I3
J GND
K +?V
L O3
M -12V
N
P I4
Q O4
R O3R
References: IBM 1311 ILD, p116
Coslet data
2_2 SMS Cards, pp79,80
IBM 1443 ALD, p93
IBM 2821 CCD, p44
1410_SMS_VOL_1.pdf, p43

This page created by Ken Shirriff on Wed Sep 15 18:15:11 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.