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
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
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 |
Coslet data
2_2 SMS Cards, pp79,80
IBM 1443 ALD, p93
IBM 2821 CCD, p44
1410_SMS_VOL_1.pdf, p43
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.