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

Function of the card:
Mup /4
MUP Number 4
SDTDL mup number 4
SDTDL-MUP Number 4

Listed in 1401 SMS card usage

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

A Multiple-Use Package (MUP) card has circuits jumpered together directly on the card to form more complex circuits.

Part number: 370352

Customer Eng reference number: 729928

PCB number: 484131

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

IBM SMS card type DHJ 370352 IBM SMS card type DHJ 370352

References: Coslet data
IBM 2821 CCD, p60
2_2 SMS Cards, pp105,106,107
IBM 1443 ALD, p104
1410_SMS_VOL_1.pdf, p91
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, 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.