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

Function of the card:
Drift Logic Driven DL
Drift logic driven dl

Penta 1..3 Input NAND Line Driver

Part number: 370384

PCB number: 493121

Used in: IBM 1620



A O2
B I5
C I3
D I3
E I2
F I1
G I1
H I1
K I4
L O5
M -12V
N +12VM
P O1
Q O3
R O4
References: Coslet data
IBM 1620 Instructional System Diagrams, p480

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.