IBM 360 Manual page 2

Preface
The IBM Basic Counter Unit is referenced by Field
Engineering Publications as the IBM 2989 Model 11 Basic
Counter Unit. The type number, 2989 Model 11 is used by
the Field Engineering Division for installation and mainte­
nance information recording.
IBM Basic Counter Unit Related Publications:
IBM Basic Counter Unit Probe Assignment Planning
Form, ZX22-6946
IBM Basic Counter Unit Patch Panel Planning Form,
ZX22-6952
IBM 2989 Model 11 Basic Counter Unit, FETOM,
ZY27-2236
IBM Systems Journal, Volume Eight, Number Four,
1969, G321-0019
IBM System /360 I/O Interface, Channel to Control Unit,
OEMI, GA22-6843
Introduction to IBM System /360 Direct Access Storage
Devices and Organization Methods, GC20-1649
IBM System /360 Principles o f Operation, GA22-6821
First Edition (February, 1970)
This edition contains information formerly in, and obsoletes, Form Y22-6934-0.
Changes are periodically made to the specifications herein; any such changes will
be reported in subsequent revisions.
Requests for copies of IBM publications should be made to your IBM
representative or to the IBM branch office servicing your locality.
This manual has been prepared by the IBM Systems Development Division,
Product Publications, Dept. B98, PO Box 390, Poughkeepsie, N.Y. 12602. A form
for readers' comments is provided at the back of this publication. If the form has
been removed, comments may be sent to the above address.
©Copyright International Business Machines Corporation 1970
IBM Internal Use Only