Page of 5Y20-0884-3 As Updated Aug. 1, 1979 by 5N25-0497 (March 1979)
This is a major revision of, and obsoletes, SY20-0884-2 and Technical
Newsletters SN25-0413, SN25-0453, and SN25-0466. This edition (SY20-0884-3) together with Technical Newsletter SN25-0491, dated August
1, 1919, applies to Release 6 PLC 4 (Program Level change) of the IBM Virtual Machine Facility/370, and to all subsequent releases unless
otherwise indicated in new editions or Technical Newsletters.
Technical changes and additions to text and illustrations are indicated
by a vertical bar to the left of the change.
Changes are periodically made to the information herein; before using
this pUblication in connection with the operation of IBM systems,
consult the latest Order No. GC20-0001, for
the editions that are applicable and current.
It is possible that this material may contain references to, or
information about, IBM products (machines and programs), programming, or
services that are not announced in your country. Such references or
information must not be construed to mean that IBM intends to announce
such IBM products, programming, or services in your country.
Publications are not stocked at the address given below; requests for
copies of IBM publications should be made to your IBM representative or
to the IBM branch office serving your locality.
A form for readers' comments is provided at the back of this
publication. If the form has been removed, comments may be addressed to IBM Corporation, VM/310 publications, Dept. D58, Bldg. 106-2, P.O. Box 390, Poughkeepsie, New York 12602. IBM may use or distribute any of the
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© Copyright International Business Machines Corporation 1976, 1977, 1979

Page of SY20-0884-3 As Updated Aug. 1, 1979 by SN25-0497 This publication contains descriptions of
major data areas and control blocks used by
the three major compoQents of VM/370. The
three components are: • The control Program (CP) • The Conversational Monitor System (CMS) • The Remote Spooling
Subsystem (RSCS) Communications
There are three sections
appendixes, as follows:
and five • "Section 1. CP Data Areas and Control
Blocks" contains information about CP data areas and control blocks. • "Section 2. CMS Data "Areas and Control
Blocks" contains information on CMS data
areas and control blocks. • "Section 3. RSCS Data Areas and Control
Blocks" contains information on RSCS data areas and control blocks. • "Appendix A. CP and RSCS Equate Symbols"
contains assembler language equate
symbols used by CP and RSCS to reference
data. • "Appendix B. RSCS Control Areas"
contains RSCS control areas that define
constants and variables used during
execution .. • "Appendix C. RSCS Request Elements"
contains RSCS request elements that are
the tables used by RSCS for task-to-task
communication. • "Appendix D. CMS Equate
contains CMS equate symbols. Symbols" • "Appendix E. Data Areas and Control
Block References" contains information
on the modules that reference data areas
and control blocks. OTHER VM/370 DATA AREAS AND CONTROL BLOCKS Some data areas and control blocks that
affect VM/370 service and support programs
are not included in this publication.
Information on these data areas and control
blocks can be found in the RELATED PUBLICATIONS This publication
conjunction with:
should be
Preface
used in Logi£ Qetermi.!@tiQB Gu!de, !olumg 1 Order No. SY20-0886 QYiQg, Order No. GC20-1807 For information on how to use the fourth
component interactive problem control
system --and its facilities, the hardware
and software support personnel or the
installation system programmer should use:
This publication addresses and describes
the major control blocks associated with CP, CMS, and RSCS. Generally, data areas,
or scratch areas that are created and exist
only during the execution of a particular
module are not described in this
publication. In this publication, the data and control blocks are arranged in
alphabetical order by DSECT name.
The CMS and RSCS components operate
under control of CPo Each component
creates, updates, and erases its own
control blocks and data areas. Preface iii