This publication contains descriptions of major data areas and control blocks used by the three major components of V"/370. The
three cOllponents are: I The Control Prograll (CP) I The Conversational Monitor System (CMS) I The Remote Spooling I Subsystem (RSCS) Comllunications 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 eleaents 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 ViItua! Preface Facil!llL37.Q: Service Routi!!es 19qic, Order No. SY20-0882. RELATEr PUBLICATIONS This putlication
conjunction with:
should be used 1 Control Pr.Q.9!U (Q), Order No. 5Y20-0886 in l Conversatienal MCni!.Q£ Order No. Sy20-0887 Guide, Order No. GC20-i807 -
For information on how to use the fourth
component interactive problem centrol system -- and its facilities, the hardware
and software support perscnnel or the
installation system programmer should use: IEM Virtual Machine Facility/370: system Guide, Order No. GC20-1823,. 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 ef a particular module are not described in this
publication. In this publication, the data
areas and control blocks are arranged in
alphabetical order by DSECT name.
The CMS and RSCS cOllponents operate
under control of CP. Each component
creates, updates, and erases its own
control blocks and data areas.
Preface iii
Control blocks and data areas are blocks
of related information applicable to one or aore system functions. They are usually
defined by the DSECT instruction. The
blocks can reflect current status, history
information, or combinations of both,
applicable to VM/310 functions. Control
blocks and data areas provide the linkage
and information for the user, the hardware,
and the programs to vork as one entity for
the successful execution of a job, task. or
process.
For every data area or control block, a statement is given that defines the use of
the data area or control block. This
statement is followed by a formatted block
showing the fields defined in the data area
or control block and the displacement into
the DSECT of that field.
The formatted blocks for CP and CMS control areas are 8 bytes wide, showing two fullwords per line. RSCS control blocks
are 4 bytes vide. !2te: One exception to this width rule is
the formatting for PSA, where the control
areas are given in 16-byte width. When the name of a field is too large to
f it in t 0 the forIa_t.t_e_dli.ne, ap_oin.ter to
the definition of the field is used instead
of the name of the field. This pointer
usually takes the form A*1, A*2, etc. When there is a particularly large field (one
that uses mere than three or four lines of
the formatted block), ellipses are used in
the block to show that the displacement of
this field is larger than can be shown in
the block.
The use of slashes in a field indicates
that the field is reserved for IBM's use.
The formatted block is
listing-related information hexadecimal displacement of
the DSECT, the name of the
definition in the listing,
description of the contents
the field,.
followed by
such as the
the field into
field and its
and a brief
and meaning of
The following terms in this publication,
refer to the indicated support devices: "2305" refers to IB! 2305 Fixed Bead
Storage, Models 1 and 2. "210x" refers to IB! 2101, 2102, and 2103 Transmission Control Units or the
Integrated Communications Adapter (ICA)
on the System/310 Model 135. "2141" refers to the IBM 2141 and the
3161, unless otherwise specified. "3210" refers to a series of display
devices, namely, the IBM 3275, 3216,
3211, and 3218 Display Stations. A specific device type is used only when a
distinction is required between device
types. Information about display terminal usage
also applies to the IBM 3138, 3148, and
3158 Display Consoles when used in
display mode, unless otherwise noted.
Any information pertaining to the IEM 3284 or 3286 Printer also pertains to
the IBM 3281, 3288, and 3289 printers,
unless otherwise noted. "3330" refers to the IBM 3330 Disk
Stor age, .Mo.dels 1, 2, or 11; the IE! 3333 Disk Storage and Control, Models 1
or 11; and the 3350 Direct Access
Storage operating in 3330/3333 Model 1
or 3330/3333 Model 11 compatibility mode. "3340" refers to the IBM 3340 Disk
Storage, Models A2, B1, and B2, and the
3344 Direct Access Storage Model B2. "3350" refers to the
Access Storage Models native mode. IBI! 3350 A2 and
Direct
E2 in "310x" refers to IEM 3704 and 3105 Communications Controllers.
The term "3105" refers to the 3105 I and
the 3705 II unless otherwise noted.
iv IBM VM/310 Data Areas and Control Blocks Logic
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