Page of sY20-0884-3 As Updated Aug. 1, 1979 by sN25-0497
Control blocks and data areas are blocks
of related information applicable to one or
more system functions. They are usually
definedby the DsECT instruction. The
blocks can reflect current status, history
information, or combinations of both,
applicable toV8/370 functions. Control
blocks and data areas provide the linkage
and information for the user, the hardware,
and the programs to work 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 andCMs control areas are 8 bytes wide, showing two
fullwords per line. RsCs control blocks
are4 bytes wide.
the formatting for PsA, where the control
areas are given in 16-byte width.When the name of a field is too large to
fit into the formatted line, a pointer to
the definition of the field is used instead
of thename of the field. This pointer
usually takes the form A*1,A*2. etc. When there is a particularly large field (one
that uses more 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 forIBM'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 IBM 2305 Fixed Head
storage, Models 1 and 2.• "270x" refers to
2703 TransmissionIBM 2701, 2702, and
ControlUnits or the Integrated Communications Adapter (lCA) on the system/370 Model 135. • "2741" refers to the IBM 2741 and the
3767, unless otherwise specified.• "3270" refers to a series of display
devices, namely, theIBM 3275, 3276,
3277, and 3278 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 theIBM 3138, 3148, and
3158 Display Consoles when used in
display mode, unless otherwise noted.
Any information pertaining to theIBM 3284 or 3286 Printer also pertains to
theIBM 3287, 3288, and 3289 printers,
unless otherwise noted.• "3330" refers to the IBM 3330 Disk
storage,Models 1, 2, or 11; the IBM 3333 Disk Storage and Control, Models 1
or 11; and the 3350 Direct Access
Storage operating in 3330/3333Model 1
or 3330/3333Model 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 IBM 3350 Direct
Access StorageModels A2 and B2 in
native mode.
"370x" refers toIBM 3704 and 3705
Communications Controllers.
The term "3705" refers to the 3705 I and
the 3705 II unless otherwise noted.
ivIBM VM/370 Data Areas and Control Blocks Logic
Control blocks and data areas are blocks
of related information applicable to one or
more system functions. They are usually
defined
blocks can reflect current status, history
information, or combinations of both,
applicable to
blocks and data areas provide the linkage
and information for the user, the hardware,
and the programs to work 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
fullwords per line. RsCs control blocks
are
the formatting for PsA, where the control
areas are given in 16-byte width.
fit into the formatted line, a pointer to
the definition of the field is used instead
of the
usually takes the form A*1,
that uses more 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
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:
storage, Models 1 and 2.
2703 Transmission
Control
3767, unless otherwise specified.
devices, namely, the
3277, and 3278 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
3158 Display Consoles when used in
display mode, unless otherwise noted.
Any information pertaining to the
the
unless otherwise noted.
storage,
or 11; and the 3350 Direct Access
Storage operating in 3330/3333
or 3330/3333
mode.
storage,
Access Storage
native mode.
"370x" refers to
Communications Controllers.
The term "3705" refers to the 3705 I and
the 3705 II unless otherwise noted.
iv
