Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### DPSBK

Prolog

Control Block Contents
DPSBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### DPSBK Prolog

     NAME       : HCPDPSBK
     DESCRIPTION: Dasd Programming Services Block
     DSECT      : DPSBK
     FUNCTION   : This DSECT maps each entry in the device table
                  located in module HCPBST.
     LOCATED BY : HCPBSTBL in module HCPDPS is device table origin
     CREATED BY : Device table is predefined, not allocated at
                  run time
     DELETED BY : Never deleted
     SERIALIZED : The device table is read only, never updated

#### DPSBK Control Block Content

#### DPSBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      DPSBK          Dasd Programming Services Block
    0000    0 Bitstring    1 DPSBLKSZ       Supported blocksize
    0001    1 Bitstring    1 DPSINDEX       3 bit representation These are
                                            the values for each element in
                                            the 3-bit maps that indicate by
                                            cylinder whether it is std,
                                            non-std, or non-cachable.
                                         Also:
                                         adding 7 to the value in this
                                         field ('std cyl size x' only)
                                         results in a shift value to
                                         calculate the number of
                                         records of size 'x' in a
                                         given amount of storage.
                                         E.G. DPSINDEX = DPSI1K = 3
                                         => 3+7=10 => 2**10=1K. Shift
                                         number of bytes right 10 bits
                                         gives number of 1K-byte
                                         records in that storage.
                                         (4 per 4K page).
                 3 bit representation of sizes:
              00000001       DPSI256        1 3 bits for std cyl size 256
              00000002       DPSI512        2 3 bits for std cyl size 512
              00000003       DPSI1K         3 3 bits for std cyl size 1K
              00000004       DPSI2K         4 3 bits for std cyl size 2K
              00000005       DPSI4K         5 3 bits for std cyl size 4K
              00000006       DPSINS         6 3 bits for non-standard cyl
              00000007       DPSINC         7 3 bits for non-cachable cyl
    0002    2 Signed       2 DPSRECPC       Records per cylinder for this
                                            blocksize
    0004    4 Signed       2 DPSTKPC        Tracks per cylinder
    0006    6 Signed       2 DPSRCPTK       Records per track for this
                                            blocksize
    0008    8 Signed       2 DPSPGPT        Pages needed to hold track
    000A   10 Bitstring    1 DPSFLAG        Device dependencies
              1... ....      DPSRMCKD       X'80' DPSRMCKD Supports read
                                            multiple count key data CCWs
              .1.. ....      DPSOVFL        X'40' DPSOVFL Minidisk formatted
                                            with overflow records
              ..1. ....      DPSFBA         X'20' DPSFBA FBA device
              .... ....      DPSNODEP       X'00' DPSNODEP No dependencies
    000B   11 Bitstring    1 DPSPTEIX       Index to PTE set for this sz
    000C   12 Bitstring    4 DPSSECTR       Address of sector values for
                                            records of this blocksize
    0010   16 Bitstring    1 DPSNEXT (0)    Next entry in device table
              00000004       DPSSHIFT       4 Size of the DPSBK as a shift
                                            value (power of 2).
                                            2**4=16=DPSSIZEB

#### DPSBK Storage Layout

    *** DPSBK - Dasd Programming Services Block
    *
    *     +------+------+-------------+-------------+-------------+
    *   0 |:BLKSZ|:INDEX|  DPSRECPC   |  DPSTKPC    |  DPSRCPTK   |
    *     +------+------+------+------+-------------+-------------+
    *   8 |  DPSPGPT    |:FLAG |:PTEIX|         DPSSECTR          |
    *     +-------------+------+------+---------------------------+
    *
    *** DPSBK - Dasd Programming Services Block

#### DPSBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    DPSBLKSZ       0000
    DPSFBA         000A 20
    DPSFLAG        000A
    DPSINC         0001 00000007
    DPSINDEX       0001
    DPSINS         0001 00000006
    DPSI1K         0001 00000003
    DPSI2K         0001 00000004
    DPSI256        0001 00000001
    DPSI4K         0001 00000005
    DPSI512        0001 00000002
    DPSNEXT        0010
    DPSNODEP       000A 00
    DPSOVFL        000A 40
    DPSPGPT        0008
    DPSPTEIX       000B
    DPSRCPTK       0006
    DPSRECPC       0002
    DPSRMCKD       000A 80
    DPSSECTR       000C
    DPSSHIFT       0010 00000004
    DPSTKPC        0004

This information is based on z/VM V6R1.0. Last updated on 18 Feb 2010 at 08:35:49 EDT.
Copyright IBM Corporation, 1990, 2008