LOCDSECT | Back to Index page

| Prolog Control Block Contents LOCDSECT DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

LOCDSECT Control Block Content | Top of page

     LOCDSECT DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      LOCDSECT       ,
    0000    0 Bitstring   16 LOCAREA (0)
    0000    0 Bitstring    1 LOCOP          OPERATION CODE
                            ***************ORIENTTAION
                           /      -------- OPERATION CODE
                         --      /
                           ------
              000000C0       LOCORIDX       B'11000000' ORIENTATION=INDEX
              00000040       LOCORHMA       B'01000000' ORIENTATION=HOME
                                            ADDRESS
              00000000       LOCORCNT       B'00000000' ORIENTATION=COUNT
              00000080       LOCORDAT       B'10000000' ORIENTATION=DATA
              00000001       LOCCMDWD       B'00000001' COMMAND=01 WRITE DATA
              00000003       LOCCMDFW       B'00000011' COMMAND=03 FORMAT
                                            WRITE
              00000006       LOCCMDRD       B'00000110' COMMAND=06 READ DATA
              0000000B       LOCCMDWT       B'00001011' COMMAND=0B WRITE
                                            TRACK
              0000000C       LOCCMDRT       B'00001100' COMMAND=0C READ TRACK
              00000016       LOCCMDRE       B'00010110' COMMAND=16 READ
                 VALID COMMAND CODE COMBINATIONS:
              000000C3       LOCIDXFW       LOCORIDX+LOCCMDFW INDEX & 03
                                            FORMAT WRITE
              000000D6       LOCIDXRE       LOCORIDX+LOCCMDRE INDEX & 16 READ
              00000043       LOCHMAFW       LOCORHMA+LOCCMDFW HOME & 03
                                            FORMAT WRITE
              00000056       LOCHMARE       LOCORHMA+LOCCMDRE HOME & 16 READ
              0000004C       LOCHMART       LOCORHMA+LOCCMDRT HOME & 0C READ
                                            TRACK
              00000046       LOCHMARD       LOCORHMA+LOCCMDRD HOME & 06 READ
                                            DATA
              00000003       LOCCNTFW       LOCORCNT+LOCCMDFW COUNT & 03
                                            FORMAT WRITE
              00000016       LOCCNTRE       LOCORCNT+LOCCMDRE COUNT & 16 READ
              0000000C       LOCCNTRT       LOCORCNT+LOCCMDRT COUNT & 0C READ
                                            TRACK
              00000006       LOCCNTRD       LOCORCNT+LOCCMDRD COUNT & 06 READ
                                            DATA
              0000000B       LOCCNTWT       LOCORCNT+LOCCMDWT COUNT & 0B
                                            WRITE TRACK
              00000001       LOCCNTWD       LOCORCNT+LOCCMDWD COUNT & 01
                                            WRITE DATA
              00000096       LOCDATRE       LOCORDAT+LOCCMDRE DATA & 16 READ
              00000086       LOCDATRD       LOCORDAT+LOCCMDRD DATA & 06 READ
                                            DATA
              00000081       LOCDATWD       LOCORDAT+LOCCMDWD DATA & 01 WRITE
                                            DATA
    0001    1 Bitstring    1 LOCAUX         AUXILLIARY BYTE
              1... ....      LOCAXTLF       B'10000000' LOCAXTLF TLF IS
                                            NON-ZERO
              .... ...1      LOCAXLR0       B'00000001' LOCAXLR0 LAST CCW IS
                                            "READ COUNT"
    0002    2 Bitstring    1 *              RESERVED
    0003    3 Bitstring    1 LOCCOUNT       NUMBER OF RECORDS, MUST BE > 0
    0004    4 Bitstring    4 LOCSEEK (0)    SEEK ADDRESS
    0004    4 Signed       2 LOCSKCC        SEEK CYLINDER
    0006    6 Signed       2 LOCSKHH        SEEK HEAD
    0008    8 Bitstring    5 LOCSRCH (0)    SEARCH ADDRESS
    0008    8 Signed       2 LOCSRCC        SEARCH CYLINDER
    000A   10 Signed       2 LOCSRHH        SERACH HEAD
    000C   12 Bitstring    1 LOCSRR         SEARCH RECORD
    000D   13 Bitstring    1 LOCSECTR       SECTOR NUMBER
    000E   14 Signed       2 LOCTLF         TRANSFER LENGTH FACTOR (AVG
                                            BLKSIZE)
                 DASD COUNT FILED DEFINITION

LOCDSECT Storage Layout | Top of page

    *** LOCDSECT - Control Block in LOCDSECT
    *
    *     +------+------+------+------+-------------+-------------+
    *   0 |LOCOP |LOCAUX|//////|:COUNT|  LOCSKCC    |  LOCSKHH    |
    *     +------+------+------+------+------+------+-------------+
    *   8 |  LOCSRCC    |  LOCSRHH    |LOCSRR|:SECTR|   LOCTLF    |
    *     +-------------+-------------+------+------+-------------+
    *  10
    *
    *** LOCDSECT - Control Block in LOCDSECT

LOCDSECT Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    LOCAREA        0000
    LOCAUX         0001
    LOCAXLR0       0001 01
    LOCAXTLF       0001 80
    LOCCMDFW       0000 00000003
    LOCCMDRD       0000 00000006
    LOCCMDRE       0000 00000016
    LOCCMDRT       0000 0000000C
    LOCCMDWD       0000 00000001
    LOCCMDWT       0000 0000000B
    LOCCNTFW       0000 00000003
    LOCCNTRD       0000 00000006
    LOCCNTRE       0000 00000016
    LOCCNTRT       0000 0000000C
    LOCCNTWD       0000 00000001
    LOCCNTWT       0000 0000000B
    LOCCOUNT       0003
    LOCDATRD       0000 00000086
    LOCDATRE       0000 00000096
    LOCDATWD       0000 00000081
    LOCHMAFW       0000 00000043
    LOCHMARD       0000 00000046
    LOCHMARE       0000 00000056
    LOCHMART       0000 0000004C
    LOCIDXFW       0000 000000C3
    LOCIDXRE       0000 000000D6
    LOCOP          0000
    LOCORCNT       0000 00000000
    LOCORDAT       0000 00000080
    LOCORHMA       0000 00000040
    LOCORIDX       0000 000000C0
    LOCSECTR       000D
    LOCSEEK        0004
    LOCSKCC        0004
    LOCSKHH        0006
    LOCSRCC        0008
    LOCSRCH        0008
    LOCSRHH        000A
    LOCSRR         000C
    LOCTLF         000E

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:32:28 EDT.
Copyright IBM Corporation, 1990, 2020