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

DOSSECT

Prolog  

Control Block Contents  
   DOSSECT DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


DOSSECT Prolog

 Name       : DOSCB
 Description: DOS Simulation Control Block
 DSECT      : DOSSECT
 Function   : DOSSECT simulates the CMS file control block
              (FCB) in the CMS/DOS environment. DOSSECT is
              called by the DOSCB macro. The DOS simulation
              control blocks are chained together. The
              DOSFIRST field in NUCON points to the first
              DOSCB in the chain, or if no chain exists,
              contains zero.

 

DOSSECT Control Block Content


DOSSECT DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      DOSSECT        DOS Simulation Control Block
0000    0 Bitstring    1 DOSINIT (0)    DOSCB FLAG BYTE
          .1.. ....      DOSOS          X'40' DOSOS CREATED BY 'OS' USER
          ..1. ....      DOSDOS         X'20' DOSDOS DEFINED FOR NON-CMS
                                        DISK
          ...1 ....      DOSCMS         X'10' DOSCMS DEFINED FOR CMS DISK
          .... 1...      DOSDDCAT       X'08' DOSDDCAT USER CATALOG
                                        DATASET
          .... .1..      DOSPERM        X'04' DOSPERM PERMANENT CONTROL
                                        BLOCK
          .... ..1.      DOSJCAT        X'02' DOSJCAT SEARCH VSAM JOB
                                        CATALOG
          .... ...1      DOSUCAT        X'01' DOSUCAT SEARCH VSAM USER
                                        CATALOG
0000    0 Address      4 DOSNEXT        AL3(NEXT DOSCB)
0004    4 Character    4 DOSCBID        'DLBL' TO DISTINGUISH FROM CMSCB
0008    8 Character    8 DOSDD          DATA DEFINITION NAME
0010   16 Character    8 DOSOP          CMS OPERATION
0018   24 Bitstring    1 DOSTAPID (0)   TAPE IDENTIFICATION
0018   24 Character    8 DOSDSNAM       DATASET NAME
0020   32 Character    8 DOSDSTYP       DATASET TYPE
0028   40 Character    2 DOSDSMD        DATASET MODE
002A   42 Signed       2 *              RESERVED
002C   44 Signed       4 DOSBUFF        A(INPUT/OUTPUT BUFFER)
0030   48 Signed       4 DOSBYTE        SIZE OF BUFFER (DATA COUNT)
0034   52 Character    1 DOSFORM        FILE FORMAT: FIXED/VARIABLE
0035   53 Bitstring    1 DOSEPL         EXTENDED PLIST
0036   54 Signed       2 *              RESERVED
0038   56 Signed       4 DOSREAD        N'BYTES ACTUALLY READ
003C   60 Signed       4 DOSITEM        ITEM (RECORD) NUMBER
0040   64 Signed       4 DOSCOUT        RECORDS PER CMS PHYSICAL BLOCK
0044   68 Bitstring    1 DOSDEV         DEVICE TYPE CODE
          .... ....      DOSDUM         0 DOSDUM DUMMY DEVICE
          ...1 .1..      DOSDSK         20 DOSDSK DISK
0045   69 Bitstring    1 DOSTAPMD       RESERVED - This field is no
                                        longer used and considered
                                        undefined
0046   70 Signed       2 DOSBLKSZ       BLOCK SIZE
0048   72 Dbl-Word     8 DOSWORK        WORK AREA
0050   80 Signed       2 DOSYSXXX (0)   LOGICAL UNIT FOR CMS/DOS
0050   80 Bitstring    1 DOSSYS         SYS/PROG UNIT: X'00' =SYS,
                                        X'01'=PROG
0051   81 Bitstring    1 DOSXXX         NUMBER FROM 000-255 ASSOC WITH
                                        UNIT
0052   82 Bitstring    1 DOSEXT         NUMBER DOS EXTENTS LEFT TO
                                        PROCESS
0053   83 Bitstring    1 DOSEXTCT       CURRENT DOS EXTENT
0054   84 Signed       4 DOSOSFST       POINTER TO OS FST
0058   88 Signed       4 DOSOSDSN       POINTER TO OS DSNAME BLOCK
005C   92 Signed       4 DOSVOLTB       A(VOLUME ID TABLE)-VSAM MULTIVOL
                                        DATASET
0060   96 Signed       4 DOSEXTTB       A(EXTENT TABLE) FOR VSAM
                                        DATASPACE
0064  100 Signed       2 DOSSENSE       I/O SENSE DATA
0066  102 Bitstring    1 DOSVOLNO       NO. VOLUMES (ENTRIES IN DOSVOLTB)
0067  103 Bitstring    1 DOSEXTNO       NO. EXTENTS (ENTRIES IN DOSEXTTB)
0068  104 Signed       4 DOSBUFSP       SIZE OF VSAM I/O BUFFER(S)
006C  108 Character    8 DOSUCNAM       VSAM USER CATALOG DDNAME
0074  116 Signed       4 DOSSAVE (6)    TEMP SAVE FOR RE-ENTRANT CODE
008C  140 Bitstring    1 DOSEXTCX       - CURRENT EXTENT (USED BY DMSXCP)
008D  141 Character    1 DOSTYPE        - DATASET TYPE (SAM=S, VSAM=A)
0090  144 Signed       4 DOSDTF         POINTER TO DTF
0094  148 Signed       4 DOSF1AD        POINTER TO F1 LABEL
          00000098       DOSCCHHR       * DOS CCHHR
0098  152 Character    2 DOSCC          DOS CC - CYLINDER
009A  154 Character    2 DOSHH          DOS HH - TRACK
009C  156 Character    1 DOSR           DOS R - RECORD
009D  157 Bitstring    1 DOSINIT2       - DOSCB flag byte 2
          1... ....      DOSOSASN       X'80' DOSOSASN OS DLBL Issued and
                                        ASSGN done.
          .1.. ....      DOSOSCLR       X'40' DOSOSCLR OS DLBL CLEAR and
                                        unASSGN needed.
009E  158 Signed       2 DOSRTRYC       DOS I/O RETRY COUNT
00A0  160 Dbl-Word     8 DOSEND (0)     END ADDRESS OF THIS BLOCK
          00000014       DOSENSIZ       (*-DOSSECT)/8 SIZE OF BLOCK IN
                                        DBLWORDS

 

DOSSECT Storage Layout

          
*** DOSSECT - DOS Simulation Control Block
*
*     +---------------------------+---------------------------+
*   0 |         DOSNEXT           |         DOSCBID           |
*     +---------------------------+---------------------------+
*   8 |                        DOSDD                          |
*     +-------------------------------------------------------+
*  10 |                        DOSOP                          |
*     +-------------------------------------------------------+
*  18 |                       DOSDSNAM                        |
*     +-------------------------------------------------------+
*  20 |                       DOSDSTYP                        |
*     +-------------+-------------+---------------------------+
*  28 |  DOSDSMD    |/////////////|         DOSBUFF           |
*     +-------------+-------------+------+------+-------------+
*  30 |         DOSBYTE           |:FORM |DOSEPL|/////////////|
*     +---------------------------+------+------+-------------+
*  38 |         DOSREAD           |         DOSITEM           |
*     +---------------------------+------+------+-------------+
*  40 |         DOSCOUT           |DOSDEV|:TAPMD|  DOSBLKSZ   |
*     +---------------------------+------+------+-------------+
*  48 |                       DOSWORK                         |
*     +------+------+------+------+---------------------------+
*  50 |DOSSYS|DOSXXX|DOSEXT|:EXTCT|         DOSOSFST          |
*     +------+------+------+------+---------------------------+
*  58 |         DOSOSDSN          |         DOSVOLTB          |
*     +---------------------------+-------------+------+------+
*  60 |         DOSEXTTB          |  DOSSENSE   |:VOLNO|:EXTNO|
*     +---------------------------+-------------+------+------+
*  68 |         DOSBUFSP          |        DOSUCNAM-          |
*     +---------------------------+---------------------------+
*  70 |          -(06C)           |                           |
*     +---------------------------+                           |
*  78 |                                                       |
*     =                       DOSSAVE                         =
*     |                           +------+------+-------------+
*  88 |                           |:EXTCX|:TYPE |/////////////|
*     +---------------------------+------+------+-------------+
*  90 |          DOSDTF           |         DOSF1AD           |
*     +-------------+-------------+------+------+-------------+
*  98 |   DOSCC     |   DOSHH     |DOSR  |:INIT2|  DOSRTRYC   |
*     +-------------+-------------+------+------+-------------+
*
*** DOSSECT - DOS Simulation Control Block

 

DOSSECT Cross Reference

Symbol         Dspl Value
-------------- ---- -----
DOSBLKSZ       0046
DOSBUFF        002C
DOSBUFSP       0068
DOSBYTE        0030
DOSCBID        0004
DOSCC          0098
DOSCCHHR       0094 00000098
DOSCMS         0000 10
DOSCOUT        0040
DOSDD          0008
DOSDDCAT       0000 08
DOSDEV         0044
DOSDOS         0000 20
DOSDSK         0044 14
DOSDSMD        0028
DOSDSNAM       0018
DOSDSTYP       0020
DOSDTF         0090
DOSDUM         0044 00
DOSEND         00A0
DOSENSIZ       00A0 00000014
DOSEPL         0035
DOSEXT         0052
DOSEXTCT       0053
DOSEXTCX       008C
DOSEXTNO       0067
DOSEXTTB       0060
DOSFORM        0034
DOSF1AD        0094
DOSHH          009A
DOSINIT        0000
DOSINIT2       009D
DOSITEM        003C
DOSJCAT        0000 02
DOSNEXT        0000
DOSOP          0010
DOSOS          0000 40
DOSOSASN       009D 80
DOSOSCLR       009D 40
DOSOSDSN       0058
DOSOSFST       0054
DOSPERM        0000 04
DOSR           009C
DOSREAD        0038
DOSRTRYC       009E
DOSSAVE        0074
DOSSENSE       0064
DOSSYS         0050
DOSTAPID       0018
DOSTAPMD       0045
DOSTYPE        008D
DOSUCAT        0000 01
DOSUCNAM       006C
DOSVOLNO       0066
DOSVOLTB       005C
DOSWORK        0048
DOSXXX         0051
DOSYSXXX       0050

This information is based on z/VM V6R1.0.
Last updated on 23 Oct 2009 at 11:00:49 EDT.
Copyright IBM Corporation, 1990, 2008