DOSSECT Back to Index page
 
Prolog 
Control Block Contents 
   DOSSECT 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.


  DOSSECT Prolog Top of page
 
 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 Top of page
 

 DOSSECT DSECT Top of page
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 Top of page
 
          
*** 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 Top of page
 
 
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 7.3.0 Last updated on 22 Jun 2022 at 16:01:11 EDT.
Copyright IBM Corporation, 1990, 2022