Programming Interface Information: This page documents intended Programming Interfaces that allow the customer to write programs to obtain the services of z/VM.

#### FCBSECT

Prolog

Control Block Contents
FCBSECT DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### FCBSECT Prolog

     Name       : CMSCB
     Description: Simulated OS Control Blocks
     DSECT      : FCBSECT
     Function   : FCBSECT consists of the CMS file control block
                  (FCB) used for file management under CMS, the
                  simulated OS job file control block (JFCB),
                  input/output block (IOB), and data extent block
                  (DEB). FCBSECT is dynamically allocated from
                  CMS free storage each time the FILEDEF command
                  is issued.

#### FCBSECT Control Block Content

#### FCBSECT DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      FCBSECT        Simulated OS Control Blocks
    0000    0 Bitstring    1 FCBINIT (0)    - INTERESTING TIDBITS
              .... 1...      FCBOPCB        X'08' - OPEN ACQUIRED THIS CMS
                                            BLOCK
              .... .1..      FCBPERM        X'04' - PERMANENT CONTROL BLOCK
              .... ..1.      FCBBATCH       X'02' - SPECIAL BATCH DATA SET
              .... ...1      FCBCATML       X'01' - CONCATENATED MACLIB DATA
                                            SET
              ...1 ....      FCBOS          X'10' FCB FOR OS FORMATTED DISK
              ..1. ....      FCBDOSL        X'20' CONCATENATED DOSLIB DATA
                                            SET
              .1.. ....      FCBCATLD       X'40' CONCATENATED OS LOADLIB
              1... ....      FCBDID         X'80' ASSOCIATE DDNAME WITH
                                            ENTIRE DISK FOR DISKID USAGE
    0000    0 Address      4 FCBNEXT        - AL3(NEXT CMSCB)
    0004    4 Address      4 FCBPROC        - A(SPECIAL PROCESSING ROUTINE)
    0008    8 Character    8 FCBDD          - DATA DEFINITION NAME
    0010   16 Character    8 FCBOP          - CMS OPERATION
    0018   24 Dbl-Word     8 IHAJFCB (0)    - *** JOB FILE CONTROL BLOCK ***
    0018   24 Bitstring    1 JFCBDSNM (0)   - 44 BYTES, DATA SET NAME
    0018   24 Character    8 FCBDSNAM       - DATA SET NAME
    0020   32 Character    8 FCBDSTYP       - DATA SET TYPE
              ..1. .1..      FCBPRPU        FCBDSTYP+4 - PRINTER/PUNCH
                                            COMMAND LIST
    0028   40 Bitstring    1 FCBTBSP (0)    2 BYTES, TAPE BACKSPCE COUNT
    0028   40 Character    2 FCBDSMD        - DATA SET MODE
    002A   42 Character    2 FCBDSMDC       - Saved concat data set mode
    002C   44 Signed       4 FCBBUFF        - A(INPUT-OUTPUT BUFFER)
    0030   48 Signed       4 FCBBYTE        - DATA COUNT
    0034   52 Character    1 FCBFORM        - FILE FORMAT: FIXED/VARIABLE
                                            RECS
    0035   53 Bitstring    1 FCBFLG         - =FSCBFLG flag byte for extended
                                            plist bit
    0036   54 Bitstring    1 FCBFLG2        - =FSCBFLG2 extended plist flag
                                            byte
    0037   55 Bitstring    1 FCBOTYP        - OPEN intent (R,W,X,N)
    0038   56 Signed       4 FCBREAD        - N'BYTES ACTUALLY READ
    003C   60 Signed       4 FCBITEM        - EXTENDED PLIST ITEM COUNT.
    0040   64 Signed       4 FCBCOUT        - EX. PLIST RECORDS / PHYSICAL
                                            BLK.
    0044   68 Signed       4 FCBWPTR        - EXTENDED PLIST WRITE PTR.
    0048   72 Signed       4 FCBRPTR        - EXTENDED PLIST READ PTR.
    004C   76 Bitstring    1 FCBDEV         - DEVICE TYPE CODE
              .... ....      FCBDUM         0 - DUMMY DEVICE
              .... .1..      FCBPTR         4 - PRINTER
              .... 1...      FCBRDR         8 - READER
              .... 11..      FCBCON         12 - CONSOLE TERMINAL
              ...1 ....      FCBTAP         16 - TAPE
              ...1 .1..      FCBDSK         20 - DISK
              ...1 1...      FCBPCH         24 - PUNCH
              ...1 11..      FCBCRT         28 - CRT
              ..1. ....      FCBVSAM        32 - VSAM
    004D   77 Bitstring    1 FCBRFMT        - --> Working Recording Format
                                            FCBRFMT is defined for a tape
                                            file only. It is a TAPEIO
                                            recording format code denoting
                                            the recording format in effect
                                            with the file. While no file is
                                            open, it simply reflects the
                                            recording format request from the
                                            FILEDEF, which may be a
                                            nonspecific recording format
                                            code. While a file is open,
                                            though, it is always a specific
                                            recording format code -- the one
                                            indicated by the FILEDEF
                                            specification in conjunction with
                                            the capabilities of the device.
                                            See also FCBOFMT.
    004E   78 Bitstring    1 FCBOFMT        --> Original Recording Format
                                            FBCOFMT is defined only for a
                                            tape file. It is set by DMSFLO
                                            when the Filedef command is
                                            issued and should NEVER be
                                            changed anywhere else. This means
                                            that we can ALWAYS restore the
                                            original recording format after
                                            it has been changed. When the
                                            tape file is not open,
                                            FCBRFMT=FCBOFMT unless an Open
                                            error occurred, in which case the
                                            value of FCBRFMT is
                                            unpredictable.
    004F   79 Bitstring    1 *              - RESERVED
    0050   80 Signed       2 FCBRECL        - DCB LRECL AT OPEN TIME
    0052   82 Bitstring    1 IOBIOFLG       - I/O FLAGS
    0053   83 Bitstring    1 FCBDCBCT       - NO. OF DCB'S USING THIS FCB
    0054   84 Signed       4 FCBR13         - SAVEAREA VECTOR R13
    0058   88 Address      4 FCBKEYS        - A(DDS IN'CORE KEY TABLE)
    005C   92 Address      4 FCBPDS         - A(PDS IN-CORE DIRECTORY)
    0060   96 Bitstring    1 JFCBMASK (8)   - VARIOUS MASK BITS
    0068  104 Character    1 JFCBCRDT (3)   - DATA SET CREATION DATE (YDD)
    006B  107 Character    1 JFCBXPDT (3)   - DATA SET EXPIRATION DATE (YDD)
    006E  110 Bitstring    1 JFCBIND1       - INDICATOR ONE
    006F  111 Bitstring    1 JFCBIND2       - INDICATOR TWO
              1... ....      JFCMOD         X'80' - DISP MOD specified on
                                            FILEDEF command.
              .1.. ....      JFCOLDF        X'40' - DISP OLD ON FILEDEF
              .... 1...      JFCLRCLX       X'08' - LRECL=X specified/implied
              .... .1..      JFCLIBSV       X'04' - Lib Dataserver usage
                                            noted by OPEN (CMS usage differs
                                            from OS/MVS)
              .... ..1.      JFCEXTND       X'02' - EXTEND specified on OPEN
                                            macro (This flag is used only for
                                            the duration of OPEN processing -
                                            CMS usage differs from OS/MVS)
              .... ...1      JFCM4FLG       X'01' - This is a filemode number
                                            4 file (CMS usage differs from
                                            OS/MVS)
    0070  112 Bitstring    1 JFCBUFNO       - NUMBER OF BUFFERS
    0071  113 Bitstring    1 JFCBFTEK (0)   - BUFFERING TECHNIQUE
    0071  113 Bitstring    1 JFCBFALN       - BUFFER ALIGNMENT
    0072  114 Signed       2 JFCBUFL        - BUFFER LENGTH
    0074  116 Bitstring    1 JFCEROPT       - ERROR OPTION
    0075  117 Bitstring    1 JFCKEYLE       - KEYLENGTH
    0076  118 Bitstring    1 *              - ---NOT USED---
    0077  119 Bitstring    1 JFCLIMCT (3)   - BDAM SEARCH LIMIT
    007A  122 Bitstring    1 FCBDSORG (0)   - DATA SET ORGANIZATION
    007A  122 Bitstring    1 JFCDSORG (2)   -
    007C  124 Bitstring    1 FCBRECFM (0)   - RECORD FORMAT
    007C  124 Bitstring    1 JFCRECFM       -
    007D  125 Bitstring    1 JFCOPTCD       - OPTION CODES
    007E  126 Signed       2 FCBBLKSZ (0)   - BLOCK SIZE
    007E  126 Signed       2 JFCBLKSI       -
    0080  128 Signed       2 FCBLRECL (0)   - LOGICAL RECORD LENGTH
    0080  128 Signed       2 JFCLRECL       -
    0082  130 Bitstring    1 FCBIOSW        - I/O OPERATION INDICATOR
              1... ....      FCBCLOSE       X'80' - DURING "CLOSE"
              .1.. ....      FCBMASTR       X'40' - Master FCB for
                                            Concatenation
              ..1. ....      FCBPROCC       X'20' - GOTO FCBPROC DURING CLOSE
              ...1 ....      FCBPROCO       X'10' - GOTO FCBPROC DURING OPEN
              .... 1...      FCBCASE        X'08' - ON=LOWER CASE CONSOLE I/O
              .... .1..      FCBPVMB        X'04' - PUT-MOVE-VAR-BLK
              .... ..1.      FCBIOWR        X'02' - WRITE/PUT
              .... ...1      FCBIORD        X'01' - READ/GET
    0083  131 Bitstring    1 FCBIOSW2       - I/O OPERATION INDICATORS
              .... ...1      FCBMVPDS       X'01' - SW FOR MOVEFILE WITH PDS
                                            OPTION
              .... ..1.      FCBMMV         X'02' MOVE PDS SWITCH FOR FIND
              .... .1..      FCBBYSVC       X'04' The function currently in
                                            control was invoked via SVC. Used
                                            by routines that are called
                                            during FEOV processing.
              .... 1...      FCBMVFIL       X'08' Movefile is active
              ...1 ....      FCBCLEAV       X'10' - LEAVE positioning on
                                            Close
              ..1. ....      FCBCRERD       X'20' - REREAD positioning on
                                            Close
              .1.. ....      FCBTCLOS       X'40' A CLOSE TYPE T was done
              1... ....      FCBWRTSW       X'80' INDICATE DCB OPEN FOR WRITE
    0084  132 Bitstring    1 DEBLNGTH (0)   - L'DEB IN DBLW WORDS
    0084  132 Signed       4 *              - ---NOT USED---
    0088  136 Dbl-Word     8 IHADEB (0)     - *** DATA EXTENT BLOCK ***
    0088  136 Address      4 DEBTCBAD       - A(MOVE-MODE USER BUFFER)
    008C  140 Signed       4 SEBSAV         DYNAMIC SAVE FOR RET ADDR FOR SEB
                                            (OS I/O SIM)
    0090  144 Bitstring    1 DEBOFLGS (4)   - DATA SET STAUS FLAGS
    0094  148 Bitstring    1 DEBOPATB (4)   - OPEN/CLOSE OPTION BYTE
    0098  152 Bitstring    1 IOBFLG (0)     - (START OF IOBPREFIX FOR NORMAL
                                            SCH)
              .... ....      IOBBFLG        0 - DISPLACEMENT OF IOB FLAG IN
                                            IOB
              .1.. ....      IOBOUT         X'40' - "WRITE,PUT" IN PROGRESS
              ..1. ....      IOBIN          X'20' - "READ,GET" IN PROGRESS
              ...1 ....      IOBUPD         X'10' - "QSAM PUTX" IN PROCESS
    0098  152 Address      4 IOBNXTAD       - A(NEXT BUFFER TO BE USED)
    009C  156 Signed       4 IOBECB         - ECB FOR QSAM NORMAL SCHEDULING
    00A0  160 Signed       4 IHAIOB (0)     - *** INPUT/OUTPUT BLOCK ***
    00A0  160 Bitstring    1 DEBDEBID (0)   - DEB IDENTIFICATION
    00A0  160 Address      4 DEBDCBAD       - A(DATA CONTROL BLOCK)
    00A4  164 Bitstring    1 IOBECBCC (0)   - ECB COMPLETION CODE
              .... 11..      IOBBECBC       12 - DISPLACEMENT OF ECB CODE IN
                                            IOB
              .... 11..      IOBBECBP       12 - DISPLACEMENT OF ECB PTR IN
                                            IOB
    00A4  164 Address      4 IOBECBPT       - A(EVENT CONTROL BLOCK)
    00A8  168 Bitstring    1 IOBFLAG3 (0)   - I/O ERROR FLAG
              ...1 ....      IOBBCSW        16 - DISPLACEMENT OF CSW IN IOB
    00A8  168 Bitstring    1 IOBCSW (8)     - LAST CCW STORED(I.E., RESIDUAL
                                            COUNT)
    00B0  176 Address      4 IOBSTART       - X'ID-NEXT BUFFER',AL3(INITIAL
                                            BUFFER)
    00B4  180 Address      4 IOBDCBPT       - A(DATA CONTROL BLOCK)
    00B8  184 Bitstring    1 IOBEND (0)     - END-OF-INPUT/OUTPUT BLOCK
    00B8  184 Signed       4 FCBMEMBR (2)   OS PDS MEMBER NAME
    00C0  192 Signed       4 FCBOSFST       POINTER TO OS FST
    00C4  196 Signed       4 FCBOSDSN       POINTER TO OS DSNAME BLOCK
    00C8  200 Signed       4 FCBXTENT       - NUMBER OF ITEMS IN EXTENT
    00CC  204 Address      4 FCBTEOV        - ADDRESS OF TEOVEXIT ROUTINE.
    00D0  208 Address      4 FCBTSAVE       - ADDRESS OF SYSTEM REGISTER SAVE
                                            AREA FOR TEOVEXIT.
    00D4  212 Bitstring    1 FCBFLAG1       - MISC. FLAG BITS.
              1... ....      FCBTEOVS       X'80' TAPE END-OF-VOLUME EXIT
                                            AVAILABLE
              .1.. ....      FCBTEOVA       X'40' TEOV EXIT IS ACTIVE.
              ..1. ....      FCBMVOL        X'20' PROCESSING MULTIVOLUME FILE
              ...1 ....      FCBVSECT       X'10' PROCESSING VOLIDS FROM A
                                            VOLSECT
              .... 1...      FCBMTCAN       X'08' TAPE MOUNT CANCELED FROM
                                            DMSTVS Bits used for SFS
                                            directory-resident files:
              .... .1..      FCBSPCHK       X'04' FSWRITE tracks file's SFS
                                            filespace usage
              .... ..1.      FCBDIR         X'02' this file is on an SFS
                                            directory
              .... ...1      FCBERASE       X'01' erase file when it is
                                            closed: this flag is used ONLY
                                            for SFS directory files
    00D5  213 Bitstring    1 FCBVCTR        - VOLID COUNTER The following
                                            field has two uses: It used as
                                            the volume sequence number for
                                            tape and as the original
                                            blocksize saved by DMSSOP for
                                            Console
    00D6  214 Signed       2 FCBVSEQ        TAPE VOLUME SEQUENCE NUMBER
              11.1 .11.      FCBCNBLK       FCBVSEQ Console Original
                                            Blocksize
    00D8  216 Signed       4 FCBALT         ALTERNATE TAPE DRIVE TAPID Or
                                            temp save of fcbosfst for dmssop
    00DC  220 Address      4 FCBTVIPL       DMSTVI PLIST ADDRESS
    00E0  224 Address      4 FCBSYSPA       SYSPARM STRING ADDRESS
    00E4  228 Signed       2 FCBSYSPL       SYSPARM STRING LENGTH (DWORDS)
    00E6  230 Signed       2 FCBSYSPB       SYSPARM STRING LENGTH (BYTES)
              1... 1...      FCBDISP        IHADEB-FCBINIT Displacement of
                                            FCB address
    00E8  232 Bitstring    1 FCBFLAG3       -
              1... ....      FCBFMAST       X'80' FCB filemode was asterisk
              .1.. ....      FCBUSASI       X'40' Buffer Offset Flag bit for
                                            ANSI DMSSOP will define an FCB
                                            for any required global library
                                            if the user has not defined one.
                                            When the DCB is closed DMSOSC
                                            checks this flag to decide
                                            whether to clear the FCB
              ..1. ....      FCBSCLR        X'20' Do Filedef SCLEAR for this
                                            DDNAME
              ...1 ....      FCBLIBSV       X'10' Use RMS to call Tape
                                            Library Dataserver
              .... 1...      FCBLRCLX       X'08' LRECL=X specified in
                                            FILEDEF
              .... .1..      FCBLRCLM       X'04' OPEN FCBMERGE reset the
                                            DCBLRECL
              .... ..1.      FCBRDEOF       X'02' Read a CMS LIB to physical
                                            EOF
              .... ...1      FCBOSSIM       X'01' File needs true OS Sim
                                            limits
    00E9  233 Bitstring    1 FCBBUFOF       - BUFFER OFFSET (0-99) FOR ANSI
    00EA  234 Bitstring    1 FCBRSRV1       RESERVED for future use
    00EB  235 Bitstring    1 FCBLBOM        Saved first char of dataset name
    00EC  236 Signed       4 FCBVCOUT       Number of variable length records
                                            read into a block by QSAM
    00F0  240 Bitstring    1 FCBFLAG4       -
              1... ....      FCBTXTL        X'80' CONCATENATED TXTLIB DATA
                                            SET
              .1.. ....      FCBLRI         X'40' Logical Record Interface
                                            used
              ..1. ....      FCBBADDN       X'20' Fileid matches, DDN doesn't
              ...1 ....      FCBLRIXT       X'10' Xtended LRI records in use
              .... 1...      FCBDRFMT       X'08' Default RECFM filled in by
                                            OPEN
              .... .1..      FCBDLREC       X'04' Default LRECL filled in by
                                            OPEN
              .... ..1.      FCBDBLKZ       X'02' Default BLKSZ filled in by
                                            OPEN
              .... ...1      FCBDBUFO       X'01' Default BUFOF filled in by
                                            OPEN
    00F1  241 Bitstring    1 FCBFLAG5       -
              1... ....      FCBMACL        X'80' CMS MACLIB DATA SET
              .1.. ....      FCBCMDOS       X'40' CMS DOSLIB DATA SET
    00F2  242 Bitstring    1 FCBRSRV2 (2)   RESERVED for future use
    00F4  244 Signed       4 FCBAIC         Number input recs in FST at OPEN
    00F8  248 Character    4 FCBPRIME       PRIME TAPE ID ENTERED AT FILEDEF
    00FC  252 Address      4 FCBNEXTC       Address of the next FCB in the
                                            concatenation, or zero if none
    0100  256 Signed       2 FCBFSEQ        Tape File Sequence counter
    0102  258 Signed       2 *              Reserved for future use
    0104  260 Signed       4 FCBFWVAL       Fullword work field
    0108  264 Dbl-Word     8 FCBEND (0)     - END-OF FCB,JFCB,DEB,IOB BLOCKS
              00000021       FCBENSIZ       (*-FCBSECT)/8 - SIZE OF FCB
                                            ENTRY, DOUBLEWORDS
                 SPECIAL FIELDS FOR TAPE FILES ONLY
    0018   24 Character    4 FCBTAPID       TAPE IDENTIFICATION
    001C   28 Bitstring    1 FCBLABT        TAPE LABEL TYPE
              .... ....      FCBOFF         X'00' NO LABEL PROCESSING AT ALL
              .... ...1      FCBBLP         X'01' BYPASS LABELS - JUST
                                            POSITION TAPE
              .... ..1.      FCBSL          X'02' IBM STANDARD LABELS
              .... .1..      FCBUSER        X'04' USER STANDARD LABELS
              .... .11.      FCBSUL         FCBSL+FCBUSER IBM AND USER
                                            STANDARD LABELS
              .... 1...      FCBNSL         X'08' NONSTANDARD USER LABELS
              ...1 ....      FCBNSLMD       X'10' NSL ROUTINE IS A MODULE
              ..1. ....      FCBNL          X'20' NO LABELS
              .1.. ....      FCBAL          X'40' ANSI LABELS
              .1.. .1..      FCBAUL         FCBAL+FCBUSER ANSI AND USER
                                            STANDARD LABELS
    001D   29 Bitstring    1 FCBTPSW        TAPE SWITCH
              1... ....      FCBLEAVE       X'80' DO NOT REPOSITION TAPE FOR
                                            OPEN
              .1.. ....      FCBNOEOV       X'40' DO NOT DO ANY EOV
                                            PROCESSING AT ALL
              ..1. ....      FCBFVLEV       X'20' LEAVE specified on FEOV
                                            macro
              ...1 ....      FCBFVREW       X'10' REWIND specified on FEOV
                                            macro
              .... 1...      FCBFEOV        X'08' FEOV was issued on the
                                            current tape volume. This flag is
                                            set on during FEOV and turned off
                                            either at CLOSE time or when a
                                            new tape volume is mounted.
              .... .1..      FCBKEEP        X'04' DISP KEEP specified in
                                            Filedef X'02' Reserved
    001E   30 Signed       2 FCBPOS         POSITION PARAMETER
    0020   32 Character    8 FCBNSLNM       NSL ROUTINE NAME
    00B8  184 Address      4 FCBLABPT       POINTER TO LABSECT
    00BC  188 Signed       4 FCBBLKCT       BLOCK COUNT FOR TAPE FILE
    0024   36 Character    8 FCBIOOUT       - SPECIAL I/O COMMAND LIST
    002C   44 Address      4 FCBIOBUF       - A(DATA BUFFER)
    0030   48 Character    1 FCBCONCR       - CONSOLE COLOR CODE
    0031   49 Bitstring    1 FCBCONMS       - CONSOLE MISCELLANEOUS INFO
    0032   50 Signed       2 FCBIOCNT       - L'DATA BUFFER
            DATA EVENT CONTROL BLOCK

#### FCBSECT Storage Layout

    *** FCBSECT - Simulated OS Control Blocks
    *
    *     +---------------------------+---------------------------+
    *   0 |         FCBNEXT           |         FCBPROC           |
    *     +---------------------------+---------------------------+
    *   8 |                        FCBDD                          |
    *     +-------------------------------------------------------+
    *  10 |                        FCBOP                          |
    *     +-------------------------------------------------------+
    *  18 |                       FCBDSNAM                        |
    *     +-------------------------------------------------------+
    *  20 |                       FCBDSTYP                        |
    *     +-------------+-------------+---------------------------+
    *  28 |  FCBDSMD    |  FCBDSMDC   |         FCBBUFF           |
    *     +-------------+-------------+------+------+------+------+
    *  30 |         FCBBYTE           |:FORM |FCBFLG|:FLG2 |:OTYP |
    *     +---------------------------+------+------+------+------+
    *  38 |         FCBREAD           |         FCBITEM           |
    *     +---------------------------+---------------------------+
    *  40 |         FCBCOUT           |         FCBWPTR           |
    *     +---------------------------+------+------+------+------+
    *  48 |         FCBRPTR           |FCBDEV|:RFMT |:OFMT |//////|
    *     +-------------+------+------+------+------+------+------+
    *  50 |  FCBRECL    |:IOFLG|:DCBCT|          FCBR13           |
    *     +-------------+------+------+---------------------------+
    *  58 |         FCBKEYS           |          FCBPDS           |
    *     +---------------------------+---------------------------+
    *  60 |                       JFCBMASK                        |
    *     +--------------------+--------------------+------+------+
    *  68 |     JFCBCRDT       |     JFCBXPDT       |:BIND1|:BIND2|
    *     +------+------+------+------+------+------+------+------+
    *  70 |:BUFNO|:BFALN|  JFCBUFL    |:EROPT|:KEYLE|//////|(077)-|
    *     +------+------+-------------+------+------+------+------+
    *  78 | -JFCLIMCT   |  JFCDSORG   |:RECFM|:OPTCD|  JFCBLKSI   |
    *     +-------------+------+------+------+------+-------------+
    *  80 |  JFCLRECL   |:IOSW |:IOSW2|///////////////////////////|
    *     +-------------+------+------+---------------------------+
    *  88 |         DEBTCBAD          |          SEBSAV           |
    *     +---------------------------+---------------------------+
    *  90 |         DEBOFLGS          |         DEBOPATB          |
    *     +---------------------------+---------------------------+
    *  98 |         IOBNXTAD          |          IOBECB           |
    *     +---------------------------+---------------------------+
    *  A0 |         DEBDCBAD          |         IOBECBPT          |
    *     +---------------------------+---------------------------+
    *  A8 |                        IOBCSW                         |
    *     +---------------------------+---------------------------+
    *  B0 |         IOBSTART          |         IOBDCBPT          |
    *     +---------------------------+---------------------------+
    *  B8 |                       FCBMEMBR                        |
    *     +---------------------------+---------------------------+
    *  C0 |         FCBOSFST          |         FCBOSDSN          |
    *     +---------------------------+---------------------------+
    *  C8 |         FCBXTENT          |         FCBTEOV           |
    *     +---------------------------+------+------+-------------+
    *  D0 |         FCBTSAVE          |:FLAG1|:VCTR |  FCBVSEQ    |
    *     +---------------------------+------+------+-------------+
    *  D8 |          FCBALT           |         FCBTVIPL          |
    *     +---------------------------+-------------+-------------+
    *  E0 |         FCBSYSPA          |  FCBSYSPL   |  FCBSYSPB   |
    *     +------+------+------+------+-------------+-------------+
    *  E8 |:FLAG3|:BUFOF|:RSRV1|:LBOM |         FCBVCOUT          |
    *     +------+------+------+------+---------------------------+
    *  F0 |:FLAG4|:FLAG5|  FCBRSRV2   |          FCBAIC           |
    *     +------+------+-------------+---------------------------+
    *  F8 |         FCBPRIME          |         FCBNEXTC          |
    *     +-------------+-------------+---------------------------+
    * 100 |  FCBFSEQ    |/////////////|         FCBFWVAL          |
    *     +-------------+-------------+---------------------------+
    *
    *** FCBSECT - Simulated OS Control Blocks

    *** Overlay for FCBDSNAM in FCBSECT
    *
    *     +---------------------------+------+------+-------------+
    *  18 |         FCBTAPID          |:LABT |:TPSW |   FCBPOS    |
    *     +---------------------------+------+------+-------------+
    *  20 |                       FCBNSLNM                        |
    *     +-------------------------------------------------------+
    *  28
    *
    *** Overlay for FCBDSNAM in FCBSECT

    *** Overlay for FCBMEMBR in FCBSECT
    *
    *     +---------------------------+---------------------------+
    *  B8 |         FCBLABPT          |         FCBBLKCT          |
    *     +---------------------------+---------------------------+
    *  C0
    *
    *** Overlay for FCBMEMBR in FCBSECT

    *** Overlay for FCBDSTYP+4 in FCBSECT
    *
    *                                 +---------------------------+
    *     ...                      24 |        FCBIOOUT-          |
    *     +---------------------------+---------------------------+
    *  28 |          -(024)           |         FCBIOBUF          |
    *     +------+------+-------------+---------------------------+
    *  30 |:CONCR|:CONMS|  FCBIOCNT   | 34
    *     +------+------+-------------+
    *
    *** Overlay for FCBDSTYP+4 in FCBSECT

#### FCBSECT Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    DEBDCBAD       00A0
    DEBDEBID       00A0
    DEBLNGTH       0084
    DEBOFLGS       0090
    DEBOPATB       0094
    DEBTCBAD       0088
    FCBAIC         00F4
    FCBAL          001C 40
    FCBALT         00D8
    FCBAUL         001C 44
    FCBBADDN       00F0 20
    FCBBATCH       0000 02
    FCBBLKCT       00BC
    FCBBLKSZ       007E
    FCBBLP         001C 01
    FCBBUFF        002C
    FCBBUFOF       00E9
    FCBBYSVC       0083 04
    FCBBYTE        0030
    FCBCASE        0082 08
    FCBCATLD       0000 40
    FCBCATML       0000 01
    FCBCLEAV       0083 10
    FCBCLOSE       0082 80
    FCBCMDOS       00F1 40
    FCBCNBLK       00D6 D6
    FCBCON         004C 0C
    FCBCONCR       0030
    FCBCONMS       0031
    FCBCOUT        0040
    FCBCRERD       0083 20
    FCBCRT         004C 1C
    FCBDBLKZ       00F0 02
    FCBDBUFO       00F0 01
    FCBDCBCT       0053
    FCBDD          0008
    FCBDEV         004C
    FCBDID         0000 80
    FCBDIR         00D4 02
    FCBDISP        00E6 88
    FCBDLREC       00F0 04
    FCBDOSL        0000 20
    FCBDRFMT       00F0 08
    FCBDSK         004C 14
    FCBDSMD        0028
    FCBDSMDC       002A
    FCBDSNAM       0018
    FCBDSORG       007A
    FCBDSTYP       0020
    FCBDUM         004C 00
    FCBEND         0108
    FCBENSIZ       0108 00000021
    FCBERASE       00D4 01
    FCBFEOV        001D 08
    FCBFLAG1       00D4
    FCBFLAG3       00E8
    FCBFLAG4       00F0
    FCBFLAG5       00F1
    FCBFLG         0035
    FCBFLG2        0036
    FCBFMAST       00E8 80
    FCBFORM        0034
    FCBFSEQ        0100
    FCBFVLEV       001D 20
    FCBFVREW       001D 10
    FCBFWVAL       0104
    FCBINIT        0000
    FCBIOBUF       002C
    FCBIOCNT       0032
    FCBIOOUT       0024
    FCBIORD        0082 01
    FCBIOSW        0082
    FCBIOSW2       0083
    FCBIOWR        0082 02
    FCBITEM        003C
    FCBKEEP        001D 04
    FCBKEYS        0058
    FCBLABPT       00B8
    FCBLABT        001C
    FCBLBOM        00EB
    FCBLEAVE       001D 80
    FCBLIBSV       00E8 10
    FCBLRCLM       00E8 04
    FCBLRCLX       00E8 08
    FCBLRECL       0080
    FCBLRI         00F0 40
    FCBLRIXT       00F0 10
    FCBMACL        00F1 80
    FCBMASTR       0082 40
    FCBMEMBR       00B8
    FCBMMV         0083 02
    FCBMTCAN       00D4 08
    FCBMVFIL       0083 08
    FCBMVOL        00D4 20
    FCBMVPDS       0083 01
    FCBNEXT        0000
    FCBNEXTC       00FC
    FCBNL          001C 20
    FCBNOEOV       001D 40
    FCBNSL         001C 08
    FCBNSLMD       001C 10
    FCBNSLNM       0020
    FCBOFF         001C 00
    FCBOFMT        004E
    FCBOP          0010
    FCBOPCB        0000 08
    FCBOS          0000 10
    FCBOSDSN       00C4
    FCBOSFST       00C0
    FCBOSSIM       00E8 01
    FCBOTYP        0037
    FCBPCH         004C 18
    FCBPDS         005C
    FCBPERM        0000 04
    FCBPOS         001E
    FCBPRIME       00F8
    FCBPROC        0004
    FCBPROCC       0082 20
    FCBPROCO       0082 10
    FCBPRPU        0020 24
    FCBPTR         004C 04
    FCBPVMB        0082 04
    FCBRDEOF       00E8 02
    FCBRDR         004C 08
    FCBREAD        0038
    FCBRECFM       007C
    FCBRECL        0050
    FCBRFMT        004D
    FCBRPTR        0048
    FCBRSRV1       00EA
    FCBRSRV2       00F2
    FCBR13         0054
    FCBSCLR        00E8 20
    FCBSL          001C 02
    FCBSPCHK       00D4 04
    FCBSUL         001C 06
    FCBSYSPA       00E0
    FCBSYSPB       00E6
    FCBSYSPL       00E4
    FCBTAP         004C 10
    FCBTAPID       0018
    FCBTBSP        0028
    FCBTCLOS       0083 40
    FCBTEOV        00CC
    FCBTEOVA       00D4 40
    FCBTEOVS       00D4 80
    FCBTPSW        001D
    FCBTSAVE       00D0
    FCBTVIPL       00DC
    FCBTXTL        00F0 80
    FCBUSASI       00E8 40
    FCBUSER        001C 04
    FCBVCOUT       00EC
    FCBVCTR        00D5
    FCBVSAM        004C 20
    FCBVSECT       00D4 10
    FCBVSEQ        00D6
    FCBWPTR        0044
    FCBWRTSW       0083 80
    FCBXTENT       00C8
    IHADEB         0088
    IHAIOB         00A0
    IHAJFCB        0018
    IOBBCSW        00A8 10
    IOBBECBC       00A4 0C
    IOBBECBP       00A4 0C
    IOBBFLG        0098 00
    IOBCSW         00A8
    IOBDCBPT       00B4
    IOBECB         009C
    IOBECBCC       00A4
    IOBECBPT       00A4
    IOBEND         00B8
    IOBFLAG3       00A8
    IOBFLG         0098
    IOBIN          0098 20
    IOBIOFLG       0052
    IOBNXTAD       0098
    IOBOUT         0098 40
    IOBSTART       00B0
    IOBUPD         0098 10
    JFCBCRDT       0068
    JFCBDSNM       0018
    JFCBFALN       0071
    JFCBFTEK       0071
    JFCBIND1       006E
    JFCBIND2       006F
    JFCBLKSI       007E
    JFCBMASK       0060
    JFCBUFL        0072
    JFCBUFNO       0070
    JFCBXPDT       006B
    JFCDSORG       007A
    JFCEROPT       0074
    JFCEXTND       006F 02
    JFCKEYLE       0075
    JFCLIBSV       006F 04
    JFCLIMCT       0077
    JFCLRCLX       006F 08
    JFCLRECL       0080
    JFCMOD         006F 80
    JFCM4FLG       006F 01
    JFCOLDF        006F 40
    JFCOPTCD       007D
    JFCRECFM       007C
    SEBSAV         008C

This information is based on z/VM V5R2.0.
Last updated on 6 Dec 2005 at 15:38:56 EDT.
Copyright IBM Corporation, 1990, 2005