FSCBD

Prolog  

Control Block Contents  
   FSCBD DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

FSCBD Prolog

 NAME       : FSCBD
 Description: File System Control Block
 DSECT      : FSCBD
 Function   : Maps a based structure which names
              all fields within an FSCB. FSCBD is a PLIST
              defined for general use by routines that use
              the CMS file system. FSCBD is generated when
              the user issues the FSCBD macro.

FSCBD Control Block Content

FSCBD DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      FSCBD          File System Control Block
0000    0 Character    8 FSCBCOMM       File system command (e.g. RDBUF)
0008    8 Character   18 FSCBFILE       File ID (name, type, and mode)
0008    8 Character   16 FSCBFNFT       File name and file type
0008    8 Character    8 FSCBFN         File name
0010   16 Character    8 FSCBFT         File type
0018   24 Character    2 FSCBFM         File mode (letter and number)
0018   24 Character    1 FSCBFML        File mode letter
0019   25 Character    1 FSCBFMN        File mode number
001A   26 Signed       2 FSCBITNO       Relative record number to be
                                        accessed on FSREAD and FSWRITE
                                        (applies only to the non-extended
                                        FSCB)
001C   28 Address      4 FSCBBUFF       Address of the input/output
                                        buffer for FSREAD and FSWRITE
                                        (also used on calls to DMSSTT for
                                        the FST address)
0020   32 Signed       4 FSCBSIZE       Length (in bytes) of the
                                        input/output buffer (also used to
                                        return the record length on
                                        FSOPEN)
0024   36 Character    2 FSCBFV         Record format and first flag byte
0024   36 Character    1 FSCBRECF       Record format - F or V
0025   37 Bitstring    1 FSCBFLG        First flag byte
     'FSCBFLG' flag byte definition
          1... ....      FSCBTHEX       X'80' Space threshold exceeded
                                        (SFS only)
          .1.. ....      FSCBITAV       X'40' Item available (CDF only)
          ..1. ....      FSCBEPL        X'20' Extended PLIST (FORM=E)
          ...1 ....      FSCBMSG        X'10' MSG=YES on FSSTATE or
                                        FSOPEN
          .... 1...      FSCBSTW        X'08' STATEW specified on FSSTATE
          .... .1..      FSCBCACY       X'04' CACHE=YES specified
          .... ..1.      FSCBCACN       X'02' CACHE=NO specified
          .... ...1      FSCBRCAV       X'01' Previous record null (CDF
                                        only)
0026   38 Signed       2 FSCBNOIT       Number of records to be accessed
                                        on FSREAD and FSWRITE (applies
                                        only to the non-extended FSCB)
0026   38 Bitstring    1 FSCBFLG2       Second flag byte
     'FSCBFLG2' flag byte definition (FORM=E only)
          1... ....      FSCBNMAC       X'80' NOMSG=ACTIVE specified on
                                        FSOPEN
          .1.. ....      FSCBNMNF       X'40' NOMSG=NOTFOUND specified on
                                        FSOPEN
          ..1. ....      FSCBNMOS       X'20' NOMSG=OSDOS specified on
                                        FSOPEN
0027   39 Character    1 FSCBOTYP       OPENTYP value
     'FSCBOTYP' Values (FORM=E only)
          .... ....      FSCBTNON       X'00' OPENTYP=NONE specified
          000000D9       FSCBTRD        C'R' OPENTYP=READ specified
          000000E6       FSCBTWR        C'W' OPENTYP=WRITE specified
          000000D5       FSCBTNEW       C'N' OPENTYP=NEW specified
          000000E7       FSCBTREP       C'X' OPENTYP=REPLACE specified
0028   40 Signed       4 FSCBNORD       Number of bytes actually read on
                                        FSREAD
     'FSCBFST' is returned on FSOPEN. Its value is based on the OPENTYP
     specified and whether or not the file exists. Note that a non-extended
     format FSCB (FORM=E not specified) implies OPENTYP=NONE. The values are
     as follows:
  File doesn't exist .... FSCBFST=A(0)
     File exists: Not FORM=E ............ FSCBFST=A(Copy of 40 byte FST)
     OPENTYP=NONE .......... FSCBFST=A(Copy of 64 byte FST) OPENTYP=READ
     .......... FSCBFST=A(Copy of 64 byte FST) OPENTYP=WRITE .........
     FSCBFST=A(Copy of 64 byte FST) OPENTYP=REPLACE ....... FSCBFST=A(-1)
     OPENTYP=NEW ........... Error, FSCBFST is unchanged
0028   40 Address      4 FSCBFST        Address of a copy of the FST
                                        returned on FSOPEN
     The following fields apply only to the extended form FSCB (i.e., FORM=E
     was specified).
002C   44 Signed       4 FSCBAITN       Relative record number to be
                                        accessed on FSREAD and FSWRITE
                                        (also referred to as the
                                        "alternate item number")
0030   48 Signed       4 FSCBANIT       Number of records to be accessed
                                        on FSREAD and FSWRITE (also
                                        referred to as the "alternate
                                        number of items")
0034   52 Signed       4 FSCBWPTR       Extended write pointer (input on
                                        FSPOINT FORM=E, output on FSOPEN)
0038   56 Signed       4 FSCBRPTR       Extended read pointer (input on
                                        FSPOINT FORM=E, output on FSOPEN)
          0000003C       FSCBLNBY       *-FSCBD Length (in bytes) of the
                                        extended FSCB

FSCBD Storage Layout

          
*** FSCBD - File System Control Block
*
*     +-------------------------------------------------------+
*   0 |                       FSCBCOMM                        |
*     +-------------------------------------------------------+
*   8 |                                                       |
*     =                       FSCBFILE                        =
*     |             +-----------------------------------------+
*     |             | 1A
*     +-------------+
*
*** FSCBD - File System Control Block
          
*** Overlay for FSCBFILE in FSCBD
*
*     +-------------------------------------------------------+
*   8 |                       FSCBFNFT                        |
*     |                                                       |
*     +-------------------------------------------------------+
*  18
*
*** Overlay for FSCBFILE in FSCBD
          
*** Overlay for FSCBFNFT in FSCBD
*
*     +-------------------------------------------------------+
*   8 |                        FSCBFN                         |
*     +-------------------------------------------------------+
*  10 |                        FSCBFT                         |
*     +-------------+-----------------------------------------+
*  18 |   FSCBFM    | 1A
*     +-------------+
*
*** Overlay for FSCBFNFT in FSCBD
          
*** Overlay for FSCBFM in FSCBD
*
*     +------+------+-------------+---------------------------+
*  18 |:BFML |:BFMN |  FSCBITNO   |         FSCBBUFF          |
*     +------+------+-------------+-------------+-------------+
*  20 |         FSCBSIZE          |   FSCBFV    | 26
*     +---------------------------+-------------+
*
*** Overlay for FSCBFM in FSCBD
          
*** Overlay for FSCBFV in FSCBD
*
*                                 +------+------+-------------+
*  20 ...                      24 |:BRECF|:BFLG |  FSCBNOIT   |
*                                 +------+------+-------------+
*  28
*
*** Overlay for FSCBFV in FSCBD
          
*** Overlay for FSCBNOIT in FSCBD
*
*                                               +------+------+
*  20 ...                                    26 |:BFLG2|:BOTYP|
*     +---------------------------+-------------+------+------+
*  28 |         FSCBNORD          | 2C
*     +---------------------------+
*
*** Overlay for FSCBNOIT in FSCBD
          
*** Overlay for FSCBNORD in FSCBD
*
*     +---------------------------+---------------------------+
*  28 |         FSCBFST           |         FSCBAITN          |
*     +---------------------------+---------------------------+
*  30 |         FSCBANIT          |         FSCBWPTR          |
*     +---------------------------+---------------------------+
*  38 |         FSCBRPTR          | 3C
*     +---------------------------+
*
*** Overlay for FSCBNORD in FSCBD

FSCBD Cross Reference

Symbol         Dspl Value
-------------- ---- -----
FSCBAITN       002C
FSCBANIT       0030
FSCBBUFF       001C
FSCBCACN       0025 02
FSCBCACY       0025 04
FSCBCOMM       0000
FSCBEPL        0025 20
FSCBFILE       0008
FSCBFLG        0025
FSCBFLG2       0026
FSCBFM         0018
FSCBFML        0018
FSCBFMN        0019
FSCBFN         0008
FSCBFNFT       0008
FSCBFST        0028
FSCBFT         0010
FSCBFV         0024
FSCBITAV       0025 40
FSCBITNO       001A
FSCBLNBY       0038 0000003C
FSCBMSG        0025 10
FSCBNMAC       0026 80
FSCBNMNF       0026 40
FSCBNMOS       0026 20
FSCBNOIT       0026
FSCBNORD       0028
FSCBOTYP       0027
FSCBRCAV       0025 01
FSCBRECF       0024
FSCBRPTR       0038
FSCBSIZE       0020
FSCBSTW        0025 08
FSCBTHEX       0025 80
FSCBTNEW       0027 000000D5
FSCBTNON       0027 00
FSCBTRD        0027 000000D9
FSCBTREP       0027 000000E7
FSCBTWR        0027 000000E6
FSCBWPTR       0034