Adding Members

To add additional members to the PDS, follow the procedure described in Figure 1. However, a separate DD statement (with the space request omitted) is required for each member. The disposition should be specified as modify (DISP=MOD). The data set must be closed and reopened each time a new member is specified on the DD statement.

You can use the basic partitioned access method (BPAM) to process more than one member without closing and reopening the data set. Use the STOW, BLDL, and FIND macros to provide more information with each directory entry, as follows:

Request space in the DD statement for the entire data set and the directory.
Define DSORG=PO or DSORG=POU in the DCB macro.
Use WRITE and CHECK to write and check the member records.
Use NOTE to note the location of any note list written within the member, if there is a note list, or to note the location of any subgroups. A note list is used to point to the beginning of each subgroup in a member.
When all the member records have been written, issue a STOW macro to enter the member name, its location pointer, and any additional data in the directory. The STOW macro writes an end-of-file mark after the member.
Continue to use the WRITE, CHECK, NOTE, and STOW macros until all the members of the data set and the directory entries have been written.

Figure 1 shows an example of using STOW to create members of a PDS.

Figure 1. Creating Members of a PDS Using STOW

   //PDSDD  DD    ---,DSN=MASTFILE,DISP=MOD,SPACE=(TRK,(100,5,7))
            ...
            OPEN  (OUTDCB,(OUTPUT))
            LA    STOWREG,STOWLIST   Load address of STOW list
            ...
 
   **   WRITE MEMBER RECORDS AND NOTE LIST
 
   MEMBER   WRITE DECBX,SF,OUTDCB,OUTAREA   WRITE  first record of member
            CHECK DECBX
            LA    NOTEREG,NOTELIST          Load address of NOTE list
   *
            WRITE DECBY,SF,OUTDCB,OUTAREA   WRITE and CHECK next record
            CHECK DECBY
   *
            NOTE  OUTDCB                  To divide the member into subgroups,
            ST    R1,0(NOTEREG)           NOTE the TTRN of the first record in
   *                                      the subgroup, storing it in the NOTE list.
            LA    NOTEREG,4(NOTEREG)      Increment to next NOTE list entry
            ...
            WRITE DECBZ,SF,OUTDCB,NOTELIST   WRITE NOTE list record at the
   *                                         end of the member
            CHECK DECBZ
            NOTE  OUTDCB                 NOTE TTRN of NOTE list record
            ST    R1,12(STOWREG)         Store TTRN in STOW list
            STOW  OUTDCB,(STOWREG),A     Enter the information in directory
   *                                     for this member after all records
   *                                     and NOTE lists are written.
            LA    STOWREG,16(STOWREG)    Increment to the next STOW list entry
            ...
Repeat from label "MEMBER" for each additional member, changing the
member name in the "STOWLIST" for each member
            ...
            CLOSE (OUTDCB)      (NO automatic STOW)
            ...
 
   OUTAREA  DS    CL80          Area to write from
   OUTDCB   DCB   ---,DSORG=PO,DDNAME=PDSDD,MACRF=W
   R1       EQU   1             Register one, return register from NOTE
   NOTEREG  EQU   4             Register to address NOTE list
   NOTELIST DS    0F            NOTE list
            DS    F             NOTE list entry  (4 byte TTRN)
            DS    19F           one entry per subgroup
   STOWREG  EQU   5             Register to address STOW list
   STOWLIST DS    0F            List of member names for STOW
            DC    CL8'MEMBERA'  Name of  member
            DS    CL3           TTR of first record (created by STOW)
            DC    X'23'         C byte, 1 user TTRN, 4 bytes of user data
            DS    CL4           TTRN of NOTE list
            ...                 one list entry per member (16 bytes each)

Recommendation: Do not use the example in Figure 1 for PDSEs. If your installation plans to convert PDSs to PDSEs, follow the procedure described in Figure 1.