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START                                                       CMS Nucleus command

Use the START command to begin execution of CMS, OS, or VSE programs that were
previously loaded or fetched.  The format of the START command is:
+----------+------------------------------------------------------------------+
| START    | [*|entry [args...]]                                              |
+----------+------------------------------------------------------------------+
where:

entry    passes control to the control section name or entry point name at
         execution time.  The operand, entry, may be a filename only if the
         filename is identical to a control section name or an entry point
         name.

*        passes control to the default entry point.  See the discussion of the
         LOAD command for a discussion of the default entry point selection.

args...  are arguments to be passed to the started program.  If user arguments
         are specified, the entry or * operands must be specified; otherwise,
         the first argument is taken as the entry point.  Arguments are passed
         to the program via general register 1.  The entry operand and any
         arguments become a string of doublewords, one argument per doubleword,
         and the address of the list is placed in general register 1.


Usage notes:

1.  Any undefined names or references specified in the files loaded into
    storage are defined as zero.  Thus, if there is a call or branch to a
    subroutine from a main program, and if the subroutine has never been
    loaded, the call or branch transfers control at execution time to location
    zero of the virtual machine, and this is rarely a good thing.

2.  Do not use the START command for programs that are generated via the GENMOD
    command with the NOMAP option.  The START command does not execute properly
    for such programs.

3.  When arguments are passed on the START command, the requirements of both
    CMS and the language of the application program must be met.  For example,
    COBOL programs require arguments separated by commas:
       START * A,B,C
    See the appropriate language guide for details on parameter requirements.

4.  Issue the START command immediately following the LOAD and INCLUDE
    commands.  If the LOAD and INCLUDE were issued in an EXEC procedure, issue
    the START command from within the EXEC as well.

5.  If START is issued from the virtual console or from an EXEC, register
    0 points to an extended parameter list block.  The extended parameter list
    for the START command pointed to by register 0 has the following structure:
       DC     A(EPLCMD)
       DC     A(EPLARGBG)
       DC     A(EPLARGND)
       DC     A(0)
    where:

    EPLCMD    points to the start of the command name or '*'.
    EPLARGBG  points to the start of the arguments.
    EPLARGND  points to the first byte after the arguments.

Responses:

DMSLIO740I      Execution begins ...
   is displayed when the designated entry point is validated.  This message is
   suppressed if CMS/DOS is active and the COMP option is specified in the
   FETCH command.