The Enable Broadcast Trapping routine enables the trapping of
    broadcast messages.

    Format

      SMG$SET_BROADCAST_TRAPPING  pasteboard-id [,AST-routine]

                                  [,AST-argument]

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2  –  Arguments

 pasteboard-id

    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Specifies the pasteboard for which broadcast messages are to be
    trapped. The pasteboard-id argument is the address of an unsigned
    longword that contains the pasteboard identifier.

    The pasteboard identifier is returned by SMG$CREATE_PASTEBOARD.

 AST-routine

    OpenVMS usage:ast_procedure
    type:         procedure value
    access:       read only
    mechanism:    by value

    The address of an AST routine to be called when a message is
    received at the pasteboard. The AST-routine argument is the
    address of the routine's procedure value.

    When the AST-routine argument is either omitted or is given a
    value of 0, the BROADCAST mode is set to synchronize. In this
    mode, you must periodically call SMG$GET_BROADCAST_MESSAGE to see
    if any broadcast messages have arrived.

    The AST routine is called with five parameters: AST-argument, R0,
    R1, PC, and PSL (on VAX systems) or PS (on Alpha systems).

 AST-argument

    OpenVMS usage:user_arg
    type:         longword (unsigned)
    access:       read only
    mechanism:    by value

    A value to be passed to the AST routine. The AST-argument is an
    unsigned longword that contains the value to be passed to the AST
    routine.