NAME
        Debug -- run the system debugger

   SYNOPSIS
        Debug(flags)
              D0

        void Debug(ULONG);

   FUNCTION
        This function calls the system debugger.  By default this debugger
        is "SAD" in >= V39 and "ROM-WACK" in < V39.  Other debuggers are
        encouraged to take over this entry point (via setfunction()) so
        that when an application calls Debug(), the alternative debugger
        will get control.  Currently a zero is passed to allow future
        expansion.

   NOTE
        The Debug() call may be made when the system is in a questionable
        state; if you have a setfunction() patch, make few assumptions, be
        prepared for supervisor mode, and be aware of differences in the
        Motorola stack frames on the 68000,'10,'20,'30,'40 (etc.)

   BUGS
        In ROMWack, calling this function in SUPERVISOR state would have
        caused the a5 register to be trashed and the user stack pointer to
        be trashed.  As of V39 (and the instroduction of SAD) this is no
        longer the case.  However, calling this function in supervisor
        state is a bit "tricky" at best...

        Note that due to a bug, pre-V40 SAD had the command
        codes wrong.  See the SAD autodoc for more details.

   SEE ALSO
        setfunction()
        your favorite debugger's manual...
        the SAD autodocs...
        the ROM-WACK chapter of the ROM Kernel Manual... (pre-V39)