NAME
        SubTime -- Subtract one time request from another.

   SYNOPSIS
        SubTime( Dest, Source )
                 A0    A1

        void SubTime( struct timeval *, struct timeval *);

   FUNCTION
        This routine subtracts one timeval structure from another.  the
        results are stored in the destination (Dest - Source -> Dest)

        A0 and A1 will be left unchanged

   INPUTS
        Dest, Source -- pointers to timeval structures.

   NOTES
        This function may be called from interrupts.

   SEE ALSO
        timer.device/addtime(),
        timer.device/cmptime()

   BUGS