NAME
        AddIntServer -- add an interrupt server to a system server chain

   SYNOPSIS
        AddIntServer(intNum, interrupt)
                     D0-0:4  A1

        void AddIntServer(ULONG, struct interrupt *);

   FUNCTION
        This function adds a new interrupt server to a given server chain.
        The node is located on the chain in a priority dependent position.
        If this is the first server on a particular chain, interrupts will
        be enabled for that chain.

        Each link in the chain will be called in priority order until the
        chain ends or one of the servers returns with the 68000's Z condition
        code clear (indicating non-zero).  Servers on the chain should return
        with the Z flag clear if the interrupt was specifically for that
        server, and no one else.  VERTB servers should always return Z set.
        (Take care with High Level Language servers, the language may not
        have a mechanism for reliably setting the Z flag on exit).

        Servers are called with the following register conventions:

            D0 - scratch
            D1 - scratch

            A0 - scratch
            A1 - server is_Data pointer (scratch)

            A5 - jump vector register (scratch)
            A6 - scratch

            all other registers must be preserved

   INPUTS
        intNum - the Paula interrupt bit number (0 through 14). Processor
                 level seven interrupts (NMI) are encoded as intNum 15.
                 The PORTS, COPER, VERTB, EXTER and NMI interrupts are
                 set up as server chains.
        interrupt - pointer to an interrupt structure.
                 By convention, the LN_NAME of the interrupt structure must
                 point a descriptive string so that other users may
                 identify who currently has control of the interrupt.

   WARNING
        Some compilers or assemblers may optimize code in unexpected ways,
        affecting the conditions codes returned from the function.  Watch
        out for a "MOVEM" instruction (which does not affect the condition
        codes) turning into "MOVE" (which does).

   BUGS
        The graphics library's VBLANK server, and some user code, currently
        assume that address register A0 will contain a pointer to the custom
        chips. If you add a server at a priority of 10 or greater, you must
        compensate for this by providing the expected value ($DFF000).

   SEE ALSO
        remintserver(), setintvector(), hardware/intbits.i,exec/interrupts.i