INT 33 - MS MOUSE v3.0+ - EXCHANGE INTERRUPT SUBROUTINES                        
	AX = 0014h
	CX = call mask (see #03171)
	ES:DX -> FAR routine
Return: CX = call mask of previous interrupt routine
	ES:DX = FAR address of previous interrupt routine
SeeAlso: AX=000Ch,AX=0018h
                                                                                

INT 33 - CuteMouse 2.1b4+ - Exchange User Interrupt Routines                    
        AX = 0014h

Notes:  on entry, bit 7 of CX (call mask) indicates that the user routine
        will be called on a wheel movement.
        the user routine will be called with BH holding the 8-bit signed
        counter of wheel movement since the last call to the routine.