INT 33 - MS MOUSE v6.0+ - SOFTWARE RESET                                        
	AX = 0021h
Return: AX = status
	    FFFFh if mouse driver installed
		BX = number of buttons (FFFFh = two buttons)
	    0021h if mouse driver not installed
Note:	this call is identical to funtion 00h, but does not reset the mouse
SeeAlso: AX=0000h