Function 0C2h   Pointing Device BIOS Interface      (DesQview 2.x)    (PS/2) 
entry   AH      0C2h 
	AL      00h     enable/disable 
			BH      00h    disable 
		01h     reset 
			return  BH     device ID 
		02h     set sampling rate 
			BH      00h    10/second 
			        01h    20/second 
			        02h    40/second 
			        03h    60/second 
			        04h    80/second 
			        05h    100/second 
			        06h    200/second 
		03h set resolution 
			BH     00h     one count per mm 
			       01h     two counts per mm 
			       02h     four counts per mm 
			       03h     eight counts per mm 
		04h     get type 
			return  BH      device ID 
		05h     initialize 
			BH      data package size (1 - 8 bytes) 
		06h     get/set scaling factor 
			BH      00h return device status 
			        return  BL      status byte 
			                bit 0: right button pressed 
			                bit 1: reserved 
			                bit 2: left button pressed 
			                bit 3: reserved 
			                bit 4: 0=1:1 scaling, 1=2:1 scaling 
			                bit 5: device enabled 
			                bit 6: 0=stream mode, 1=remote mode 
			                bit 7: reserved 
			                CL      resolution (see function 03h) 
			                DL      sample rate, reports per second 
			        01h     set scaling at 1:1 
			        02h     set scaling at 2:1 
		07h     set device handler address 
			ES:BX   user device handler 
			return  AL      00h 
return  CF      set on error 
	AH      status 
		00h     successful 
		01h     invalid function 
		02h     invalid input 
		03h     interface error 
		04h     need to resend 
		05h     no device handler installed 
note    The values in BH for those functions that take it as input are stored 
	in different locations for each subfunction