INT 15 - SYSTEM - PROGRAMMABLE OPTION SELECT (PS50+IBM PS/2 Models 50,60,70,80)
	AH = C4h
	AL = subfunction
	    00h return base POS register address
	    01h enable selected slot for setup
		BL = slot number (1 to 8)
	    02h disable setup for all slots (enable adapter)
Return: CF set on error
	DX = base POS register address (if subfunction 00h)
SeeAlso: AH=C6h