INT 13 - Seagate ST01/ST02 - SCSI Bus Parity

	AX = 5506h
	DL = drive ID (80h, 81h, ...)
	DH = subfunction
	    00h disable parity check
	    01h enable parity check
	    02h return current parity setting
Return: AL = status
	    00h parity checking disabled
	    01h parity checking enabled