INT 15 - Advanced Power Management v1.0+ - GET POWER STATUS

	AX = 530Ah
	BX = device ID
	    0001h all devices power-managed by APM
	    80xxh specific battery unit number XXh (01h-FFh) (APM v1.2)
Return: CF clear if successful
	    BH = AC line status
		00h off-line
		01h on-line
		02h on backup power (APM v1.1)
		FFh unknown
		other reserved
	    BL = battery status (see #00476)
	    CH = battery flag (APM v1.1+) (see #00477)
	    CL = remaining battery life, percentage
		00h-64h (0-100) percentage of full charge
		FFh unknown
	    DX = remaining battery life, time (APM v1.1) (see #00478)
	    ---if specific battery unit specified---
	    SI = number of battery units currently installed
	CF set on error
	    AH = error code (09h,0Ah) (see #00473)
Notes:	should not be called from within a hardware interrupt handler to avoid
	  reentrance problems
	supported in real mode (INT 15) and both 16-bit and 32-bit protected
	  mode