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


(Table 00476)
Values for APM v1.0+ battery status:
 00h	high
 01h	low
 02h	critical
 03h	charging
 FFh	unknown
 other	reserved
SeeAlso: #00477,#00478


Bitfields for APM v1.1+ battery flag:
Bit(s)	Description	(Table 00477)
 0	high
 1	low
 2	critical
 3	charging
 4	selected battery not present (APM v1.2)
 5-6	reserved (0)
 7	no system battery
Note:	all bits set (FFh) if unknown
SeeAlso: #00476,#00478


Bitfields for APM v1.1+ remaining battery life:
Bit(s)	Description	(Table 00478)
 15	time units: 0=seconds, 1=minutes
 14-0	battery life in minutes or seconds
Note:	all bits set (FFFFh) if unknown
SeeAlso: #00476,#00477