INT 15 U - HP 100LX/200LX - GET MAIN BATTERY LEVEL                              
	AX = 6000h
Return: AX = battery level
Note:	multiply the returned value with 1Bh and add 622h to get millivolts
SeeAlso: AX=6001h,AX=6002h,AX=6003h,AX=6004h