Function 07h	Hard Disk - format the drive starting at the desired track
		(PC2, PC-XT and Portable)
entry   AH      07h 
	AL      interleave value (XT only) (01h-10h)  
	CH      cylinder number (bits 8,9 in high bits of CL) (00h-03FFh) 
	CL      sector number 
	DH      head number (0-7) 
	DL      drive number (80h-87h, 80h=C, 81h=D,...) 
	ES:BX   format buffer, size = 512 bytes 
		the first 2*(sectors/track) bytes contain f,n for each sector 
		f=00h for good sector  
		  80h for bad sector 
		n=sector number 
return  AH      status code (see above) 
note    Award AT BIOS routines are extended to handle more than 1024 cylinders. 
	AL      number of sectors 
	CH      cylinder numberm low 8 bits 
	CL      sector number bits 0-5, bits 6-7 are high 2 cylinder bits 
	DH	head number (bits 0-5) bits 6-7 are extended high cylinders
		  (cylinder numbers greater than 1024)
	DL      drive number (0-1 for diskette, 80h-81h for hard disk) 
	ES:BX   transfer address