Function 06h	Hard Disk - format track and set bad sector flags
		(PC2, PC-XT, and Portable)
entry   AH      06h 
	AL      interleave value (XT only) 
	CH      cylinder number (bits 8,9 in high bits of CL) 
	CL      sector number 
	DH      head 
	DL      drive 
	ES:BX   512 byte format buffer 
		the first 2*(sectors/track) bytes contain f,n for each sector 
		   f  00Fh for good sector  
		      80h for bad sector 
		   n  sector number 
return  AH      status code