Function 01h	Get Status of disk system
entry   AH      01h 
	DL      drive (hard disk if bit 7 set) 
return  AL      status of most recent operation 
		00h     successful completion 
		01h     bad command 
		02h     address mark not found 
		03h     tried to write on write-protected disk 
		04h     sector not found 
		05h     reset failed (hard disk) 
		06h     diskette removed or changed 
		07h     bad parameter table (hard disk) 
		08h     DMA overrun 
		09h     attempt to DMA across 64K boundary 
		0Ah     bad sector detected (hard disk) 
		0Bh     bad track detected (hard disk) 
		0Ch     unsupported track 
		0Dh     invalid number of sectors on format (hard disk) 
		0Eh     control data address mark detected (hard disk) 
		0Fh     DMA arbitration error (hard disk) 
		10h     bad CRC/EEC on read 
		11h     data ECC corrected 
Function 01h	Get Status of disk system
return  AL      status of most recent operation
                20h     controller failure 
		40h     seek failed 
		80h     timeout 
		0AAh    drive not ready (hard disk) 
		0BBh    undefined error (hard disk) 
		0CCh    write fault     (hard disk) 
		0E0h    status error    (hard disk) 
		0FFh	sense operation failed (hard disk)