Int 13 Fn 16  - Floppy Disk - Detect Disk Change (xt 1/10/86 Or Later,xt2  [B]

   AH = 16h
   DL = drive number

Return: CF clear if change line inactive
       AH = 00h (disk not changed)
   CF set if change line active
       AH = status
       06h change line active or not supported
       80h drive not ready or not present

Note:  call AH=15h first to determine whether the drive supports a change
     line

See Also: AH=15h