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

   AH = 16h
   DL = drive number (00h-7Fh)

Return: CF clear if change line inactive
       AH = 00h (disk not changed)
   CF set if change line active
       AH = status
       01h invalid command (SyQuest)
       06h change line active or not supported
       80h drive not ready or not present

Notes: call AH=15h first to determine whether the drive supports a change
     line
   this call also clears the media-change status, so that a disk change
     is only reported once
BUG:   some versions of Award 386 Modular BIOS and AMI BIOS fail to clear
     the media-change status

See Also: AH=15h,AH=49h