Int 21 Fn 0D  - DOS 1+ - Disk Reset                                        [D]

   AH = 0Dh

Return: (DOS 6 only) CF clear (earlier versions preserve CF)

Notes: This function writes all modified disk buffers to disk, but does not
     update the directory information (that is only done when files are
     closed or a SYNC call is issued)

See Also: AX=5D01h,INT 13/AH=00h,INT 2F/AX=1120h