Int 13 Fn 0F  - Hard Disk - Write Sector Buffer (xt Only)                  [B]

   AH = 0Fh
   DL = drive number (80h = first, 81h = second hard disk)
   ES:BX -> buffer

Return: CF set on error
   CF clear if successful
   AH = status code (see #0166)

Notes: does not write data to the drive
   should be called before formatting to initialize an XT-type
     controller's sector buffer
   used for diagnostics only on PS/2 systems

See Also: AH=0Bh