INT 13 - HARD DISK - WRITE SECTOR BUFFER (XT only)
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 AH=01h)
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: 130B

130F - HARD DISK - WRITE SECTOR BUFFER (XT only)