Int 2F Fn 1221  U - DOS 3+ Internal - Canonicalize File Name               [D]

   AX = 1221h
   DS:SI -> file name to be fully qualified
   ES:DI -> 128-byte buffer for resulting canonical file name
   SS = DOS DS (must be using a DOS internal stack)

Return: (see INT 21/AH=60h)

Note:  identical to INT 21/AH=60h

See Also: AX=1123h,INT 21/AH=60h