INT 2F U - DOS 3+ internal - CANONICALIZE FILE NAME
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
SeeAlso: INT 21/AH=60h

See also: 2F1123

2F1221 - DOS 3+ internal - CANONICALIZE FILE NAME