AH = 29h
        DS:SI = pointer to string to parse
        ES:DI = pointer to memory to fill with unopened FCB
        AL = bit mask to control parsing
            0 = 0: parsing stops if file separator found
                1: leading separator ignored
            1 = 0: drive number in FCB set to default drive if not present
                   in string
                1: drive number in FCB not changed
            2 = 0: filename in FCB set to blanks if no filename in string
                1: filename in FCB not changed if string does not contain
                   a filename
            3 = 0: extension in FCB set to blanks if no extension in string
                1: extension left unchanged
Return: AL = 00: no wildcards in name or extension
             01: wildcards appeared
        DS:SI = pointer to first byte after parsed string
        ES:DI = unopened FCB
-----------------------------------------------------------