Function 6505h          Get Filename-Character Table                 DOS 3.3+

    Returns the address of the filename character table for the
    specified code page and country code. The table specifies which
    characters cannot be used in filenames (i.e. terminators).

        Entry   AX    = 6505h
                BX    = Code page ID (0FFFFh = current code page)
                CX    = Size of buffer (min. 5)
                DX    = Country code (0FFFFh = current country)
                ES:DI = Pointer to country info buffer

        Return  Buffer updated
                AX changed
                or
                AX = Error code, if CF is set
                     | 01h Invalid function (CX < 5)
                     | 02h File not found

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    Format of country info buffer:
        Offset  Size    Description
        00h     1       Info-ID (= 05h)
        01h     4       32-bit address of filename character table

    The filename character table consists of a FileCharTable structure.


    Note
    This function appears to return the same information for all
    countries and codepages; documented for DOS 5.0+.