INT 21 - DOS 3.3+ - SET GLOBAL CODE PAGE TABLE
        AX = 6602h
        BX = active code page
            437 US
            850 Multilingual
            852 Slavic/Latin II (DOS 5+)
            857 Turkish
            860 Portugal
            861 Iceland
            863 Canada (French)
            865 Norway/Denmark
        DX = system code page (active page at boot time)
Return: CF set on error
            AX = error code (see AH=59h)
        CF clear if successful