INT 2F - DOS 3.3+ GRAFTABL.COM - GET GRAPHICS FONT TABLE
        AX = B001h
        DS:BX -> DWORD buffer for address of 8x8 font table
Return: buffer filled
        AL = FFh
Note:   PCDOS 3.30/4.01 set the font table offset to 0130h, MSDOS 3.30 to 0030h