INT 10 - VESA SuperVGA BIOS - GET SuperVGA INFORMATION
        AX = 4F00h
        ES:DI -> 256-byte buffer for SuperVGA information (see below)
Return: AL = 4Fh function supported
        AH = status
            00h successful
            01h failed
SeeAlso: AX=7F00h

Format of SuperVGA information:
Offset  Size    Description
 00h  4 BYTEs   signature ('VESA')
 04h    WORD    VESA version number
 06h    DWORD   pointer to OEM name
                "761295520" for ATI
 0Ah  4 BYTEs   capabilities
 0Eh    DWORD   pointer to list of supported VESA and OEM video modes
                (list of words terminated with FFFFh)
 12h 238 BYTEs  reserved