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
                ES:DI buffer filled
            01h failed
Desc:   determine whether VESA BIOS extensions are present and the capabilities
          supported by the display adapter
SeeAlso: AX=4F01h,AX=7F00h
Index:  installation check;VESA

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    WORD    total amount of video memory in 64K blocks
 14h 236 BYTEs  reserved
Notes:  the list of supported video modes is stored in the reserved portion of
          the SuperVGA information record by some implementations, and it may
          thus be necessary to either copy the mode list or use a different
          buffer for all subsequent VESA calls
        the 1.1 VESA document specifies 242 reserved bytes at the end, so the
          buffer should be 262 bytes to ensure that it is not overrun

.