INT 10 - VIDEO - Video7 VGA,VEGA VGA,HP Ext BIOS - INSTALLATION CHECK
        AX = 6F00h
        BX = 0000h
Return: BX = 5637h ('V7') indicates Video7 VGA/VEGA VGA extensions are present
        BX = 4850h ('HP') indicates HP Extended BIOS video functions present
SeeAlso: AX=6F01h,AX=6F02h,AX=6F03h,AX=6F04h,AX=6F05h

.