This is only to introduce how to modify and checksum on the gma950 vbios.
you can learn the way then cross reference to your vbios, in order to modify right parameter make machine do well.
fllow me to modify gma950 vbios

custom the display IO

custom the FPS,the parameter more little more capability

custom the display device work in 3:4(0x33 ) or 16:10 (0x73)

this is the checksum,if the checksum is wrong,it will not work any more,on some machine this error maybe deadliness.

checksum: original vbios equal to modified vbios
original：0x01 + 0x01 + 0x4A + 0x33 + 0x00 = 7F
modified：0x13 + 0x09 + 0x48 + 0x73 + 0x? = 7F

？= 007F -(13 +09 +48 +73) = A8（low）