Hello friends.
I see this topic and maybe I can help.
The bios can´t be modified,but not have too much informations in the bios,this informations are intercepted and modified for the modchips.
But per example,the lens changer only it modifies an other chip called mexacom or mecacom,in this chip have all informations about the console,model,color system,dvd region, JAP or US or PAL system,graphic interface and so much things more. This informations can be changed with a little programming board linked in PC. Some peoples in the world have this board or the schematics to build an one,but to build you need an expensive microcontroller. I don´t know if in this chip you can to modify informations to run games without modchip,but I know that you can play any regions of dvd movies or games without problems. I found a person that have the schematics,but in principle it doesn´t want to sell nor to buy the microcontroller. I´m desperated because with this I can win so much money. I don´t know if this is possible,but imagine modify the graphic interface and install some apps in the console,run mp3, divx etc.. to function direct. hahae If anyone have the schematics plz share with US.
Saludo.