As psx_paul say knife trick is the only option without mod chip..
But let me tell u a story:
A week ago my friend get a ps2 v5 board and decided to use knife trick with AR2 (which cost him £30.00)and boot the back up game without mod chip so he can save couple of £££££.Couple of days later he sold his ps2 for £50.00 because he damage the try..
So ask yourself its worth it!!!
GET A MOD CHIP Its worth very penny...