what exactly does a 'no mod' patch do?

[phud]

It sounds like it makes the particular ps2 release bootable without the aid of a mod chip or any swap trick....I am finding this hard to believe and am wondering what it's real purpose is. thanks.

[Charlie]

Can't be done. The PS2 has to boot first and that is where the "secret" things are done by Sony to read pressed areas of the original game (that normal readers/burners can't reach) in order to check authenticity.

Certain modchips, like Messiah, fool the PS2 into thinking that it has properly read the CD/DVD and provided the correct booting data to allow the game to be loaded.