How can you play older versions of games on a newer machine

Unless the console says that it plays older games on the Box that it came in you can not. It also needs to name the platforms that it will play the games of. The PS3 will play most PS1 titles because they are easy to emulate, but the PS2 is very difficult to emulate and has many games that add to the problem and the new PS3 Consoles do not play them. Emulation will become a even bigger when new PS3 and Xbox 360 consoles are released although the new not yet released Wii U is supposed to be able to play Wii games and use Wii accessories. Sometimes even older PC games will not work on th newer windows operating systems so the problem is not unique to the game consoles.