While you could simply pop an original PS1 disc into your console or use software emulators, running a custom PKG (package file)
For users with modified consoles, a fan-made "PS1 Classic" PKG allows the game to be installed directly to the XMB. tekken 3 pkg ps3 best
: The most stable and straightforward version is the official PlayStation 1 Classic Go to product viewer dialog for this item. While you could simply pop an original PS1