cheat device for ps1 games on ps2 system

[Jedi Master Thrash]

Are there any cheat code devices that work for ps1 games on a PS2 system?

Some of the gameshark ones supposedly work on older ps2 systems (pre 2003 models). Does anyone know for sure what the partnumber cutoff is? I've heard 35000 before. However, mine is 39001, but I'm able to play some PS1 games that other PS2s are unable to play.

But are there any devices that work on all ps2 systems?

Also, will any cheat disc (codebreaker, gameshark, or action replay) let you play imports on the PS2?

 

[ExCyber]

I think my brother has used the PS1 Code Breaker on a post-2003 PS2 successfully, but I don't clearly remember. Some older (pre-MAX) editions of PS2 Action Replay also come with a "bonus" PS1 disc.

As far as I know, there's no way to use cheat discs to play imports on PS2 except in conjunction with mods and/or questionable methods of playing with the drive door/switch mechanisms.