PlayStation One region mod?

[omnedon]

I fully realize that this is often done by using a "chip mod" that also allows the use of backups. I do not want to do that.

I have a specific customer, who runs a specialty import game software/old games store. He wants to know if I can do what I've done for his saturns (switched region mod) for a Playstation.

When I do a Google, I get buried in a torrent of modchip info. Is there a way? Even a chipped way that does not allow the use of backups?

I'm looking for a non game shark, permanent hardware modification solution. Any help is appreciated, even if it means confirmation that it isn't possible.

[MrKitt]

there are commercial action replay style dongle devices that you can attach and allow other regions to play on a PSX but this require the coder port .
otherwise you might install a normal 12C509 chip since if hes only interested in running legit stuff he wont use the chip for any other purpose.

chips can be bought and hex found for them at maxking www.maxking.co.uk