"Bills travel through the mail at twice the speed of checks"
Mod chips are small chips that you attach to a the PSX mainboard. They will instantly verify all checks the cds send. For example, if your computer is European, American, Japanese, if your cd is a orginal psx cd not a backup. This will make it possible for you to play American games on European playstations and use backups of your original cds. It's all really smooth and neat and here I will supply you with a couple of links to where you can get a mod chip and if you're feeling technical also how to install one yourself.