Just want to add my 2 cents to this subject. I had been a PC gamer for the most part, just recently purchased a PSone b/c the price of it was so cheap. From even before I got it I heard about modchips and boot disks. I could never actually try one since I dind't have a psx. Well after I got one I went net' surfing and when I did I found a website based in Hong Kong.
www.lik-sang.com , they said they had the PS-X-Change disk, I read about it on other sites, they claimed it worked so for a totalof 21 dollars I ordered one. After I got I I started testing my backups and all but a few worked like 26 out of 30. And now I notice that the ones that didn't work were b/c they needed a patch. Now all work. I would highly reccomend the PS-X-Change boot disk to anyone.