DVD to CDR

[solid7x2]

I recently installed my ps2 no solder v4-5 modchip. It works fine, and I was able to use some known working backups, and I backed up a CD game (Street fighter EX3) without patching and it worked. I was told it is possible to back up dvd games and put them onto a CD if the game is small enough. I tried a direct copy and it did not work. There are plenty of wierd tutorials that all say something different, and none specify if the games are cd or dvd.

help appreciated, thanks