: Click the "Apply patch" button. If successful, the software will modify the file or create a new "patched" version that you can play in an emulator. Compatibility and Mobile Alternatives Delta Patcher is highly sensitive to the version of the original ROM. If the patch was designed for a US version of a game and you use a European version, the patcher will typically throw an error or the game will fail to load. Reddit +1 For users on mobile devices, there are alternative methods: 11 sites YouTube
If you need a "paper" to understand the coding logic: delta rom patcher