Bringing in saves from other emulators

A report said Nintendo DS saves from Delta could not be imported. We needed to check not only the file format but also which files N-EMU accepted.

A Delta user told us they could not import their Nintendo DS save into N-EMU.

We first checked the save format. N-EMU uses melonDS for Nintendo DS. The .dsv file being imported used the DeSmuME format, which differs from N-EMU saves in its extension and the information appended at the end.

The import feature also had a limitation: it accepted N-EMU backups, not in-game save files from other apps. Saves lived in app-private storage, so users could not easily copy them there themselves. This affected other systems as well as Nintendo DS.

A DeSmuME .dsv file adds 40 bytes of metadata after the in-game save. Checking and removing that metadata yields save data N-EMU can read.

We made the import process identify the format so users do not need a separate converter. It validates and removes DeSmuME metadata when present and reads a raw save directly otherwise.

Import also checks that the file size is supported and rejects files that fail this check. Super Famicom and PSP manage saves across multiple files, so they cannot be restored from a single file and are excluded from this feature.

For supported systems and formats, you can import an in-game save from another emulator and continue playing. A report from someone actually using the app helped us improve this limitation. Thank you for reporting it.