What kind of sav file that is accepted on slot2?

[Max Kirk]

In my phone i have John Gba Emulator and My Boy
the thing is, that can their sav files can be read on slot2?

[Exophase]

The save file has to be raw without any header or footer. I couldn't tell if you that's what John GBA uses or not, you'd have to ask their developers.

[Steak_Typhoon]

You could use a Hex Editor to compare a couple of saves and remove a header manually. But I recommend you just try the file with Drastic before you agonize about it.

[Exophase]

One hint could be the file size.

If it's an exact power of two it almost definitely doesn't have a header or footer. If it's not it may or may not.

[SSUPII]

My Boy uses raw .sav files, Jhon GBA uses a personal way to save game data