I've managed to get a SNES with Super Mario World from a friend of mine, but the game won't save my progress. I Googled around a bit and figured out that SNES games use a battery to save their files, and since the cartridge was old, I'd need to replace it.
So far so good, but when I opened the cartridge, I couldn't find an old battery or even space for one. Is this one different? Is it even official? How do I fix my problem?