Tulunk Village

I remember being being told once that the save data most likely has a checksum to check if the information in the save file isn't corrupted.

Does anyone know what checksum information looks like and how it is generated?

Many different types of checksums exist. For instance, all Game Boy carts require a checksum in the cartridge header, offset 0x14D, which is checked when the Game Boy is turned on. Generally a checksum is just one or two bytes generated by a simple algorithm such as adding all the bytes together (though it is certainly possible to use stronger algorithms for tasks that need it).