11th October 2005, 7:20 AM
You can't write to a cartridge's main memory. If you could, we wouldn't have memory cards. Some carts came with EEPROM (like OoT and most Nintendo published games), but that is physically a different piece of memory with a completely different technology. Like lazy said, the Game Shark alters what the game stores in the console's RAM, but that can never get onto your cartridge and will be erased after you power off. You could, perhaps, ruin a memory card of the EEPROM saved data (you could possibly even corrupt the EEPROM so that nothing can be saved to it) but you won't ever alter the actual game code.
I am not 100% certain on how NES games worked either, but I find it doubtful that they could be written to either. It is more expensive to do a read/write memory file system than read only (look at CD writers and CD-RWs compared to standard CD players) and I don't think Nintendo would do that for kicks. Perhaps the EEPROM chip was corrupted and that made the game unsavable, but it should never be unplayable.
I am not 100% certain on how NES games worked either, but I find it doubtful that they could be written to either. It is more expensive to do a read/write memory file system than read only (look at CD writers and CD-RWs compared to standard CD players) and I don't think Nintendo would do that for kicks. Perhaps the EEPROM chip was corrupted and that made the game unsavable, but it should never be unplayable.