How hackers changed the ending of Zelda Ocarine of Time on Nintendo 64

If you were born in the 90s, chances are you’ve played at least once Ocarina of Time. Released in 1998 in Europe, this installment in the series Zelda was phenomenally successful with its successful transition of the kingdom of Hyrule from 2D to 3D. The title was so striking that it was entitled to a reissue on 3DS in 2011. But did you know that it was possible to discover an alternative ending to the original 64 game, or rather to create another ending from scratch?

To do this, there is no need to examine the cartridge, solder accessories to your Nintendo 64 or tamper with the heart of the game via an emulator. All you need are four 64 controllers, an original game cartridge, and a few years of programming experience. Easy !

One console, four controllers, one robot

In a video posted on the occasion of the SGDQ 2022 (a charity festival hosted by video game personalities), a team of hackers showed how they managed to modify bits of the game’s code on the fly to create missing sequences of the original title. By exploiting a bug in the game and using four controllers connected to a machine specially configured for speedrun (the practice of finishing a game as quickly as possible), it is possible to modify the numerical value of certain objects present in the game to turn them into something else altogether. We can then explore certain regions of the game early, modify dialogues and even insert characters normally absent from the game. A cutscene with Zelda and Link in version Breath of the Wild was even incorporated into the game.

Technically, the method employed is fascinating. By performing a very specific series of actions, in a very specific order, it is somehow possible to “break” the game and inject custom code into the console’s memory. Once the programming interface is made accessible, controllers 2, 3 and 4 controlled by TasBOT (the speedrun machine) will send commands which will be interpreted by the console as modifications to the game code. By rewriting code on the fly and at blazing speed, TasBOT will load the console’s RAM memory with code not necessarily present in the cartridge. This makes it possible to create new game sequences, or to dig into resources present on the cartridge, but hidden during “normal” use of the game.

Technically endless possibilities

From there, everything becomes almost possible, since by modifying the numerical values ​​assigned to an object or a character, we are able to transform them as we wish (within the limits of the capabilities of the N64). Because this is the real feat of this hack: everything happens on the console. The code certainly requires a machine that will generate code very quickly, but the information is transmitted via the controller ports and interpreted by the console. Point of hacking the source code or modding here: everything happens in real time. One could thus imagine 1001 adventures created on the fly in the world ofOcarina of Time.

“This is an original unmodified copy of Ocarina of Time and a genuine original N64. We didn’t modify anything about the game in advance. All we did was press buttons on four controllers very quickly and very precisely with the help of TasBOT. It’s Ocarina of Time in its original version, but with lots of bugs and lots of exploits for those bugs“, explains one of the team members during the presentation.

Of course, manipulation has its limits. Leaving the scenario coded by TasBOT will cause the program to crash irreparably. But the possibilities offered by this bug, and the fact that it technically requires nothing more than a console and four controllers, leave you speechless.