Bridging Game Worlds With The ‘Impossible’ Pokémon Trade

Transferring hard-earned Pokémon out of the second generation GameBoy game worlds into the ‘Advance Era’ cartridges (and vice versa) has never been officially supported by Nintendo, however [Goppier] has made these illicit trades slightly easier for budding Pokémon trainers by way of a custom PCB and a healthy dose of reverse engineering.

Changes to the data structure between Generation II on the original GameBoy (Pokémon Gold, Silver and Crystal) and Generation III on the GameBoy Advance (Pokémon Ruby, Sapphire, FireRed, LeafGreen and Emerald) meant that trades between these cartridges was never a possibility – at least not through any legitimate means. In contrast, Pokémon trades are possible between the first and second generation games, as well as from Generation III and beyond, leaving the leap from Gen II to Gen III as an obvious missing link.

Modern players have already overcome this limitation by dumping the cartridge save files onto a PC, at which point any Pokémon could be added or subtracted from the save. Thus, this method relies on self-control as well as the right hardware. [Goppier]’s solution is arguably far more elegant, and requires very little extra hardware. A simple PCB with ports for older and newer GameBoy Game Link Cables is the physical bridge between the generations. An ARM Cortex microcontroller sits between these connections and translates the game data between the old and the new.

The microcontroller is required to translate the data structure between the generations, and seems fit for purpose. Not only does the Pokémon data require conversion, but a few other hacks are needed before the two generations will talk nicely to each other. Pokémon on the GameBoy Advance brought in new features such as representing player movement in the trading rooms (i.e. you can see the other player moving on your screen), which also had to be addressed.

The concern over the legitimacy of trades within the Pokémon community is a curious, yet understandable, byproduct of the multiplayer experience. As an example, modern players have to be wary of ‘hacked’ Pokémon, which can often introduce glitches into their game world following a trade. Apart from these issues, some Pokémon players simply desire genuine Pokémon as part of fostering a fair and enjoyable gaming experience.

This literal bridge between Gen II and Gen III game worlds brings the community tantalizingly close to a ‘legitimate’ means of transferring their Pokémon out of ancient cartridges and into modern games. Could Nintendo one day officially sanction Gen II to Gen III trades with a similar device? Crazier things have happened.

We love our GameBoy hacks here on Hackaday, so why not check out this project that replaces the battery-backed SRAM in your GameBoy games with FRAM?