8 Player Splitscreen in Mario Kart: Double Dash!!

Fulfilling the 8-player splitscreen dream on a GameCube classic.

— 3 minute read

I remember playing Mario Kart: Double Dash!! multiplayer on many a TV growing up. At one point, I discovered the existence of the GameCube Broadband Adapter, a rare accessory that enabled local and online network linking for a small number of games. For Mario Kart, it enabled a unique party trick: up to 8 GameCubes linked together with up to 16 players, two per kart. This was the first time Nintendo allowed all 8 positions in a race to be human-controlled. This type of setup was, and still is, fascinating to me.

Unlike Xbox, where LAN was a core part of the console, the GameCube adapter was an add-on accessory, priced at $34.95 each and requiring multiple adapters to support an actual link, which kept it out of my grasp as a child. As an adult, they are long out of production, with a price to match that status. Even if you have a few adapters in hand, they remain a clunky and difficult to coordinate option, requiring multiple GameCubes, multiple copies of the game, multiple TVs, multiple adapters, and multiple controllers.

A diagram of of LAN multiplayer with 8 GameCubes connected together via a networking hub
This complex set-up is an example Nintendo provides in the game's instruction manual.

In comes Dolphin, a mature GameCube emulator with built-in emulation of the Broadband Adapter. This is a useful solution, as it completely sidesteps the need for a real adapter, or even the need for multiple GameCubes, copies of the disc, TVs, or real GameCube controllers. I got to work trying this out for myself using my own dump of the game and managed a promising configuration where 8 instances of the emulator all networked together as expected. This enabled me to lay out all 8 screens together on one monitor, which I recorded as a proof-of-concept, as seen in my video below. Considering the increasing resolutions and dimensions of modern TVs compared to the CRTs used when the game released, this is actually quite workable.

Later that year, I linked two instances of the emulator together on a laptop and managed 8 player Mario Kart: Double Dash for real, though I didn’t have the opportunity to record the event.

As an aside, Nintendont, a GameCube ISO loader for Wii, also has support for the Broadband Adapter, emulating it over Wi-Fi and even supporting a mix of Wi-Fi and real Broadband Adapters together. This was a long-standing feature request fulfilled after lots of hard development work from FIX94 and some charitable donors who made the feature bounty worthwhile. It’s very much worth a try if you have the right hardware lying around.