Wolfenstein 3D on unmodified GameBoy Color uses cartridge hack

Move over DOOM! Wolfenstein 3D is now the new standard of "is it a computer?" Well, considering both games were made by the same company the same company, it's not really a competition. But DOOM has had its time in the spotlight and has been ported to almost every thing imaginable and unimaginable, and now it's Wolfenstein's time to shine. And while it might sound too simple to have Wolfenstein running on a GameBoy Color, this one is particularly intriguing because the GBC itself is unmodified. The trick is in the cartridge.

What hacker Anders "happydaze" Granlund did is nothing short of impressive. The original Game Boy Color was by no means a powerful gaming handheld. And while PCs when Wolfenstein 3D came out would be prehistoric by today's standards, they still outrun the GBC by miles. It would have probably been a piece of cake to get Wolfenstein running on a Raspberry Pi or a modded GBC, but that would mean Granlund would be messing with an otherwise pristine and perfectly preserved piece of antiquity.

What he did, instead, was to turn his attention to the cartridge. Like any GBC title, the game, of course, runs on the cartridge, but that tiny box hides more chips than normal. It basically has its own processor 48 MHz ARM processor which does all the graphics processing for the game, relieving the GBC's processor of such duties. This would somewhat be analogous to today's graphics amplifiers for gaming laptops, except each amplifier was tied to a specific cartridge and, therefore, to a specific game.

Sadly, it seems that Granlund has hit the wall of the laws of physics for now. He's already using up 128 Kb of available 128 Kb of space on the ROM, which might not fit the whole game. That said, that much already contains 3 enemy types, 10 levels from one episode, and game logic and AI. And best of all, he hasn't given up yet on the endeavor. He even made legit-looking boxes for it!

SOURCE: Anders Granlund

VIA: Reddit