Minecraft is a game about building things that runs on your computer. One man is building a working computer inside the game that runs on his computer. At this point it's okay if your head explodes.
YouTube user TheInternetFTW is well on his way to creating a gigantic working 16-bit computer inside the confines of the popular sandbox game Minecraft. In this video he demonstrates a city-sized, fully-functional arithmetic logic unit, or ALU. The ALU is one of the fundamental building blocks of a central processing unit (CPU), responsible for performing arithmetic and logical operations.