In brief: Have you ever wanted to play Minecraft inside Minecraft? It sounds crazy, but with the "Chungus 2" project, the idea has become a reality, as players have created a way to actually play the popular sandbox game inside of itself using redstone.
Last year, Sammyuri, a Minecraft redstone builder, created a virtual computer inside Minecraft. Using the power of redstone -- one of the more advanced elements in Minecraft - they were able to build an entirely working computer, named "Chungus 2", featuring an 8-bit processor with a 1 Hz clock speed and 256 bytes of RAM. Despite the specs, it was capable of playing games such as Tetris, Snake, and Connect Four, albeit at a 32x32 resolution.
Sammyuri called upon fellow redstone builders Uwerta and StackDoubleFlow, along with some volunteers, to upgrade Chungus 2 to pull off a daunting task: playing Minecraft inside Minecraft.
Upgrading the specs of the virtual computer took over seven months for the team to finish, adding another 256 bytes of RAM, a graphics processor that they named "AMOGUS," and 6 kilobytes worth of graphics memory. All of this to display Minecraft on a virtual 96x96 resolution screen... all inside of Minecraft.
The Minecraft world running on the virtual computer consists of an 8x8x8 chunk of land featuring 16 unique blocks. Amazingly, the group of developers were able to get nearly every essential feature of Minecraft working... (yes, in Minecraft).
Mining works as intended, crafting works in both 2x2 and 3x3 forms, and chests can hold up to 10 stacks of items. Unfortunately, you cannot mine diamonds in the world, as the game caps out at iron tools. Even little things such as decaying leaves, fall damage, and gravity-affected sand are in the game.
As expected, there were some caveats to getting this virtual computer to run Minecraft. Sammyuri notes that the game runs at an approximate frame rate of "a frame every few days" without any adjustments or server changes. To make the game recognizable for viewers, the team needed to add a separate server called MCHPRS (Minecraft High Performance Redstone Server). MCHPRS speeds the game up to over 10,000x the normal speed, allowing the virtual computer to run Minecraft at a frame rate of around 0.1 FPS. And on top of that, the video is also sped up "roughly 2,000,000x times."
The sheer intelligence of these redstone developers leaves no doubt that this is a situation of "when" rather than "if" they manage to improve further on Chungus 2. Sammyuri has already confirmed that the team is planning on putting efforts towards running Doom on Chungus 2 at some point in the future (of course).
If you wish to download all of the required files to play Minecraft inside of Minecraft yourself, Sammyuri graciously links everything in the description of the embedded video above, including the MCHPRS.