Building a Fully Functional 3D Minecraft Computer Inside Vanilla Minecraft

Since the first redstone CPU appeared in Minecraft, a meme has circulated that one day redstone engineers will be able to play Minecraft inside Minecraft; that day has finally arrived.

The project, dubbed “My Computer,” features a 1 Hz CPU, 8 KB of RAM, a 6 KB video memory GPU, a 96×96‑pixel display, and a PS4 controller as input, all built with vanilla redstone.

Running the computer is demonstrated in the following animation:

To execute game code, the developers first wrote programs in the intermediate language URCL, then compiled them to custom assembly for the in‑game CPU.

After ten months of work by three people, they achieved an “epic nesting” – a fully playable Minecraft that includes world generation, block placement, mining, and even crafting.

CPU and GPU are self‑made

Sammyuri spent seven months hand‑crafting a custom 8‑bit RISC CPU named CHUNGUS 2 , operating at 1 Hz with 256 bytes of RAM and a three‑register instruction set.

Alongside the CPU, a dedicated assembler translates programs into block structures that can be pasted directly into the Minecraft world.

The GPU, called AMOGUS (Absurdly Massive Operator on Graphics), handles 3D rendering by transforming world coordinates into screen pixels, performing texture mapping, depth testing, and rasterisation.

Texture mapping is a key step in GPU‑based 3D rendering: each screen pixel is linked to a location on a 3D object's texture, and the mapping changes as the camera moves.

Besides graphics, the computer stores game data in ROM (e.g., crafting recipes) and a 256‑byte RAM map for the world, addressed by (x, y, z) coordinates.

Input is handled via a series of pressure plates that act as a controller, sending button states to a queue that the CPU reads.

Because redstone is slow, the team used the MCHPRS server to accelerate signal propagation, achieving a maximum of 0.1 frames per second.

Despite the low frame rate, the two‑minute showcase video required about nine hours of recording, illustrating the massive effort involved.

How hard is it?

Previous attempts used mods or external browsers; this project relies solely on vanilla Minecraft, adding an extra layer of “hardcore” challenge.

The CPU features a four‑stage pipeline, 64‑byte 8‑way associative cache, branch prediction, and complies with RISC principles, while the GPU successfully renders the entire world in 3D.

The achievement demonstrates Minecraft’s Turing‑completeness, showing that “Minecraft inside Minecraft” can be recursively nested, though each nesting reduces the world size.

Future work includes optimizing the GUI, creating a redstone‑only version, and possibly running DOOM inside Minecraft.

For those interested, the source code is available on GitHub, and a compressed package of the 3D Minecraft‑in‑Minecraft build can be downloaded from Mediafire.

Reference links and further reading are listed at the end of the original article.