This is truly amazing.

Comment from one of the creators;

This build does NOT run in real time. It runs on MCHPRS, the server developed by StackDoubleFlow, which speeds up the game roughly 10-20,000x while running redstone. That brings the framerate to a much more reasonable 0.1fps, so the long timelapses in the video only took 9 hours to record in in total.

I worked on a CPU in Minecraft years ago and designed it to be a 7-bit CPU. I chose that number because it gave me the an appreciable number of operations plus space for arguments. I had only 6 bytes of RAM and about 32bytes of ROM. The ROM was just a circle of transparent blocks (zero) and solid blocks (one) pushed around by pistons.

The whole thing was real slow, but it was so much fun trying to design something that would perform interesting calculations. I stopped working on it as at the time Minecraft had some odd bugs with pistons that would cause non-deterministic behavior.

I think the most challenging aspect wasn't the programming or circuits, which were well understood and mapped out, but trying to create modules I could copy-paste inside a special Minecraft save editor to make the machine quickly, then manually dragging out data/command lines to hook the modules together.

I wonder if it's possible to run this outside of Minecraft in some way. I assume the developers weren't debugging the program in Minecraft itself.

My son has gotten into designing logic circuit with Redstone. I wish I could get him to do the same with 74xx/54xx parts.

Cool! Now build it in Turing Complete and export it to an FPGA

I like that part about the bees at the beginning. Also, the CPU definitely did blow my mind. Amazing work by the builder!

Did you mean to link to the video?

Derp: here is the video link: https://www.youtube.com/watch?v=-BP7DhHTU-I

@dang can you update this post to link to the video?

Pretty cool.

The program itself was written in an existing intermediate language called URCL, which was then compiled to CHUNGUS2 assembly. CHUNGUS2 is the processor made with Minecraft's redstone mechanics. The processor was emulated for development, but the demo is running on MCHPRS, a Minecraft server that uses Wasmtime's Cranelift to JIT the redstone operations, which are represented as a weighted directed graph. Before MCHPRS optimizing redstone performance using compiler techniques was not thought to be possible. With MCHPRS the demo takes 9 hours to run, it would take decades using Minecraft.

https://github.com/sammyuri/minecraft

https://github.com/MCHPR/MCHPRS

The video description says:

> 3D Minecraft in Minecraft with no command blocks, no datapacks and no mods. Features include an 8x8x8 fully 3D-rendered world with 16 different block types, 32 different items, and dozens of game mechanics including mining, crafting, smelting, building, chests, random ticks

Is "3D Minecraft" a Minecraft clone for low-powered hardware? It looks like their emulated CPU only has <10KB RAM and a 96x64 display, which screams "TI-83 program" to me.

Now it's time for the next step: build another CPU inside that one.

I think we will see more of these amazing Minecraft technical creations as people who played Minecraft as children are now finishing up their higher educations.

Incredible. Next do Minecraft in Minecraft in Minecraft.

What's with the code?

I don't know much about Minecraft, but I assumed the CPU would be built purely from blocks which act like transistors. Yet there's a part of the video where the show code written in-game(?). What's up with that? Isn't it cheating?

Don't miss the other video showing the overview of the CPU, it's seriously impressive: https://youtube.com/watch?v=FDiapbD0Xfg

This is exactly the type of content I hope to see when I check HN. Awesome.

If you like to ponder physiological implications and deeper themes of such worlds in worlds and what it can mean, in a fun way, I recommend the (sci-fi) book Permutation City (Greg Egan), from 1994. It also contains an artificial world, called the Autoverse that felt to me like Minecraft when I read the story. But it is taken a lot further...

Can someone explain to a clueless person (me) how a 1Hz CPU manages to achieve even 0.1fps frame rates. That is only ten clock cycles per frame. I don't know what the IPC of Chungus 2 is but that doesn't seem a lot of cycles to calculate each new frame.

Thinking about this another way. Real world CPUs have clock speeds at least 1 billion times faster than this and they only run Minecraft a few 1000 times faster than is claimed here. How do these numbers add up?

Nick Bostrom is silently smiling somewhere.

Reminds me of Conway’s Game of Life, emulated inside Conway’s Game of Life:

https://m.youtube.com/watch?v=xP5-iIeKXE8

The 0.1fps time scale makes no difference to people living within this minecraft universe. From their perspective a second is a second and a day is a day. Funny.

See Greg Egan's PERMUTATION CITY for more on that.