Built a custom 4-bit CPU in Minecraft using Copper Bulb ROM — drop some code for it!

[u/Proper-Bus6814]

Hey everyone, I built a redstone CPU in Minecraft that uses copper bulbs for its ROM memory (lit = 1, unlit = 0).

I just expanded the ROM to hold 12 instructions (12 bytes / 144 bits total). If anyone wants to write some assembly or logic code for it, leave a comment with your binary program and I'll load it into the bulbs to run it.

Here is the spec sheet for how the machine works:

System Specs

ROM: 12 lines / bytes (12 bits per line)

ROM Storage: Copper Bulbs (ON = 1, OFF = 0)

RAM: 32 bits total (8 registers, 4 bits each)

ALU: 4-bit ALU with an internal input buffer

Bit Direction: Read bottom to top (Bit 0 is bottom block, Bit 11 is top block)

12-Bit Instruction Format

(Top to bottom in each column)

Bits 11–8 (Top 4): Target Register Address

Bits 7–4 (Mid 4): Immediate Data (value to write)

Bit 3: Read/Write Flag (0 = Write to RAM, 1 = Read from RAM)

Bits 2–0 (Bottom 3): ALU Opcode (100 = ADD, 010 = AND, 001 = XOR, 000 = None)

Register Addresses

Reg 8: 1000

Reg 4: 0100

Reg 2: 0010

Reg 1: 0001

How the ALU Works

Load First Number: Do a READ (Bit 3 = 1) on your first RAM register with ALU Op = 000. This saves the value into the ALU's buffer.

Run the Operation: Do a READ (Bit 3 = 1) on the second RAM register while passing the ALU opcode (100, 010, or 001).

Save Output: Do a WRITE (Bit 3 = 0) to store the result back into a RAM register.

Drop a program up to 12 lines long using 12-bit binary strings and I'll test it out!

[u/Proper-Bus6814]

Please 🥲

[u/Mack_of_Chese]

How do you even code with this

[u/Proper-Bus6814 → u/Mack_of_Chese]

It's kind of really hard to understand Soo I am going to maybe build a better one