nesv is a toy RISC-V emulator that runs entirely on the Nintendo Entertainment System (NES), written in C (compiled with cc65), demonstrates that a modern 32-bit ISA can be emulated on 8-bit retro hardware.

The fun idea of running a modern 32-bit ISA on an 8-bit 80s console.

Playing with RISC-V’s 32-bit address space while living inside the NES’s 2 KB of RAM is an absurd but educational exercise.

It’s a mash-up of computer history: late-70s 6502 meets modern 2010s RISC-V.

It’s completely impractical, but that’s exactly what makes it fun: seeing RISC-V assembly actually run on NES hardware.

• Supports core RV32I instructions: arithmetic, logical, loads/stores, and branches.

• Simple bus abstraction for memory access (NES RAM mapped as RISC-V memory).

• Debug text renderer: NES screen shows registers, PC, and instructions.

• Runs test RISC-V binaries embedded in ROM.

To build and run, you’ll need the following tools:

• cc65 cross development toolchain
• NES emulator (e.g., FCEUX)

This project is licensed under the BSD 3-Clause License. See the LICENSE file for details.