🥔 Potatis

• /mos6502 - Generic CPU emulator. Passes all tests, including illegal ops. (No BCD mode).
• /nes - A very incomplete NES emulator.
• /nes-sdl - Native target using SDL.
• /nes-wasm - Browser target using WASM.

/mos6502

let load_base = 0x2000;
let mem = Memory::load(&program[..], load_base);
let cpu = Cpu::new(mem);
let mut machine = Mos6502::new(cpu);

loop {
  machine.tick()
  println!("{}", machine); // Will print nestest-like output
}

Debugging

let mut debugger = machine.debugger();
debugger.verbose(true); // Trace, dumps disassembled instructions to stdout
debugger.add_breakpoint(Breakpoint::Address(0x0666));
debugger.add_breakpoint(Breakpoint::Opcode("RTI"));
debugger.watch_memory_range(0x6004..=0x6104, |mem| {
  // Invoked when memory in range changes
});

/nes ⚠️ WIP ⚠️

Supported mappers:

• NROM (mapper 0)
• CNROM (mapper 3)
• MMC3 (mapper 4)

impl nes::HostSystem for MyHost {
  fn render(&mut self, frame: &RenderFrame) {
    // frame.pixels() == 256 * 240 * 4 RGBA array
  }

  fn poll_events(&mut self, joypad: &mut Joypad) {
    // pump events and forward to joypad
  }
}


let cart = Cartridge::blow_dust("path/to/rom.nes")?;
let mut nes = Nes::insert(cart, MyHost::new());

loop {
  nes.tick();
  println!("{:?}", nes); // Complete nestest formatted output
}

/nes-sdl

cargo run --release path/to/rom.nes

cargo run -- --help for options

/nes-wasm

1. cd nes-wasm
2. wasm-pack build --release --target web
3. npm install
4. npm run dev

Test

Run all unit and integration tests (for all crates):

cargo test

TODO

• More mappers
• APU

Thanks

• https://www.masswerk.at/6502/6502_instruction_set.html
• https://github.com/amb5l/6502_65C02_functional_tests
• http://www.baltissen.org/newhtm/ttl6502.htm (TTL6502.bin test)
• https://www.nesdev.com/neshdr20.txt
• https://github.com/christopherpow/nes-test-roms
• http://nesdev.org/loopyppu.zip
• https://www.youtube.com/watch?v=-THeUXqR3zY
• https://archive.nes.science/nesdev-forums/f2/t664.xhtml