Nesemuto is an NES emulator written in C# (with an optional dependency on a C++ library for sound emulation).

I'm aiming to strike a balance between performance and cache-friendliness on the one hand and decent code readability and maintainability on the other.

Only the NTSC video system is supported (USA/Japan). PAL games aren't guaranteed to work. I haven't implemented the APU IRQs, so games that rely on the APU for timing purposes won't work properly.

The following mappers have been implemented:

• NROM (000)
• MMC1 (001)
• UxROM (002)
• CNROM (003)
• MMC3 (004)
• AxROM (007)
• GxROM (066)
• Mapper 225

All the official CPU opcodes and some of the unofficial ones are implemented.

Open the solution in Visual Studio or Rider and build the Nesemuto project in Release mode.

The Nes_Snd project, on which Nesemuto depends, is written in C++, so you'll need to have Visual C++ installed on your machine in order to build the solution. Alternatively, you can remove Nes_Snd from the build configuration and turn off the sound emulation by uncommenting
#define NO_APU in Apu.cs. That way, you'll be able to build the emulator without the C++ dependency.

OpenAL is required for the emulator to work: https://www.openal.org/downloads/oalinst.zip

To run a game, simply pass the path to the .nes file as a command line argument:

nesemuto "d:/games/mario.nes"

ZIP files are supported, too:

nesemuto "d:/games/mario.zip"

You can also pass the path to a cheat file as a second argument

nesemuto "d:/games/mario.nes" "d:/games/mario.cht"

The emulator supports raw cheats (with or without a compare value) and Game Genie cheats. The file format looks like this:

// S:addr(hex):value(hex):description
S:0032:09:Player1 Infinite Lives  

// SC:addr(hex):value(hex):compareValue(hex):description
SC:dad3:2c:95:Keep Gun After Dying  

// GG:gameGenieCheat:description
GG:PEETLIAA:Start at area 2      
GG:SLAIUZ:Start with infinite lives

// Lines starting with anything other than 'S:', 'SC:' or 'GG:' are considered comments

Nesemuto uses OpenTK (a set of low-level C# bindings for OpenGL and OpenAL) for rendering and audio output and Shay Green's Nes_Snd_Emu library for the sound chip emulation.

https://opentk.net/ (MIT)

http://blargg.8bitalley.com/libs/audio.html#Nes_Snd_Emu (LGPL)

Nesemuto is free software released under the terms of the MIT license.

NES programming tutorials, hardware reference, and other resources: http://wiki.nesdev.com/w/index.php/NES_reference_guide