eNESulator

NES emulator written in C++

Introduction

This is my version of an emulator for the Nintendo Entertainment System. I've used this as a (rather ambitious) way to learn C++.

It is still WIP, but has been tested and confirmed running with the following roms:

• '1942.
• Castlevania.
• Donkey Kong.
• Excitebike.
• Ice Climber.
• nestest
• Super Mario Bros.

Features:

• Official NES opcodes.
• 1-player controls.
• Mappers: iNES 000 & 002.
• Horizontal and vertical scrolling.
• 8x16 sprites.
• Basic APU implementation (DMC is not passing the various test ROMs).

Future improvements:

• Fix DMC channel in the APU.
• Additional mappers.
• Battery-backed RAM.
• Save states.
• 2-player controls.
• Work through the various test roms and fix issues as required.

Prerequisites:

SDL2 is used for handling the GUI and controller inputs.

I have verified this is working with C++17 and C++20 on Fedora 41. Note that C++20 is only required if you want to use std::format to display hex numbers with the leading 0x on the GUI.

Compiling, building, and running the emulator

You can use GNU make from the src directorym with various options such as make clean or make clean_objects.

References:

There were many references that helped me through this project. Some notable ones are:

• OneLoneCoder's series on writing a NES emulator: https://github.com/OneLoneCoder/olcNES
• David Poo's series on writing a 6502 CPU emulator: https://www.youtube.com/playlist?list=PLLwK93hM93Z13TRzPx9JqTIn33feefl37
• The entire Nesdev Wiki: https://www.nesdev.org/wiki/Nesdev_Wiki
• Famicom Party: https://famicom.party/
• Emulation Online: https://www.emulationonline.com/systems/nes/
• emudev: https://emudev.de/nes-emulator/overview/
• nes-test-roms: https://github.com/christopherpow/nes-test-roms

Disclaimer

This program is not endorsed by Nintendo.