# nestur

Nestur is an NES emulator. There are plenty of full-featured emulators out there; this is primarily an educational project but it is usable. There may still be many bugs, but I'm probably not aware of them so please submit issues.
- no use of `unsafe`
- NTSC timing
- supports mappers 0-4 which cover ~85% of [games](http://tuxnes.sourceforge.net/nesmapper.txt)

<img src="pics/smb.png" width=250> <img src="pics/zelda_dungeon.png" width=250> <img src="pics/kirby.png" width=250> <img src="pics/dk.png" width=250> <img src="pics/smb3.png" width=250> <img src="pics/excitebike.png" width=250>

The code aims to follow the explanations from the [NES dev wiki](https://wiki.nesdev.com/w/index.php/NES_reference_guide) where possible, especially in the PPU, and the comments quote from it often. Thanks to everyone who contributes to that wiki/forum, and to Michael Fogleman's [NES](https://github.com/fogleman/nes) and Scott Ferguson's [Fergulator](https://github.com/scottferg/Fergulator) for getting me unstuck at several points.

## Controls
```
 Button  |   Key
___________________
|   A    |    D   |
|   B    |    F   |
| Start  |  Enter |
| Select | R-Shift|
|   Up   |   Up   |
|  Down  |  Down  |
|  Left  |  Left  |
|  Right |  Right |
-------------------

F2: reset console
F5: save game state
F9: load most recent save state
```
If the game is called `mygame.nes`, the save state files will be called `mygame-#.dat`. To load any previous save state, drag and drop a `.dat` file onto the window.

## Use

Double-click or run the executable from a terminal by itself to launch with instructions. Then click Ok and drag a (iNES/`.nes`) ROM file onto the window. Or, drag and drop a ROM file on to the executable to run it directly, or use the path to the ROM file as the first argument to the terminal command.

If the game uses battery-backed RAM (if it can save data when the console is turned off), a save file like `rom_filename.sav` will be created in the same folder as the ROM when the program is exited. When Nestur is run again, it will look for a file matching the ROM name, with a `.sav` extension instead of `.nes`.

## Compilation

1. Install [Rust](https://www.rust-lang.org/tools/install)
2. Have a C compiler
    - Linux: `sudo apt install build-essential`
    - Mac: [XCode](https://apps.apple.com/us/app/xcode/id497799835)
    - Windows: install the [Visual Studio Build Tools](https://visualstudio.microsoft.com/thank-you-downloading-visual-studio/?sku=BuildTools&rel=16) (or [Visual Studio](https://docs.microsoft.com/en-us/cpp/build/vscpp-step-0-installation?view=vs-2019) with the "Desktop development with C++" workload).
3. Install CMake
    - Linux: `sudo apt install cmake`
    - Mac: install [Homebrew](https://brew.sh/) and run `brew install cmake`
    - [Windows](https://cmake.org/download/)
4. `cd nestur/ && cargo build --release` (be sure to build/run with the release flag or it will run very slowly)
5. The `nestur` executable or `nestur.exe` will be in `nestur/target/release`.

## To do

- DMC audio channel

- support other controllers?

## Known problem games

- None currently, please report any issues


Please also check out [Cloaker](https://github.com/spieglt/cloaker) and [Flying Carpet](https://github.com/spieglt/flyingcarpet)!