Sunrest

Sunrest is a NES emulator written with the purpose of learning Rust and understanding how an emulator works.

Usage

Usage: sunrest [OPTIONS] <ROM>

Arguments:
  <ROM>  Path to a ROM file

Options:
      --volume <num>   Volume of the audio
      --speed <num>    Speed of the emulation
      --replay <FILE>  Path to the replay file
      --record <FILE>  Path to save the replay file
  -h, --help           Print help

The emulation is not accurate, games might display various glitches

Buttons

Keyboard Key	Nes Pad
A	Left
S	Down
D	Right
W	Up
J	A
K	B
Enter	start
Backspace	select
[	save state
]	load state

Settings

Beside the command line arguments, the emulator can be configured using environment variables.
The following environment variables are supported:

env	description
SUNREST_SPEED	emulator speed ratio (default: 1.0)
SUNREST_VOLUME	audio volume (default: 1.0)

Supported Roms

• Only the iNes v1 format (.nes) is supported for ROMs.

The implemented mappers and the list supported ROMs for each mapper are:

mapper	rom list
000	https://nescartdb.com/search/advanced?ines=0
001	https://nescartdb.com/search/advanced?ines=1
002	https://nescartdb.com/search/advanced?ines=2
003	https://nescartdb.com/search/advanced?ines=3
004	https://nescartdb.com/search/advanced?ines=4

Building

To ensure optimal performance, make sure to build the emulator with the --release flag enabled. Without this flag, the emulator may run too slowly.

cargo build --release

Tests

There are some optional tests (marked as ignore) relying on test ROMs available at nes-test-roms.
To run these tests, follow the steps below:

1. Clone the nes-test-roms repository to your local machine.
2. Set the NES_TEST_ROMS_PATH environment variable to the path where you cloned the nes-test-roms repository.
3. Run the tests, ensuring that you enable the ignored tests.

git clone https://github.com/christopherpow/nes-test-roms $HOME/nes-test-roms
NES_TEST_ROMS_PATH=/$HOME/nes-test-roms cargo test -- --include-ignored

Acknowledgments

While creating this emulator, I heavily consulted the following sources:

• https://www.nesdev.org/ - The bible
• https://www.masswerk.at/6502/6502_instruction_set.html - 6502 instruction set documentation
• javidx9's NES Emulator From Scratch Youtube series
• https://github.com/ulfalizer/nesalizer - A NES emulator written in C++
• https://github.com/fogleman/nes - A NES emulator written in Go