Yarchi

Yet Another Rust CHIP-8 Interpreter!

Yarchi is a simple yet functional CHIP-8 interpreter (emulator).

Features

• Runs CHIP-8 programs and games (obviously!)
• Adjustable screen size
• Adjustable emulation speed
• Adjustable fore- and background color
• Possibility to run in CHIP-48 mode (required for some games to function properly)
• Debug mode

Prerequisites

The interpreter depends on SDL2 library in order to handle video, audio and inputs. It must be therefore installed on your system.

On GNU/Linux operating systems this can be as simple as installing (example from Ubuntu 20.04):

apt install libsdl2-2.0-0

or on a MacOS (with brew):

brew install sdl2

For more information please see https://formulae.brew.sh/formula/sdl2.

Running the interpreter

Simply run from your command line, while specifying the ROM path and passing arguments / flags.

For example, to run a program in debug mode with large screen:

./yarchi -d --screen-size large path/to/your/program.rom

Building the interpreter

Yarchi depends only on a handful of dependencies and can be built very simply with the standard Rust toolchain by running from within the root directory:

cargo build

Controls

Controls use the 'typical' mapping which is the following:

(left: mapped on keyboard, right: original controls)

1	2	3	4		1	2	3	C
Q	W	E	R		4	5	6	D
A	S	D	F		7	8	9	E
Z	X	C	V		A	B	C	D

*the mapping is independent of your keyboard layout (i.e. bottom left key, whether Z or Y, is always A)

Debug Mode

The interpreter also contains a debug mode, which can be 'activated' by passing -d or --debug. This mode makes it possible to inspect CHIP-8's state (program counter value, register values etc.), to pause / resume emulation and to execute emulation cycles one by one (when paused).

The described actions are available upon pressing:

• P - prints current state of CHIP-8
• End - pause/resume emulation
• PgDown - executes next cycle (4 instructions; possible only if emulation is paused)

Contributions and collaboration

Something's not working right? Do you want to add a feature to the interpreter? Are you building one yourself and have questions?

Pull requests as well as opening an issue is more than welcome!