chip8

A CHIP-8 interpreter/emulator, written twice: once in JavaScript for the browser, and once in Rust on top of SDL2 — and then extended into a machine of its own.

According to Wikipedia,

CHIP-8 is an interpreted programming language, developed by Joseph Weisbecker. It was initially used on the COSMAC VIP and Telmac 1800 8-bit microcomputers in the mid-1970s. CHIP-8 programs are run on a CHIP-8 virtual machine. It was made to allow video games to be more easily programmed for these computers.

js/ — the original

Plain JavaScript, no dependencies and no build step: a <canvas>, the Web Audio API and about four files.

🎮 Test it online now with Pong: https://luisgbm.github.io/chip8/

Remember to use a modern browser and allow audio in the site's settings to be able to listen to all the glorious beeps!

I put some more programs in the js/programs.txt file, you should be able to load them by editing the js/index.html file. See js/README.md.

rust/ — the port

The same interpreter in Rust, running on SDL2 instead of the browser. It bundles every program from js/programs.txt behind an intro screen, can load .ch8 files from disk, and fixes a handful of bugs the JavaScript version carries — see rust/README.md.

cd rust
cargo run --release

It also comes with two ways to write CHIP-8 programs — an assembler, and a small C-like language called C8 that compiles to CHIP-8 — and a game written with both, Leap. If you want to write a program yourself, start at rust/programs/LANGUAGE.md for the language or rust/programs/TUTORIAL.md for the assembler.

chip9/ — the extension

CHIP-8 with the corners knocked off: a fork of the Rust port that adds the four things a CHIP-8 program most often wishes it had, while running every existing CHIP-8 program unchanged.

cd chip9
cargo run --release

• Multiply and divide — MUL and DIV, with the overflow and the remainder in VF.
• A data stack — sixty-four bytes reached with PUSH and POP, separate from the call stack, so a subroutine can finally call itself.
• A font that reaches Z — thirty six glyphs instead of sixteen, so HELLO WORLD needs no sprites of its own.
• C9 — the C-like language grown &&, ||, function arguments, return values and block-scoped local variables.

See chip9/README.md.