CHIP-8 Emulator

A CHIP-8 emulator written in Rust.

Features

• Full CHIP-8 instruction set
• 64×32 display rendered with pixels + winit
• 440 Hz beep audio via rodio
• 60 Hz frame loop with 10 CPU cycles per frame
• Standard QWERTY → CHIP-8 hex keypad mapping

Requirements

• Rust (stable)

Build & Run

cargo build --release
cargo run --release -- path/to/rom.ch8

Pass the path to any .ch8 ROM file as the first argument.

Keyboard Layout

The original CHIP-8 used a 16-key hex keypad. This emulator maps it to QWERTY as follows:

QWERTY	CHIP-8
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 0 B F

Architecture

File	Purpose
src/chip8.rs	Core emulator — CPU, memory, display, timers
src/utils.rs	Opcode nibble extraction helpers
src/main.rs	Window setup, event loop, audio, key mapping

Memory layout:

• 0x000–0x04F: Reserved
• 0x050–0x09F: Built-in fontset (digits 0–F)
• 0x200–0xFFF: ROM + program memory

Implementation notes:

• op_store_regs / op_load_regs do not increment I (modern CHIP-8 behaviour)
• RNG uses a simple LCG — no external rand crate
• Timers decrement once per frame (tied to the 60 Hz loop, not a separate 60 Hz tick)

ROMs

This repository does not include any ROMs. The included Breakout.ch8 ROM used during development is not mine — it was sourced from the internet. Many public-domain CHIP-8 ROMs are available at places like chip8Archive or Zophar's Domain.

You can load any compatible .ch8 file by passing its path on the command line.

License

MIT