Chip-8 Interpreter

A fully functional Chip-8 interpreter written in Rust, demonstrating deep understanding of emulation, low-level systems programming, and graphics rendering.

Technically, it is an interpreter and not an emulator.

Key Achievements

• Accurate CPU Emulation: Implemented all 35 Chip-8 opcodes with precise instruction decoding and execution logic
• Memory Management: Designed and implemented a complete memory model (4KB RAM, stack, and registers) with proper address mapping
• Graphics Rendering: Integrated SDL2 for pixel-perfect display rendering at configurable scales
• Input Handling: Built a complete input system mapping hexadecimal keypad to AZERTY keyboard layouts
• ROM Compatibility: Successfully runs multiple ROM files including IBM logo, test suites, and games (Space Invaders, Pong variants)

Technical Learning Outcomes

Through this project, I learnt about the following subjects:

• Low-level systems programming: Understanding CPU instruction cycles, opcode, memory layout, and register operations
• Rust systems programming: using Rust for systems programming and working with binary operations
• Emulation architecture: Learning how interpreters decode and execute instructions, manage state, and handle timing
• SDL2 integration: Graphics programming and real-time input handling in Rust

Project Demo

IBM Logo ROM

Test ROM - All Digits Passing

Space Invaders Gameplay

Simple Video Game

Requirements

• SDL2: Graphics and input library. Must be installed else program will not compile.
• Rust: 1.56 or later

Usage

Clone the repository and navigate to the project directory:

git clone https://github.com/morukele/Chip-8
cd Chip-8

Running the Interpreter

cargo run -- -r ROM-NAME

This runs the interpreter with default settings and loads the specified CHIP-8 ROM file.

Command-line Options

• -r, --rom: Name of CHIP-8 ROM file (include file extension) [default: 1-chip8-logo]
• -s, --scale: Display scale factor [default: 10]
• -h, --help: Print help information
• -V, --version: Print version information

Example with Custom Settings

cargo run -- -r space_invaders.ch8 -s 15

AZERTY Keyboard Mapping

The Chip-8 was originally designed for AZERTY keyboards. This interpreter maps the 16-key hexadecimal keypad as follows:

Chip-8 Key	AZERTY Key
1	&
2	é
3	"
C	'
4	a
5	z
6	e
D	r
7	q
8	s
9	d
E	f
A	w
0	x
B	c
F	v

Resources

• Write a Chip-8 Emulator
• Chip-8 Technical Reference