C++ Chip-8 Emulator

A feature-complete Chip-8 interpreter written in C++11, using SDL2 for rendering and input handling. This emulator runs standard Chip-8 ROMs (games/programs).

Features

• Full Opcode Support: Implements the standard Chip-8 instruction set.
• Scalable Graphics: Resizable window with configurable scale factor.
• Configurable Speed: Adjustable CPU cycle delay to control emulation speed.
• Cross-Platform: Runs on Linux, Windows, and macOS (requires SDL2).
• Keyboard Input: Maps modern keyboards to the hex keypad.

Prerequisites

To build this project, you need:

• C++ Compiler (GCC, Clang, or MSVC) supporting C++11.
• CMake (Version 3.14 or higher).
• SDL2 Library (Development headers).

Installing Dependencies (Fedora Linux)

sudo dnf install gcc-c++ cmake make SDL2-devel

Installing Dependencies (Ubuntu/Debian)

sudo apt-get install build-essential cmake libsdl2-dev

Build Instructions

1. Clone or download this repository.

2. Open a terminal in the project folder.

3. Run the following commands:

# Create a build directory
mkdir build
cd build

# Generate the Makefile
cmake ..

# Compile the executable
make

Usage

Run the emulator from the command line. You must provide three arguments:

./chip8 <Scale> <Delay> <ROM_Path>

• Scale: Integer. Multiplies the original 64x32 resolution. (Recommended: 10 to 20).

• Delay: Integer. Milliseconds to wait between CPU cycles. Lower is faster. (Recommended: 1 to 4).

• ROM_Path: Path to a valid .ch8 or .rom file.

Example

To play Pong with 15x scale and 3ms delay:

./chip8 15 3 ../roms/PONG

Controls

The original Chip-8 used a 16-key hexadecimal keypad (0-F). This emulator maps them to the left side of your QWERTY keyboard:

Chip-8 Key	Keyboard Key	Action (Standard Games)
1	1
2	2
3	3
C	4	Player 2 Up (Pong)
4	Q	Player 1 Up (Pong)
5	W
6	E
D	R	Player 2 Down (Pong)
7	A	Player 1 Down (Pong)
8	S
9	D
E	F
A	Z
0	X
B	C
F	V

• ESC: Exit the emulator.

Project Structure

• Source/Chip8.cpp/hpp: Core CPU logic, memory, and opcode implementation.

• Source/Platform.cpp/hpp: Handles graphics (SDL2) and input events.

• Source/Main.cpp: Entry point, main loop, and argument parsing.

• CMakeLists.txt: Build configuration.

Troubleshooting

• "Segmentation Fault": Usually happens if the ROM path is incorrect. Double-check that the file exists and the path is right relative to where you are running the terminal command.

• Game is too fast/slow: Adjust the second argument (Delay). Increase the number to slow it down, decrease it to speed it up.

A big thanks to Austin Morlan and his blog