CHIP-8 Emulator

A CHIP-8 emulator written in C++ using SDL3 for rendering and input. CHIP-8 is an interpreted programming language developed in the mid-1970s, originally used on 8-bit microcomputers. This emulator lets you run classic CHIP-8 ROMs — games like Pong, Tetris, Space Invaders, and more.

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Features

• Full CHIP-8 instruction set (35 opcodes)
• 64x32 pixel display scaled to 640x320 via SDL3
• 60Hz emulation loop (~11 instructions per frame)
• Delay and sound timers
• Keyboard input mapped to the original CHIP-8 hex keypad

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Requirements

• C++20 or later
• CMake 3.20+
• Git (used by CMake to fetch SDL3 automatically)
• A C++ compiler: GCC, Clang, or MSVC

No need to install SDL3 manually. CMake fetches and builds it automatically via FetchContent.

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Installation

1. Clone the repository

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

2. Build the project

mkdir build && cd build
cmake ..
cmake --build .

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Usage

./Chip-8-cpp <path-to-ROM>

Example:

./Chip-8-cpp games/pong.ch8

On Windows, open the project via the solution in Visual Studio after running cmake .. and build from there.

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Key Mapping

The original CHIP-8 used a 16-key hex keypad (0–F). It is mapped to your keyboard as follows:

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

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Project Structure

Chip-8-cpp/
├── src/
│   ├── core/
│   │   ├── Chip8.h        # Emulator class definition
│   │   └── Chip8.cpp      # Opcode implementation, memory, timers
│   └── main.cpp           # SDL3 window, render loop, input handling
├── img/
│   └── Pong.png
├── CMakeLists.txt
└── README.md

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How It Works

The emulator follows the standard CHIP-8 architecture:

• Memory: 4KB (0x000–0xFFF). The ROM is loaded starting at 0x200. Bytes 0x000–0x1FF store the built-in font sprites.
• Registers: 16 general-purpose 8-bit registers (V0–VF). VF is used as a flag register by several instructions.
• Display: 64x32 monochrome pixels stored in a flat array (gfx). Sprites are drawn with XOR logic — overlapping pixels set VF to 1 (collision detection).
• Timers: Two 8-bit timers (delay and sound) that count down at 60Hz. When the sound timer hits 0, a beep is triggered.
• Opcodes: Each instruction is 2 bytes. The emulator fetches, decodes, and executes ~11 instructions per frame at 60Hz.

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I've been quite happy with how it turned out, even if it's not the best implementation 😭😭😭, i will probably next do the nes one.