A Chip-8 Emulator developed in Python using PyGame. The purpose of this project was to learn about emulation and gain experience using test driven development.
This emulator includes the ability to reduce flickering by simulating the behaviour of old phosphor displays. Since the pixels of phosphor displays glow for several milliseconds after being turned off, they display a slightly dim sprite rather than a flickering one but increases the appearance of ghosting.
Here is the flickering that would occur without any flicker reduction.
The flickering you see is an accurate emulation of Chip-8. The flickering is due to having a single draw instruction which is used for both drawing and undrawing pixels. For example, a moving paddle is first undrawn and then drawn in a new location. Since the game is essentially a free running loop, drawing can run out of sync with the refresh rate of the display causing the screen to frequently display undrawn sprites.
The project dependencies you'll need to install before being able to play:
- PyGame
- Numpy
Installing NumPy
$ pip install numpy
Installing PyGame. A good guide for your operating system can be found on the PyGame website.
$ python3 -m pip install -U pygame --user
The unit tests for opcodes are located in the test_cpu.py file. Tests use the unittest library and can be run by using:
python3 test_cpu.py -v
Rom files must be placed in the "roms" directory. The emulator can be launched with a specific rom by using the following command in the root directory:
python3 main.py -r <rom_filename>
Include the -f flag to launch the emulator in fullscreen. The repository includes three games, pong.ch8, tetris.ch8 and breakout.ch8.
| 1 | 2 | 3 | 4 |
| Q | W | E | R |
| A | S | D | F |
| Z | X | C | V |
- UP Arrow: Increase Emulation Speed
- DOWN Arrow: Decrease Emulation Speed
- RIGHT Arrow: Increase Pixel Decay Factor
- LEFT Arrow: Decrease Pixel Decay Factor
- Wait for Keypress Instruction
- Keys to control emulation:
- Pause emulator
- Restart emulator
- Joseph Weisbecker, the developer of Chip-8