This is a simple Chip 8 emulator written in C++. CHIP-8 is an interpreted programming language, developed by Joseph Weisbecker. It was initially used on the COSMAC VIP and Telmac 1800 8-bit microcomputers in the mid-1970s. CHIP-8 programs are run on a CHIP-8 virtual machine. It was made to allow video games to be more easily programmed for said computers.
This article on Wikipedia explains the virtual machine(CPU,memory,display and keypad) and the opcodes supported.
Cmake and SDL2 are required for this project. You can install them on Ubuntu using
$ sudo apt-get install cmake libsdl2-dev
For compilation
$ cd cmake-build-debug
$ cmake ..
$ make
The executable file, Chip8_Emulator, will be in the cmake-build-debug folder
You need to provide the path to a ROM file as an argument. 23 ROMS have already been provided in the "roms" directory (downloaded from https://www.zophar.net/pdroms/chip8/chip-8-games-pack.html).
So you can start the PONG game available in the roms directory by
./Chip8_Emulator ../roms/PONG
To run tests
cd cmake-build-debug
make tests
./tests
Catch testing framework is used. More tests need to be added, so PRs are welcome.
There are two modes available - trace mode and single step mode. You can also type -help to check usage
-
Trace mode - Type -t to print the program counter, register values and opcode executed each cycle. It follows this pattern:
pc opcode I sp V0 to VF
-
Single step mode - Type -s flag to execute one instruction at a time waiting for you to press enter after each cycle.
Both modes can be used simultaneously.
The original Chip 8 had a hexadecimal keypad (0 - 9 and A - F). The key mapping here is as follows -
| Chip 8 Key | Keyboard Key |
|---|---|
1 |
1 |
2 |
2 |
3 |
3 |
4 |
Q |
5 |
W |
6 |
E |
7 |
A |
8 |
S |
9 |
D |
0 |
X |
A |
Z |
B |
C |
C |
4 |
D |
R |
E |
F |
F |
V |
This project is licensed under the GPLv3+. The file LICENSE includes the full license text.