CHIP-8 Emulator (C++)

Based on Austin Morlan's CHIP-8 tutorial. Working solution lives in Solution/.

Run a ROM

$env:PATH = "C:\msys64\ucrt64\bin;" + $env:PATH
cd Solution
.\chip8.exe 10 3 Tetris.ch8
.\chip8.exe 10 1 test_opcode.ch8

Args: <Scale> <Delay ms> <ROM>

Sample ROMs

• Games: https://github.com/dmatlack/chip8/tree/master/roms/games
• Tetris: https://github.com/dmatlack/chip8/blob/master/roms/games/Tetris%20%5BFran%20Dachille%2C%201991%5D.ch8
• Opcode test: https://github.com/corax89/chip8-test-rom/blob/master/test_opcode.ch8

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Making your own CHIP-8 games

Totally possible. A .ch8 file is just machine code for the CHIP-8 VM. If your game only uses the opcodes your emulator implements, it will run.

How people make CHIP-8 games

1. Write CHIP-8 assembly — human-readable instructions like LD V0, #05, DRW V1, V2, 5, JP #200.
2. Assemble that into a binary ROM (the .ch8).
3. Load it in an emulator starting at address 0x200.

Some people also use higher-level tools (Octo, CHIP-8 compilers, visual editors) that eventually emit the same kind of bytecode.

Do I need to learn assembly?

Mostly yes — for classic CHIP-8, people usually write CHIP-8 assembly (or something close, like Octo). It’s a small instruction set (~34 ops), so it’s much easier than x86/ARM. You don’t need full “computer architecture school,” just this tiny dialect.

You generally cannot write a normal C++ game and compile it to .ch8. C++ is for the emulator; games are CHIP-8 bytecode.

What you’d need for your own Tetris

• A CHIP-8 assembler (or Octo, popular for CHIP-8 / SuperChip)
• Knowledge of the instruction set your emulator supports (this one follows Austin Morlan / Cowgod-style CHIP-8)
• Game logic from those ops: draw sprites (Dxyn), keypad (Ex9E / Fx0A), timers, RNG (Cxkk), etc.
• Fonts are already in memory at 0x50 if you use Fx29

Compatibility gotchas

Your ROM must match this emulator’s quirks:

• Shift ops (8xy6 / 8xyE) — shifts Vx only (Cowgod style)
• Fx55 / Fx65 — does not increment I
• Display wrapping / collision behavior
• Speed — CHIP-8 has no fixed clock; delay values matter per game

If you stick to plain CHIP-8 (not SuperChip / XO-CHIP extras), this emulator is enough.

Practical starting path

1. Write a tiny program: clear screen, draw a digit, wait for a key.
2. Assemble → .ch8 → run on your emulator.
3. Grow into piece movement, collision, line clear, scoring.

People don’t “export Tetris from Unity into .ch8” — they author CHIP-8 code (or use a CHIP-8-oriented tool) and assemble it. Building your own Tetris for this emulator is a normal, well-trodden project.