chip8

Chip8 emulator and debugger

Emulating the Chip8 is probably the "Hello, World!" of emulation software development and, I reckon fair to say; a rite of passage. This is my first stab at an emu and unfortunately, I haven't quite aced the challenge but I did my best to construct an 'academic' implementation of an emulator. This is defintiley not built for performance! But it has pleasant looking code like this:

./system/chip8.js

  cycle()
  {    
    for (let t=0; t<this.cycles; t++)
    {
      if (!this._executing) 
        return;
      
      this.cpu.execute(
        this.cpu.decode(
          this.cpu.fetch()
        )
      )
      
    }
  }

Features:

• Debug: step, dump, stack-trace, disassembler
• Separate UI and emulation threads (WebWorker)
• System 'BIOS'
• Load ROM over http
• Clean abstraction of system componenets (see ./system/ directory)
• Opcode jump table
• Messaging system for decoupled architecture

It was really fun to write this! As mentioned it was more of an academic exercise in implementing the basic structure of a hardware emulator. It was more about the means than the ends. I think the next step up is a Gameboy emulator... but I've had my fill of emu dev :|