unrenormalizable/rustella

Atari 2600 Emulator written in Rust.

rustella - Atari 2600 Emulator written in Rust

Built with rust-analyzer.vs (free Visual Studio 2022 Extension)

What?

Why?

Why not?

Development Principles

• Clean room implementation
  • Not allowed: Referring to any existing emulator code or design.
  • Allowed: Datasheets / tutorials / discussions on the web that is not emulator code / design.
• Emulation in no_std + safe Rust, WebAsm hostable.
• Test driven development.
• v1: Just sufficient to play the very basic games.
• v1: Web front-end with hardware debugger.

Progress

• CPU
  • Clock cycle accurate NMOS 6502 / 6507 emulation
  • Hardware debugger
  • Passing HCM & Klaus test suites
  • Undocumented opcodes
• RIOT
  • RAM + memory shadowing / mapping
  • Timer
  • Joysticks
  • Sound
  • Bank switching
• TIA
  • Background + playfield
  • Player sprites
  • Missile sprites
  • Ball sprite
• TV
  • NTSC Webasm-in-React on browser
  • PAL/SECAM
• Run early Atari games
• Run advanced Atari games

Specs

• CPU: 6507, 1.19 MHz
• Memory: RAM - 128 Bytes in VLSI, ROM - 4K max
• Graphics: A custom chip named Stella and a graphics clock that run at 1.19 MHz
• Storage Method: Carts
• Input: 2 Joystick ports

References

• 2600 Tech specs
• Reference hardware - 1
• Reference hardware - 2
• CPU
  • 6502 Instruction set
  • 6502 Family CPU Reference
  • Ultimate Commodore64 Reference Guide
  • 6502 primer
  • The 6502 Microprocessor Resource
  • 6502 datasheet
  • The 6502/65C02/65C816 Instruction Set Decoded
  • Tests
    • 6502 CPU tests
    • 6502_65C02_functional_tests
    • Tom Harte style JSON
• Memory
  • 2600 Memory layout
  • 6502 Memory map requirements
• TIA
  • The TIA and the 6502
  • Atari 2600 TIA Hardware Notes
• References
  • ROMS: Open AI Gym: <user>\.conda\envs\rlenvs\Lib\site-packages\AutoROM\roms