CrystalNES

A NES Emulator written in Crystal

Current status

• Complete CPU
• Controller
• PPU
  • Basic background rendering
  • Sprite rendering
  • Correct timings
• APU
• Mappers
  • Mapper 0 / NROM
  • Mapper 1 / SxROM
  • Mapper 2 / UxROM
  • Mapper 3 / CNROM
• GUI
  • PPU output
  • CPU Flags and Register values
  • Disassembler
  • Debugger

Usage

raylib needs to be installed on the system.

crystal run main.cr -- path/to/rom.nes

Key mappings

Key	NES Function
A	Select
S	Start
Y/Z	A
X	B
Up	Up
Right	Right
Left	Left
Down	Down
R	Reset
Space	Play/Pause

References

Nesdev Wiki

6502 Reference