SacredSqueegee / Chip-8

Chip-8 interpreter

Chip-8 Interpreter

Current Status:

Working on:

• Chip-8 instruction emulation 0xIXXX
  • I -> Instruction upper nibble
  • XXX -> Rest of instruction
    • 0x0
      • 0x0nnn -> SYS addr -> Not Implementing
      • 0x00E0 -> CLS
      • 0x00EE -> RET
    • 0x1
      • 0x1nnn -> JP addr
    • 0x2
      • 0x2nnn -> CALL addr
    • 0x3
      • 0x3xkk -> SE Vx, byte
    • 0x4
      • 0x4xkk -> SE Vx, Vy
    • 0x5
      • 0x5xy0 -> SE Vx, Vy
    • 0x6
      • 0x6xkk -> LD Vx, byte
    • 0x7
      • 0x7xkk -> ADD Vx, byte
    • 0x8
      • 0x8xy0 -> LD Vx, Vy
      • 0x8xy1 -> OR Vx, Vy
      • 0x8xy2 -> AND Vx, Vy
      • 0x8xy3 -> XOR Vx, Vy
      • 0x8xy4 -> ADD Vx, Vy
      • 0x8xy5 -> SUB Vx, Vy
      • 0x8xy6 -> SHR Vx {, Vy}
      • 0x8xy7 -> SUBN Vx, Vy
      • 0x8xyE -> SHL Vx {, Vy}
    • 0x9
      • 0x9xy0 -> SNE Vx, Vy
    • 0xa
      • 0xAnnn -> LD I, addr
    • 0xb
      • 0xBnnn -> JP V0, addr
    • 0xc
      • 0xCxkk -> RND Vx, byte
    • 0xd
      • 0xDxyn -> DRW Vx, Vy, nibble
    • 0xe
      • 0xEx9E -> SKP Vx
      • 0xExA1 -> SKNP Vx
    • 0xf
      • 0xFx07 -> LD Vx, DT
      • 0xFx0A -> LD Vx, K
      • 0xFx15 -> LD DT, Vx
      • 0xFx18 -> LD ST, Vx
      • 0xFx1E -> ADD I, Vx
      • 0xFx29 -> LD F, Vx
      • 0xFx33 -> LD B, Vx
      • 0xFx55 -> LD [I], Vx
      • 0xFx65 -> LD Vx, [I]
• SDL2 graphics for Chip-8 implementation
• Chip-8 object definitions

Notes about the project so far:

• built on macOS w/ m1 chip
• relies on machines using little endianness
  • So far, only the color configuration is reliant on this.
• relies on sdl2 libraries being in /opt/homebrew/Cellar/sdl2/2.28.3
  • makefile is reliant on this

TODO Items:

• add RAM viewer
• add register viewer
• add instruction stepping capability
  • need to figure out how to handle timers during this?
  • maybe calculate avg. instruction time and advance timer that much???
• add pause feature
• add keyboard re-mapping feature
• add ROM hot reloading feature
• add save states???
• add live display resizing/scaling

Helper Function TODO Items:

• Better logging features
  • more colors
  • nesting support
  • add debug levels so that only levels >= desired debug level will show
  • etc
• Custom SDL2 wrapper specifically for emulators