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andwati
0dcd2ed687
- Added `state.c` to handle saving and loading the state of the CPU and Bus. - Implemented CRC32 checksum for data integrity verification during state operations. - Enhanced `README.md` in tests/roms to document new test commands for decimal, interrupt, Apple I, and nestest. - Created new test files: `run_apple1.c`, `run_decimal.c`, `run_interrupt.c`, `run_nestest.c`, and `run_vectors.c` to validate the new features. - Updated `run_tests.c` to include tests for state saving/loading and other functionalities. - Introduced `test_vectors.py` to facilitate downloading and running JSON test vectors for opcode verification.
2.1 KiB
2.1 KiB
Project status
Implemented
- 64 KiB bus, reset vectors, deterministic RNG and Easy6502 keyboard/framebuffer MMIO.
- All official NMOS 6502 instructions and opcode encodings.
- Binary and NMOS decimal ADC/SBC, status flags, stack, BRK/RTI, IRQ and NMI.
- All official addressing modes, zero-page wrap, page penalties and indirect-JMP bug.
- Instruction-level cycle accounting and deterministic illegal-opcode errors.
- Stable undocumented NMOS opcode families and multi-byte NOP encodings.
- Safe flat-binary loader, headless runner, optional SDL2 frontend.
- Versioned, endian-defined, CRC32-protected portable save states.
- Extensible bus device hooks and an Apple I terminal/PIA target.
- NES Ricoh 2A03 mode, iNES mappers 0/2/3, PPU register/timing model, controller, scrolling, masks, 8x8/8x16 sprites, sprite status, pulse/triangle/noise audio, SDL frontend, and full 8,991-line nestest match.
- Original ca65 Snake game with pause, persistent high score, and a reproducible
make snaketarget. - Strict debug, sanitizer and dependency-free test targets.
Validation
- 2,360,000 independent SingleStepTests cases cover every implemented official and stable undocumented opcode, final CPU/RAM state, and instruction cycles.
- The interactive debugger supports stepping, continue, breakpoints, register and memory inspection/editing, disassembly, and portable save/load.
The official Klaus Dormann functional suite passes at $3469 after 30,646,176
instructions. Linux CI covers strict, sanitizer, all external CPU/platform suites,
the complete single-step corpus, Snake, and SDL UI builds.
Bruce Clark's exhaustive NMOS decimal suite passes all 131,072 operand/carry combinations, including invalid BCD digits. Klaus Dormann's interrupt suite passes IRQ, NMI, BRK, vector, flag, and concurrent-interrupt checks.
Explicit compatibility boundary
The NES frontend is a useful first-generation NES subsystem, not a claim of full commercial-library compatibility. Mappers other than 0, 2, and 3, DMC audio, cycle-by-cycle PPU bus effects, and mapper IRQs remain outside its stated scope.