mirror of https://github.com/andwati/mos-6502.git synced 2026-10-18 03:02:51 +00:00

Files

T

Implement state saving and loading for CPU and Bus, add tests for various functionalities

- 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.

2026-07-20 13:55:48 +03:00

1.3 KiB

Raw Blame History

Contributor notes

Commands

make              # build bin/mos6502
make test         # core checks
make debug        # strict warning build and checks
make sanitize     # ASan/UBSan build and checks
make snake        # assemble and run the SDL game (requires SDL2 + cc65)

Architecture

CPU6502 contains CPU-visible and interrupt-line state.
Bus6502 owns RAM and Easy6502 MMIO; CPU code only uses bus accessors.
cpu_step executes one instruction or interrupt and returns status/opcode/cycles.
src/opcode.c has a 256-entry descriptor table for all 151 official encodings.
src/state.c owns the portable, versioned state file format.
src/apple1.c maps Apple I keyboard/display PIA registers through bus hooks.
src/frontend.c is an optional SDL2 frontend with a dependency-free stub.
tests/run_tests.c is the in-tree test harness; tests/run_suite.c runs external ROMs.

The target is the NMOS 6502. Preserve decimal-mode flag behavior, zero-page wrapping, the indirect-JMP page-wrap bug, stack push order, and page-cross cycle rules. Do not silently accept undocumented opcodes.

The virtual machine exposes game state at $00FB, high/game score at $00FC/$00FD, random input at $00FE, keyboard input at $00FF, and a 32x32 framebuffer at $0200-$05FF.

1.3 KiB Raw Blame History

Contributor notes

Commands

Architecture

1.3 KiB

Raw Blame History