Recompiled Cosmo's Cosmic Adventure into a native port for modern operating systems

The project provides a native source port of Cosmo's Cosmic Adventure (1992) for macOS, Linux, and Windows. The port utilizes the original game code, including physics, actors, and collision handling, while replacing the hardware-specific layer with an emulated EGA adapter, programmable interval timer, and PC speaker support. The author reports that the port is not an emulator or virtual machine but a native compilation of the game's own code. Development involved using the Cosmore reconstruction of the v1.20 source, which the author states is 96.3% accurate to the original bytes. The project includes automated debugging tools and scripts to verify game behavior, such as timer delivery and keyboard input. While the game runs end-to-end, the author notes that a frame-by-frame comparison against DOSBox remains an unimplemented gap. The project repository is available at https://raw.githubusercontent.com/digows/cosmo/HEAD/README.md. Commit logs indicate that Claude Opus 4.8 participated in the development of various fixes, including resolving save-filename bugs and improving liveness detection for smoke tests.