About
Rights and trademarks to Cosmo's Cosmic Adventure and its assets are credited, per Cosmore's own license notes, to Apogee Software. Cosmore is a reconstruction of the source code for Cosmo's Cosmic Adventure version 1.20, built using the original 1988-era Borland Turbo C 2.0 and Turbo Assembler 1.0 toolchain to reproduce the original DOS binary as closely as possible, matching its segment layout, function order, and instruction sequence. Its author measures 96.30% byte-for-byte accuracy against the original executable (excluding EXE headers and relocation tables), with the remaining gap limited to the arrangement of uninitialized BSS memory. It requires a DOS environment (such as DOSBox) to build and run, and needs the player's own copy of the original game's data files. A companion project, Cosmodoc, documents the game's internals in further detail.
How it differs from the original
Despite the near-byte-identical reconstruction, Cosmore's compiled binaries differ from the originals in the exact arrangement of the EXE relocation table and in the ordering of uninitialized BSS variables, which changes some instruction displacement bytes and could cause different behavior for any out-of-bounds-memory bugs; as a result, the compiled file hashes don't match the originals. The project includes no original game data — players must supply their own copy of the episode(s) they want, with only Episode 1 freely available as shareware.
Getting started
Building requires a DOS environment (DOSBox is suggested) with Borland Turbo C 2.0 and Turbo Assembler 1.0 installed, then running the build command for the desired episode (1, 2, or 3), or the included release script to build and compress all three at once. Playing requires the original game's data files for that episode, of which only Episode 1 is freely available as shareware.
Additional notes
- License
- Cosmore's own code is MIT-licensed, except for a couple of bundled third-party files (Borland's C0.ASM startup code and the LZEXE compression tool).