Choose tools that target CD hardware
A Mega Drive cartridge tutorial is helpful background, but does not automatically initialize the CD subsystem or build a bootable disc. Megadev is an original development framework for Mega Drive and Mega-CD using C and 68000 assembly. Its author points to the project manual for installation and expects some programming and embedded-system experience. Blast SDK is another original Sega CD-oriented project. Evaluate its build instructions and examples on your actual operating system before committing to an engine.
The scanned Sega development manuals cover the two CPU environments, disc layout, BIOS calls and backup RAM. Use them to resolve hardware behavior. Keep a note of the manual revision and repository commit used for a project. A compiler upgrade can change output even when the source is unchanged; pinning the tools makes a later regression understandable.
Build the smallest working project first
- Install only the dependencies required by the selected framework, using its current documented commands.
- Build an untouched example and retain the complete build log.
- Confirm that the output includes the expected disc layout and all tracks, rather than only a raw executable.
- Run the example in a supported emulator with a legally supplied matching BIOS.
- Test on a known working physical system or a manufacturer-documented compatible CD core.
Make the first change something visible and small, such as a title string or an input response. If the original sample fails, solve the environment or media issue before adding your game. Create a test table with emulator version, base-console region, CD BIOS, loading method and result. “It works on my emulator” is useful evidence for that configuration, not a universal compatibility claim.
Plan loading and persistence deliberately
Identify which processor owns each task and how shared resources are coordinated in the framework. Begin with one small asset set before experimenting with streaming. A stalled load should be reproducible with a particular file and transition. Log or display a progress marker in development builds so booting, file reading and drawing failures can be distinguished. For audio, test one intentional CD track and one effect, then verify the final disc image still contains both.
Keep saves optional in early examples. Add a disposable save slot, shut down normally and verify a subsequent load before storing valuable user progress. Test insufficient free space and a missing backup cartridge as ordinary conditions. Consult the BIOS reference rather than inventing a storage format that another game or utility could mistake for valid backup RAM.
Release something another person can verify
Distribute source or a clear build description, required hardware, expected BIOS region, full track layout, file checksums and a short test procedure. Include the license for original code and assets; obtain permission for reused content. Publish a ready-to-run image only when every included asset can be redistributed. Separate physical-drive results from MegaSD or Mega EverDrive Pro results, because their hardware combinations and timing behavior differ. Keep reported failures alongside the release notes so future developers can investigate rather than silently repeating the same setup.