Sonic CD 510 Beta

From Sonic Retro

SCHG: Sonic CD 510 Beta
Main Article
File Locations
File Locations
Art Editing
Compressed Art
*.MMD Editing
*.MMD Breakdown
Object Layout
Level Layout
General Tweaking
General Tweaking

This is the Sonic Community Hacking Guide for Sonic the Hedgehog CD (prototype 510). Sonic CD, as with all Sega CD games, uses a filesystem with files for each code event instead of a monolithic rom. Splash screens, menus, and levels all reside in their own .mmd file with optional .bin files for SubCPU execution.

As each MMD runs separately of others (except for those which load to RAM), various pieces of code and data are repeted throughout like MMD files. This makes art editing without a disassembly very long and tedious. However, upon the release of a disassembly of Sonic CD 510, all common art and code will be consolidated so changes are reflected in every MMD including that data.

The level MMDs have the filename format RXYZ__.MMD:

  • X is the zone. R1 is zone 1.
  • Y is the act. R12 is zone 1, act 2.
  • Z is the time period. There are 4 letters that can be put here; A, B, C, or D. A is the present period. B is the past period. C is the bad future period. D is the good future period. So R12D__.MMD would contain act 2 of zone 1, in the good future period.

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Savestate: Sonic 1 | Sonic 2 Beta/Final | Sonic 3

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