These are cheat codes that can only be used with game enhancer devices. Listed below are the exceptions covered by the handler, located at ROM address 000004E0: The screenshot above shows an example of the exception handler occurring during gameplay, which is caused by a bug in Labyrinth Zone. Pressing can attempt to advance the game past the exception handler, though in most cases will not work properly, leading to further occurrences of the exception handler or freezing completely. Sonic the Hedgehog uses a basic exception handler in the event a 68000 exception occurs, in which the game stops while unloading all sprites and printing basic information about the exception on the screen. Note that in the case of running REV01 on a Japanese system, these 'pause options' will require an other code which is (it can be used in addition to 'Debug Mode' and 'Level Select' like other versions). Holding during paused gameplay will activate slow-motion, and pressing will display the next frame (it can be pressed more times to show other frames). Alternatively, activating debug mode, pausing during gameplay and pressing will return to the title screen with the feature still activated. It is possible to activate both edit mode and the level select by separating the two codes (before + ) with an button press. The game looks for two (or four) presses during the sequence, but is not concerned about where they are placed - this means, for example, the hint in Sonic Jam, which specifies edit mode as, + is equally valid.

ĭue to a quirk in Sonic 1, other sources will give variations of this code. If running REV01 on a Japanese system, the code is, then +. A Ring sound will play - holding + until the title card appears will activate debug mode.

Sonic 1 title screen sprite