SONIC & KNUCKLES CART-SWITCHING

Huh? What's this? Well, you can get some interesting effects by switching the cart that's locked-on to S&K without turning off the power!

Please note: I accept NO responsibility for damage to your Genesis or game cartridges as a result of doing this.

The first interesting thing is when you remove the Sonic 2 cart while playing Knuckles in Sonic 2.
1. Lock-on Sonic 2, and start the game as normal
2. Pause the game when the level title disappears.
3. WITHOUT turning off the power, carefully remove the Sonic 2 cart that's locked-on.
4. If you want, carefully insert another, non-Sonic game.
Now unpause. Knuckles will go crazy, bumping into things that aren't there, the music will be wierd, and eventually Knuckles may fall through the floor and die. More likely however is that the game will encounter an error, causing it to reset to either S&K alone or the No Way screen.

So far I haven't been able to get this working on emulators via ROM-switching with savestates (see below), the game just resets itself as soon as the save is loaded. Someday I might put up some screenshots or videos of this effect happening on a real Genesis.

The next item is far more useful. You know the special stages you can access when you plug a non-Sonic game into S&K? Have you noticed how some games (e.g. Sonic 3D Blast) just cause the game to start as S&K alone? If you want to play their special stages, this trick is for you!

• Firstly, start up Sonic & Knuckles with a non-Sonic game that DOES give a special stage. I use Mortal Kombat, but other games should work too.
• Then, start the special stage, and pause as soon as the 'Get Blue Spheres' message disappears.
  Now comes the tricky part...
• WITHOUT turning off the power, carefully remove the first non-Sonic game and lock-on the game that doesn't give a special stage.
  If you don't do it gently enough the game will freeze and you'll have to switch off and start again.
• After doing this, unpause the special stage and hit a red sphere

You'll return to the GET BLUE SPHERES screen, but the number at the top will have changed. You can now press Start to play the special stage generated by the game that 'doesnt' work! Someday I may put up illustrative screenshots of how to do this.

Finally, we have probably the most useful trick of all. If you lock-on a non-Sonic game to S&K, and beat the special stage with a Perfect, (getting all the rings), you then get a code which allows you to play that level with Sonic 1 locked-on (Special Stage Challenge). How about an easy way of getting the code?

• Firstly, start up Sonic & Knuckles with the non-Sonic game that gives a special stage.
• Then, start the special stage, and pause as soon as the 'Get Blue Spheres' message disappears.
  Now comes the tricky part...
• WITHOUT turning off the power, carefully remove the first non-Sonic game and lock-on Sonic 1
  If you don't do it gently enough the game will freeze and you'll have to switch off and start again.
• After doing this, unpause the special stage and hit a red sphere...

And there you have it! The code for that special stage will appear on the GET BLUE SPHERES screen, even though you lost the stage!

You can also do this trick on emulators, by doing the following steps:

1. Create a hybrid ROM of S&K and the game you want the special stage of, using the DOS copy /b command, like so:
   
2. Load up the emulator with your new ROM (TEST.BIN in the above example), and press A+B+C to get the special stage mode
   
3. Start the special stage, and pause as soon as the Get Blue Spheres message disappears. Then, make a savestate
   
   Now comes the tricky part...
4. Exit to DOS, and copy or rename your savestate to what your Sonic 1 & Knuckles combination ROM is called, like so:
   
5. Load up the emulator with Sonic 1 & Knuckles, and load the savestate you copied.
6. Unpause, crash into a red sphere, and...
   
   There you have it! The code for that special stage, without having to bother getting a Perfect!