First Order Of Buisness: ALWAYS mess around with the copy of Sonic CD that is fully installed on your hard drive. You will notice that you cannot switch files directly on the CD (sounds dumb, but it has to be made clear), so use the 'Full Installation' feature in the Sonic CD Setup program.
If you follow this guide promptly, you will be making backup copies of the files so the game can always be brought to its
former state. Remember: things you do here may terminally damage your copy of the game and you will have to reinstall if something
like that occurs. And who wants to reinstall, resulting in their pernament Tima Attack high score loss, eh? ^_^
(Just to mention, Time Attack scores CAN be modified...see the 'Data Handling' section for details)
...blatant cut/paste job following...
Hacking Sonic CD is not like hacking Megadrive/Genesis or GameGear Sonic games (ex. go to address ______, find value X and chage it into ...). Here, you copy the files from one Zone to another and making them replace the ones that were already there.
Take a look at this picture:
It is Palmtree Panic with level structure of Quartz Quadrant. The Rings are still positioned like they were and so is everything else. How did I get it? I renamed the R1/11a/Map11a.bin to Map11a.bak (backup!), copied the R5/51a/Map51a.bin to R1/11a/ and finaly renamed the Map51a.bin to Map11a.bin. There you have it!
If you think the above one is pointless, what will you say about this one:
Pointless??? You're damn right. How did I get this one? I renamed R1/11a/T11a.map to T11a.bak, copied R5/51a/T51a.map to R1/11a/ aaand...(I think you can figure the rest by yourself.)
The funniest thing about this zone are Badniks. Because there is no floor (shock!) they just fall down when you reach them. C'mon, folks, laugh, it's funny!
Hidden Palace? Nope, the Quartz Quadrant's tiles are in Metalic Madness.
There is one more thing to mention. If you try to fool around the level DLLs, the game will show some sort of messed up zone before crashing completley. Weird.
QQZ DLL replaced by MMZ one!
Special stages are hacked differently, yet the process is quite the same. The sole thing you need about it is to mess with the files inside /special directory. For the rest, refer back to the File Listing page...it provides you with anything you need to know.
Here's the result of mixing special stage 7 with 1:
Talk about being sadistic...ahem. Well, this pretty much speaks for itself. Note that although the course changes, Sonic keeps his starting position, and UFOs fly where they normaly do...that's why you can end up in the middle of the ocean at start. Careful!