The lost Dekoboko track

The lost Dekoboko track

So cool !

Yes, an extra track in Mario Kart Double Dash. Do not expect too much, unfortunately, it seems to be an early version of the Sherbet track in the final version of the game. But it works. Look :)

The magic of kiosk disks

Where does this come from ? From a kiosk demo disk. The kiosk demo discs are the discs containing multiple games, on which you could play many games. Just to tease you. Developers put a large part of the game on these disc and rely on poor “security” mechanisms to prevent the user to access the full game.

In Luigi’s Mansion, you cannot play for more than 15 minutes. But the whole game is on the first demo disc.

With Mario Kart Double Dash, you cannot use up and down on the race selection menu and you can only choose one race. This forces you to play on Luigi’s Circuit. But most of the final version of the tracks are present on the disc.

I guess there are many (many) more differences with the final version of the games and, as prototypes will (hopefully) be released, more and more beta tracks will become available!

The tools you will need.

First, you will need images (isos) of the following gamecube discs :

  • European Demo Disc 10 Demo
  • Mario Kart Double Dash (any version should work)

Then, there are very talented people who built tools to navigate through the files. Here are the ones you will need.

Tool Address Purpose
Dolphin Run a Gamecube image on a computer (testing purpose)
TgcToGcm Enables to turn tgc to gcm files (and play them)
GCREeX ISO decompression and recompression
ArcExtract Decompression tool
ArcPack Compression tool

Your turn !

Step 1 : Extracting the kiosk demo disc

This can be done with GCREeX.

Assuming the iso is called kiosk_demo.iso, and gcreex.exe is in the same folder than the iso, create a text (run.txt) file with the following :

gcreex -x kiosk_demo.iso 

Rename it run.bat and click on it. (or type the command in the command line directly)

Step 2 : Extracting the kiosk version of Mario Kart Double Dash

Now, you have to find the demo version of Mario Kart which should be on the disc. It is the following.


You need to extract it with tgc. Using the command line (or writing a bat file). Assuming tgc2gcm.exe and zz_MarioKartP.tgc are in the same folder, type the follwing command line and expect the following output.

user@:~/ISOs/D88P01/P-D88P/files$ ./tgc2gcm zz_MarioKartP.tgc zz_MarioKartP.gcm
TGCtoGCM by Plootid 2004

Target filesize: 182812672 bytes
Copying GCM, please wait...
Updating GCM...
All Done!

Now you need to extract zz_MarioKartP.gcm with gcreex once again, to access the files of this game.

Step 3 : Getting the files

Now, in the new folder, you need to find Dekoboko.arc.


Now drag and drop this file on ArcExtract.exe. You should have many files appearing. Only keep :

  • dekoboko_course.bco (the collision mask)
  • dekoboko_course.bmd (the graphical model)

(simply copy them)

Step 4 : Extracting Mario Kart Double Dash iso

Same as step one,

gcreex -x mkdd.iso 

Step 5 : Building the beta track



and drop it on ArcExtract. Move the contents in a folder named Snow. Delete the files

  • snow_course.bmd
  • snow_course.bco

And add their dekokoboko equivalents. Rename:

  • dekoboko_course.bco to snow_course.bco
  • dekoboko_course.bmd to snow_course.bmd

Step 6 : Compressing the beta track

Now drag and drop the folder Snow on ArcPack. You should have a new Snow.arc file. Replace the Snow.arc file in the Course folder of mkdd (extracted) iso.

Step 7 : Compressing MKDDs iso


gcreex -c GM4E01

Will generate a new (playable) iso file.

Step 8 : Play

You must be excited. And willing to select the Sherbet Kingdom. If you do so the game will freeze. Instead, just start a track you DID NOT modify. Wait for the race to begin. Now you can press start, select another track and select the Sherbet Kingdom. And it will load. And you will play.

What is next ?

With more tools and more work, you can import pretty much anything. I will write an article soon on how to get this kind of thing working :)


Passionate about Gamecube, coding, statistics, beta games...

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