DDR EXTREME arcade mod that adds "fast" and "slow" timing to gameplay.
8817d0e5 — Charles Magahern 1 year, 4 months ago
Update README with info about 2ndstage
1940875a — Charles Magahern 2 years ago
results: Fix bug where score is misaligned in nonstop results screen
9450271b — Charles Magahern 2 years ago
2ndstage: Fix nonstop/challenge mode


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You can also use your local clone with git send-email.


Gameplay Screenshot

DDR EXTREME CLARITY is a mod for the game Dance Dance Revolution EXTREME that adds "FAST" and "SLOW" judgment indicators to the in-game UI.

Relative timing indicators are complementary to verbal judgment indicators in almost all modern rhythm games. With the addition of "MARVELOUS" timing in DDR EXTREME PRO, this additional UI can assist players in achieving more accurate scoring in a version of the game that has famously had very strict timing.


  • Includes all of the features from DDR EXTREME PRO v2.
  • Adds "FAST" and "SLOW" judgment indicators that appear after every step with a combo.
  • Counts the number of early and late steps during gameplay and adds UI to the results screen to display this for each player.
  • BONUS Enables infinite gameplay with Event Mode by locking each player on the second stage.
  • Can be disabled along with the other "PRO" features in the Test menu.


Building the hack requires access to an existing game image. The hack can be patched onto a vanilla version of DDR EXTREME, or it can be patched on top of DDR EXTREME PRO by SurvivorTEAM. The only thing that is required is the GAME.DAT file from the original game image. This is the only file that will be patched.

The location of the GAME.DAT file within a game's disc image depends on the version. In vanilla DDR EXTREME, this file is in the root directory of the disc's filesystem in a file called GAME.DAT. In DDR EXTREME PRO or any other "superdisc" release, this file is located in a subdirectory called IN, and is named 8G for vanilla DDR EXTREME or 8GP in the case of DDR EXTREME PRO.

NOTE In order to compile the game code, a 32-bit MIPS toolchain is required. For this, the Codescape GNU Toolchain is recommended, which can be downloaded for free here:


First, the game code comprising the feature must be compiled so that it can be injected into the game image.

cd game-code

This will output two files into the game-code/build directory. Both of these will be required for the next step.

Next, run the add_clarity.py script to patch an existing GAME.DAT game image file. The paths to the replacement spritesheet image files, concatenated game code payload, game code manifest, and the GAME.DAT game image file must all be provided.

cd scripts
./add_clarity.py \
    --judgment-spritesheet ../../img/gmob_25_early_late.tim \
    --results-spritesheet ../../img/rslob_25_early_late.tim \
    --payload ../game-code/build/clarity.bin \
    --manifest ../game-code/build/manifest.json \

After this has completed successfully, you now have a patched game image that you can add to a full disc image and burn to run on a System 573. For this, the mkisofs tool is recommended on macOS/Linux, and PowerISO is recommended on Windows.