Install HollyHock3 MOD

HollyHock3 is installed as a mod for your ClassPad. The current installer is made for Windows only.

If you use macOS, follow the Install on macOS guide. If you use Linux, we recommend using a Windows virtual machine. Wine should work too, but if you run into issues, please join our Discord server and tell us what happened.

Disclaimer

Caution

• I am not responsible for any damage you may do to your fx-CP400.
• I am not liable if you brick or otherwise damage your calculator.
• Casio will not fix your calculator if it shows evidence of tampering, like flashing with modified firmware images or using debug menus.
• I will not fix your calculator.
• If you cannot fix your calculator yourself, do not use this toolkit.
• By using these tools, you agree to take full responsibility for any damage that may occur.
• You have been warned.

Install the mod

Go to classpad.dev, then run the installer command from PowerShell:

1. On Windows, press Win + X and choose Windows PowerShell.
2. Copy and paste this command, then press Enter:

irm https://get.classpad.dev/ | iex

3. Follow the installer steps below.

Not on Windows or having issues? Join our Discord server for help.

Installer steps

1. Start the update

Click Update to HollyHock V3.

2. Download the updater

Wait while the installer downloads and prepares the updater. When the Continue button is ready, click it.

3. Plug in the calculator

Plug your calculator into your computer with USB. If the calculator asks you to pick a USB connection mode, do not choose one. Click Cancel on the calculator popup, then click Continue in the installer.

4. Prepare the calculator

Power off the calculator, then hold EXP, ^, and Clear.

While holding these three keys, press the reset button on the back of the calculator for a moment. Keep holding EXP, ^, and Clear until the calculator shows OS ERROR.

If you cannot get the key combo to work, watch this video guide:

When OS ERROR is shown on the calculator, click Launch the Update.

5. Confirm the updater

The official updater window will open. It repeats the same connection and key combo steps. When your calculator shows OS ERROR, click OK.

The update usually takes about 10 minutes. Do not unplug the calculator while it is updating.

6. Finish

When the installer says your calculator is ready, click Finish. You can now start your calculator and check that the HollyHock Launcher is available.

Copy files to your calculator

When the installer is done, plug your calculator back in as USB storage.

First, download the HollyHock launcher file:

1. Open the first run steps.
2. Download run.bin.
3. Keep the file named run.bin.

Then transfer the files to your ClassPad II:

1. Connect your ClassPad II to your computer with USB.
2. Copy run.bin to the root directory of your calculator storage.
3. Copy any .hh3 programs, games, and Python apps you want to run to the root directory too. You can find apps and games in the ClassPadDev store, and Python is available on the Python app page.
4. Safely eject your calculator from your computer.

Launch HollyHock

1. Go to the ClassPad home screen.
2. Open System.
3. Open the top left System menu.
4. Choose Hollyhock Launcher.

Run your app

In the launcher, pick the app you want to run from the list and click Run.

The launcher is a bit slow, so be sure to press for a good second.

Your app should now run.

Troubleshooting

Calculator freezes

If your calculator freezes when launching HollyHock, check that run.bin was copied correctly to the root directory. Try downloading run.bin again and copying it one more time.

Nothing displays in the launcher

If no programs appear in the launcher, check that you copied .hh3 programs or games to the root directory of your calculator. The launcher needs these files to show options.

File transfer issues

If you have trouble transferring files, make sure your calculator is properly connected and recognized by your computer. Try using a different USB cable if needed.