Build and run your own version of Epsilon

Install the SDK


We recommend using the Msys2 environment to install most of the required tools. We support Windows 7 and up. Once Msys2 has been installed, launch the Msys2 terminal application, and enter the following commands

pacman -S mingw-w64-x86_64-gcc mingw-w64-x86_64-freetype mingw-w64-x86_64-pkg-config mingw-w64-x86_64-libusb git make python
echo "export PATH=/mingw64/bin:$PATH" >> .bashrc

Last but not least, download and install the latest GCC toolchain from ARM. When prompted for an install location, choose C:\msys64\home\User\gcc-arm\. You’ll then need to add this folder to your $PATH in Msys2 by running this command: echo "export PATH=$PATH:$HOME/gcc-arm/bin" >> .bashrc and restarting Msys2.


We recommend using Homebrew to install all dependencies. Once you have installed Homebrew, install all the dependencies with the following command:

brew install numworks/tap/epsilon-sdk

Debian or Ubuntu

Most of the required tools are available as apt packages:

apt-get install build-essential git imagemagick libx11-dev libxext-dev libfreetype6-dev libpng-dev libjpeg-dev pkg-config

You’ll also need to install the latest version of GCC and make it available in your $PATH:

  1. Download the GCC toolchain distributed by ARM. You should obtain a gcc-arm-none-eabi-x-linux.tar.bz2 file.
  2. Decompress that file with tar xvfj gcc-arm-none-eabi-*-linux.tar.bz2
  3. Add the resulting folder to your $PATH. If you use bash, echo "export PATH=\$PATH:`find $(pwd)/gcc-arm-none-eabi-*-update/bin -type d`" >> ~/.bashrc should do what you need (you’ll need to restart your terminal afterwards).

Alternatively, on Debian 10 and later you can directly install a sufficiently modern cross-toolchain:

apt-get install gcc-arm-none-eabi binutils-arm-none-eabi

Retrieve the source code

The code is hosted on GitHub. You can retrieve it using the follwing command.

git clone

Run Epsilon on your computer

Once the SDK has been installed, just open your terminal (Msys2,, xterm…) and type the following commands:

make PLATFORM=simulator clean
make PLATFORM=simulator

Run Epsilon on your calculator

You can also update your NumWorks calculator easily. Note that you’ll need to press the Reset button and that all data on your calculator will be lost.

make clean
make epsilon_flash

Congratulations, you’re running your very own version of Epsilon!