Begin by upgrading your system and installing the necessary components.

sudo dnf upgrade
sudo dnf install make gcc SDL3 SDL3-devel fossil

Run fossil to download the repositories and disk images. This may take quite some time, especially when downloading the disk images. Being large individual files, they can't download in parallel and the server is rate-limited. Please be respectful with your downloads.

fossil open https://tumbleweed.nu/r/l --workdir l --repodir .
cd ./l

Give executable permissions, and build the system with the make script.

chmod +x ./m
./m

Copy the System 303 config file and open it up with your editor of choice.

cd ./usim
cp ./usim-303-0.ini ./usim.ini
vi ./usim.ini

Under the keyboard options, comment out the line:

[kbd]
#F7 = integral

Finally, you should be able to run the simulator.

./usim