Enjoy using your favorite classic HP calculator on your desktop, with this simulator:

• Classic series: HP 35, HP 80, HP 45, HP 70
• Woodstock series: HP 21, HP 22, HP 25, HP 25c, HP 27, HP 29c
• Spice series: HP 31e, HP 32e, HP 33e, HP 33c, HP 34c, HP 37e, HP 38c, HP 38e
• Voyager series: HP 10c, HP 11c, HP 12c, HP 15c, HP 16c
• Others: HP 67

Right-click on desktop icon and select 'Set default calculator' to set default model, or choose one of the available simulators from list. Alternatively you can access the configuration dialog from a terminal using flatpak run io.github.mike632t.x11-calc --setup

Note: For best results the following fonts should be installed: xfonts-base (Debian/Ubuntu), xorg-x11-fonts-base or xorg-x11-fonts-misc (Fedora), font-misc-misc (Gentoo).