Yes, the signals are for tough dragons :)
The Fullscreen button I removed as on Itch it didn't really work - it could occupy the whole screen, but the game remaining 640x480, which was kind of pointless (or did you see it working in some environment?). Some time in the future I will try to work on a better Uzebox web emulator, EEPROM state saves would also be really nice.
Fullscreen: yes at first the fullscreen button (with the ICON only) wasn't of much use since the game canvas was still small in an empty page.
But(!) I noticed there was a kind-of hidden actual white button with "Fullscreen" on it that appeared for a second at launch and then it was pushed down out of the iframe: but if I gave the focus to the description and pressed shift+TAB (or even simpler, drag the fullscreen icon and then press TAB) I had the focus on the white "Fullscreen" button that worked perfectly for me, Chrome on Win10.
