Yes, but the old ways were that the terminal interface itself was in charge of translating this keycode to a signal, based on the line discipline of the termina

Yes, but the old ways were that the terminal interface itself was in charge of translating this keycode to a signal, based on the line discipline of the terminal. It was a consistent behavior across many apps unless they took effort to modify the current terminal line discipline, i.e. put the terminal into a raw mode. And then many apps tried to do something appropriately signal-like when they decided to handle these input characters without signals.