Samuel Morse was the Human inventor of Morse code, an ancient form of Earth communication that uses dashes and dots, short and long tones or delays in knocks. Morse code was still recognized by Starfleet officers in the 23rd and 24th centuries. (TOS novel: The Fearful Summons, TOS movie: Star Trek V: The Final Frontier, VOY episode: "The 37's")
Samuel Morse article at Wikipedia, the free encyclopedia.