"Morse code" is used to express letters and numbers by combining codes of different lengths, such as "Ton Ton Ton, Toe". Although it is a Morse code that uses only two codes, it is hard to memorize ...
The Titanic famously (or infamously) used Morse code to call out in distress at the end of its final voyage. Ships at sea and the land-based stations that supported them used Morse code for decades, ...