Morse code is a system of representing letters, numbers and punctuation marks by means of a code signal sent intermittently. It was developed by Samuel Morse[1] and Alfred Vail in 1835.
Morse code is a method for transmitting information, using standardized sequences of short and long marks or pulses – commonly known as “dots” and “dashes” – for the letters, numerals and special characters of a message. Originally created for Samuel Morse‘s electric telegraph in the mid-1830s, it was also extensively used for early radio communication beginning in the 1890s. However, with the development of more advanced communications technologies, the widespread use of Morse code is now largely obsolete, apart from emergency use and other specialized purposes, including navigational radio beacons, and by CW (continuous wave) amateur radio operators. Morse code is the only digital modulation mode designed to be easily read by humans without a computer, making it appropriate for sending automated digital data in voice channels, as well as making it ideal for emergency signaling, such as by way of improvised energy sources that can be easily “keyed” such as by supplying and removing electric power (e.g. by switching a breaker on and off).
Morse code can be transmitted in a number of ways: originally as electrical pulses along a telegraph wire, but also as an audio tone, as a radio signal with short and long pulses or tones, or as a mechanical or visual signal (e.g. a flashing light) using devices like an Aldis lamp or a heliograph. Because Morse code is transmitted using just two states – on and off – it was an early form of a digital code. International Morse code is composed of six elements:
1. short mark, dot or “dit” (·)
2. longer mark, dash or “dah” (–)
3. intra-character gap (between the dots and dashes within a character)
4. short gap (between letters)
5. medium gap (between words)
6. long gap (between sentences)
However, the variable length of the Morse characters made it hard to adapt to automated communication, so it was largely replaced by more regular formats.
What is called Morse code today actually differs somewhat from what was originally developed by Alfred Vail in collaboration with Morse. In 1848 a refinement of the code sequences, including changes to eleven of the letters, was developed in Germany and eventually adopted as the worldwide standard as “International Morse”.