Morse code
Morse code was an antiquated means of audio or visual non-verbal communication via technology developed on Earth, during the 19th and 20th centuries, such as telegraphs. A message in Morse code was transmitted from a transmitting set and was received by a receiving set. (; ) Some people were still familiar enough with it into the 22nd, 23rd and 24th centuries to utilize or recognize it. (; ; ; ) 

In 2024, Raffaela Musiker and Seven of Nine wondered if a series of activations of Cristóbal Rios' combadge could be Morse code. It was actually a young boy, Ricardo, playing with the badge at Clinica Las Mariposas. ()

In 2152, Hoshi Sato attempted to use Morse code to communicate with Jonathan Archer while she experienced a hallucination during her first experience aboard a transporter. ()

In 2257, Sylvia Tilly suggested Morse code as an alternative way to communicate with the  when its communications systems were too compromised for voice transmission. ()

In 2267, "general call"  Morse code was transmitted automatically by the  and the code was received by the . Nyota Uhura received and identified it. ()

In 2287, Montgomery Scott tapped out "stand back" in Morse code on the back of the 's brig moments before blasting a hole through the wall, thus freeing Leonard McCoy, Spock and James T. Kirk. ()

Morse code was mentioend in a detective novel Data was reading in early 2364 to become more prepared for a Dixon Hill adventure. He was employed by Silent Forrester.()

In 2371, the  discovered an Morse code signal for SOS (··· ­­­­­­­­−−− ···, three dots, three dashes, three dots) emanating from a planet in the Delta Quadrant. ()

In 2377 during the third segment of the Antarian Trans-stellar Rally Harry Kim had to alert B'Elanna Torres and Tom Paris on the  that their converter was rigged to explode when they crossed the finish line but Irina had damaged the comm system. He was able to alert them using a modulating pulse modified to mimic the Morse code he and Paris had used in the "Captain Proton" holonovels – "converter rigged: eject." ()

External links 
 
 

de:Morsecode
fr:Code morse
Communications technology
The Dixon Hill Series