An invention before 20 century. The telegraph.

This device was invented by Samuel Morse, the system lacked a code for comunication, but soon both created an alphabet based on the amplitude of the signals giving it a real ability to communicate his invention. When the radio station the switch is closed, current flows from battery power to the line and the electromagnet, which makes it attracted a metal finished in a punch press a strip of paper which is moved by rollers drive, driven by a clockwork mechanism on a cylinder impregnated whit ink, so that, depending on how long you press the switch, will result in the printing of a dot or a line on the strip. The bcombination of dots and dashes on paper can be translated into alphanumeric charactersthrought the use of an agreed, in practice the most widely used for many years has been the Morse code. ALG