Everyone is familiar with Morse Code where a character is represented by a sequence of long and short pulses - dots and dashes (dit and dah).
.-- .... .- - / .... .- - .... / --. --- -.. / .-- .-. --- ..- --. .... -
(The first official message sent by Samuel F.B. Morse on May 24, 1844, to open the Baltimore - Washington telegraph line).
Click the link for a Morse Code Translator