A coding system invented by Samuel A. Morse, for use in sending character data over extremely low-quality pathways -- such as telegraphs and low-quality radio. Morse code expresses characters as pulses of different durations. Short signals are called "dots" and long signals are calles "dashes". The coding assigns shorter sequences to the most frequently used characters.

American Morse code is the first and original Morse code character set. Character sets adapted to other languages were developed later.

American Morse Code:

 A . __        J . .          S . . .       1 . __ __ .
 B __ . . .    K __ . __      T __          2 . . __ . .
 C . .  .      L ___          U . . __      3 . . . __ .
 D __ . .      M __ __        V . . . __    4 . . . . __
 E .           N __ .         W . __ __     5 __ __ __
 F . __ .      O .  .         X . __ . .    6 . . . . . .
 G __ __ .     P . . . . .    Y . .  . .    7 __ __ . .
 H . . . .     Q . . __ .     Z . . .  .    8 __ . . . .
 I . .         R .  . .       0 ____        9 __ . . __

Where . is a short pulse, __ a long pulse, ___ a very long pulse and ____ a extra long pulse. There are also long and short spaces character-internal. Intercharacter spaces are very long and interword spaces are extra long. There is no standarisation in these durations, and they vary depending on the coder's preference and on the quality of the line.

Continental Morse Code or International Morse Code is a widely used de-facto standard. This table summarises the Western European usage of Continental Morse Code:

A .- G --. M -- S ... Y -.-- 4 ....-

B -... H .... N -. T - Z --.. 5 .....

C -.-. I .. O --- U ..- 0 ----- 6 -....

D -.. J .--- P .--. V ...- 1 .---- 7 --...

E . K -.- Q --.- W .-- 2 ..--- 8 ---..

F ..-. L .-.. R .-. X -..- 3 ...-- 9 ----.

A-umlaut (1) .-.- E-acute ..-..

A-acute .--.- N-tilde --.--

A-corona (11) .--.- O-umlaut (1) ---.

CH (2) ---- U-umlaut (1) ..--

Punctuation Marks: Other Signs:

period .-.-.- warning .-..-

comma --..-- error ........

question mark ..--.. repetition (ii ii) .. ..

hyphen -....- wait (AS) .-...

colon (3) ---... interruption (BK) -...-.-

underline (4) ..--.- understood (VE) ...-.

apostrophe .----. transmission received (R) .-.

quotation mark .-..-. beginning of message (KA) -.-.-

parenthesis open (5)-.--. end of message (AR) .-.-.

parenthesis (close) -.--.- end of transmission (K) (6) -.-

equal sign (7) -...- end of transmission (KN) (8) -.--.

plus sign .-.-. closing mark (SK) (9) ...-.-

multiplication sign -..- closing station (CL) -.-..-.

fraction mark -..-.

separator (10) .-..-

(1) Note: 'umlaut' is also known as 'diaeresis'

(2) Used only in German; not in Dutch.

(3) also: 'divided by'

(4) before and after the word to be underlined

(5) purportedly replaced by -.--.- for both "(" and ")"

(6) both and invitation to any station to start transmission

(7) also used as spacing between parts of transmission

(8) also an invitation to one station in particular to start

transmission

(9) connection will be closed.

(10) in fractions, for example.

(11) A-ring ?

Where '.' is a short pulse, '-' a long one. A '-' is three times as long as a '.'; character-internal spaces are as long as '.'s. Intercharacter space are as long as -'s. Spaces between words are as long as seven '.'s.