Morse code

codes used for transmitting messages in which letters of the alphabet and numbers are represented by various sequences of dots and dashes or short and long signals.

Morse Code

letters:
A .-
B -...
C -.-.
D -..
E .
F ..-.
G --.
H ....
I ..
J .---
K -.-
L .-..
M --
N -.
O ---
P .--.
Q --.-
R .-.
S ...
T -
U ..-
V ...-
W .--
X -..-
Y -.--
Z --..

numbers:
1 .----
2 ..---
3 ...--
4 ....-
5 .....
6 -....
7 --...
8 ---..
9 ----.
0 -----

punctuation:
Full-stop (period) .-.-.-
Comma --..--
Colon ---...
Question mark (query) ..--..
Apostrophe .----.
Hyphen -....-
Fraction bar -..-.
Brackets (parentheses) -.--.-
Quotation marks .-..-.

.       E | -       T
..      I | -.      N
...     S | -..     D
....    H | -...    B
.....   5 | -....   6
....-   4 | -....-  -
...-    V | -..-    X
...--   3 | -..-.   /
..-     U | -.-     K
..-.    F | -.-.    C
..-..   É | -.-.-.  ;
..--    Ü | -.--    Y
..--..  ? | -.--.-  ()
..--.-  _ | --      M
..---   2 | --.     G
.-      A | --..    Z
.-.     R | --...   7
.-..    L | --..--  ,
.-..-.  " | --.-    Q
.-.-    Ä | --.--   Ñ
.-.-.-  . | ---     O
.--     W | ---.    Ö
.--.    P | ---..   8
.--.-   Á | ---...  :
.---    J | ----.   9
.----   1 | -----   0
.----.  ' | 

To make it easier, many folks use something called Farnsworth Code or Farnsworth Weighting. If you were sending a message to someone that understood morse at about 5 words per minute (WPM), you could send the dits and dahs at a higher rate but left more blank time between the letters. The white space between the letters allows the receiver to translate the morse.

Most morse code tests in the US use Farnsworth Weighting.

The United States FCC decided to go along with the rest of the world and lower the code test for amateur radio operators to five words per minute. With newer digital signaling technologies, morse is going by the wayside.

#!/usr/bin/perl -w

# This is a simple perl script to encode and decode morse
# code.  Files for decoding must use space-delimited crypts
# of dots and dashes

# USAGE: morse (d|e) files

%decodes=(
	'.-'	=>'A',	'-...'	=>'B',	'-.-.'	=>'C',	'-..'	=>'D',
	'.'	=>'E',	'..-.'	=>'F',	'--.'	=>'G',	'....'	=>'H',
	'..'	=>'I',	'.---'	=>'J',	'-.-'	=>'K',	'.-..'	=>'L',
	'--'	=>'M',	'-.'	=>'N',	'---'	=>'O',	'.--.'	=>'P',
	'--.-'	=>'Q',	'.-.'	=>'R',	'...'	=>'S',	'-'	=>'T',
	'..-'	=>'U',	'...-'	=>'V',	'.--'	=>'W',	'-..-'	=>'X',
	'-.--'	=>'Y',	'--..'	=>'Z',	'.----'	=>'1',	'..---'	=>'2',
	'...--'	=>'3',	'....-'	=>'4',	'.....'	=>'5',	'-....'	=>'6',
	'--...'	=>'7',	'---..'	=>'8',	'----.'	=>'9',	'-----'	=>'0',
	'.-.-.-'=>'.',	'--..--'=>',',	'---...'=>':',	'..--..'=>'?',
	'.----.'=>'\'',	'-...-'	=>'-',	'-..-.'	=>'/',	'.-..-.'=>'\"'
);

%encodes=();
while(@pair=each %decodes) {
	$encodes{$pair[1]}=$pair[0];
}

$mode=lc shift @ARGV;
decode() and exit if $mode =~ /d/;
encode() and exit if $mode =~ /e/;

sub decode {
	while(<>) {
		print ($decodes{$1} or '_') while s/^(.*?)\s+(.*)$/$2/;
		print "\n";
	}
	return 1;
}

sub encode {
	while(<>) {
		chop and $_=reverse;
		print ($encodes{uc $char} or '#') and print ' ' while $char=chop;
		print "\n"
	}
	return 1;
}

Samuel F. B. Morse, the inventor of the telegraph, did not invent the telegraphic code that now bears his name. Actually, today's morse alphabet is far removed from the system he envisioned for the telegraph. It consisted only of dots, which expressed numbers, and most common words and each letter had its own number. This is similar to the Dian-Ma codes used in Chinese telegraphy.

The one who introduced truly alphabetic telegraphy, with signals of differing duration (dot and dash) was Alfred Vail. He invented what was known as American Morse, which was used on landline telegraphs in the United States until the mid-20th century. But even this is not what is known as morse code today. What happened?

When telegraphy was introduced in Germany, the engineer Frederick Clemens Gerke was set with the task of translating Vail's book on telegraphy into German. He discovered that the alphabet could easily confuse the receiving operator, so he proceeded to simplify it. He removed differing intra-character spacings, and dashes of different lengths, so that he ended up with a morse code with only two element lengths (dot and dash), not unlike the present system.

Another few changes were made in the German and Austrian state telegraph convention of 1852, and the Paris International Telegraph Convention in 1856. This is the same morse code that was later adopted all over the world, except for a few minor changes in the punctuation characters that were enacted in 1939. This alphabet was known as "continental morse" or "international morse", but as American Morse faded away, it became simply known as "morse code", no qualifiers.

The current morse code consists of 5 code elements. These are the dot, the dash, the intra-character space, the inter-character space, and the inter-word space. Their duration depends on the speed of sending, but they have the same relative duration regardless of speed. This relative duration is based on the length of the dot.

• All elements in a character are separated by a period of silence equal in duration to a dot.
• One dash equals three dots.
• Characters are separated by a period of silence equal in duration to a dash.
• Words are separated by a period of silence equal in duration to two dashes.

Apart from this, telegraphy sent with computers or electronic keyers more or less perfectly follow standard element durations. It is particularly important not to lengthen intra-character spaces, or shorten inter-character ones, as this would make it very difficult to hear the character boundaries.

When printing code charts, it is customary to use markings that have the same relationship in length as the actual code elements have in duration. When this is not technically feasible, such as here on E2, the period and the hyphen-minus are used for the dot and the dash, respectively. Intra-character spacing is not given any written representation.

Letters:
A .-
B -...
C -.-.
D -..
E .
F ..-.
G --.
H ....
I ..
J .---
K, invitation to transmit -.-
L .-..
M --
N -.
O ---
P .--.
Q --.-
R, received .-.
S ...
T -
U ..-
V ...-
W .--
X -..-
Y -.--
Z --..
Á, Å .--.-
Ä, Æ .-.-
É ..-..
Ñ --.--
Ö, Ø ---.
Ü ..--

Numbers:
1 .----
2 ..---
3 ...--
4 ....-
5 .....
6 -....
7 --...
8 ---..
9 ----.
0 -----

Punctuation:
. (period) .-.-.-
, --..--
: ---...
? ..--..
' .----.
- (hyphen-minus) -....-
=, break -...-
/ -..-.
Brackets (parentheses) -.--.-
" .-..-.
; -.-.-.
_ ..--.-

Prosigns:
Beginning of message (KA) -.-.-
End of message (AR) .-.-.
Wait (AS) .-...
Understood (SN) ...-.
Error (correction of last word follows) ........
Distress signal (SOS) ...---...
Finish of transmission ...-.-

In the cases where there is more than one text character per code character, this means that it depends on context or language. For instance, .--.- means á in e.g. French messages, and å in e.g. Swedish messages.

Editor's note:The system described below is called American Morse Code, and is the original code developed by Samuel Morse. Unlike modern international morse code, American morse code made use of spaces inside of individual letters, such as O and C. These intra-letter spacings were eliminated with the development of international morse code in Germany in 1848, which changed the way the numbers and eleven of the letters were encoded. The new letters are given in the last section, but the new numbers are not. American morse code became obsolete in the 1960s. Please see the other writeups in this node for international morse code. This definition has been retained for its historic value.

Morse" code" (?). (Teleg.)

The telegraphic code, consisting of dots, dashes, and spaces, invented by Samuel B. Morse. The Alphabetic code which is in use in North America is given below. In length, or duration, one dash is theoretically equal to three dots; the space between the elements of a letter is equal to one dot; the interval in spaced letters, as O . ., is equal to three dots. There are no spaces in any letter composed wholly or in part of dashes.

Alphabet

A .-          H ....       O . .          V ...-

B - . . .     I ..         P .....        W .--

C .. .        J -.-.       Q ..-.         X .-..

D -..         K -.-        R . ..         Y .. ..

E .           L long dash  S ...          Z ... .

F .-.         M --         T --           & . ...

G --.         N -.         U ..-

Numerals

1 .--.        4 . . . .-          7 --..

2 ..-..       5 ---               8 - . . . .

3 . . . -.    6 . . . . . .       9 -..-

0 ----        Period ..--..       Comma .-.-

The International (Morse) code used elsewhere is the same as the above with the following exceptions.

C -.-.     L .-..     Q --.-     Y -.--

F ..-.     O ---      R .-.      Z --..

J .---     P .--.     X -..-

The Morse code is used chiefly with the electric telegraph, but is also employed in signalling with flags, lights, etc.

© Webster 1913