Morse Code  There are at least two versions, the international and US National, and there are addtional codes for commonly used whole words, some of these are called Q-codes.  In the discussion ,which is an introduction both linked ideas of information and efficient coding,, I have just concentratied on capital letters A,..,Z.

Here are some web sites for Samuel Morse, including some pictures of telegraph keys,  that were current as of Jan 27, 1999

1837ad.htm ,      samuel.htm ,     SamMorse.html ,      MorseKey.html ,     SCmorseCirc.html ,
 Western Union

Example coding: Morse Code.
Symbol Morse Code Binary
Equiv
Dec.
Equiv
Frequency1 Rank2 Probability
----------- One Bit --------
E . 0 0 3826 1 0.117
T - 1 1 3169 2 0.097
----------- Two Bits --------
I .. 00 0 2620 4 0.080
A .- 01 1 2823 3 0.086
N -. 10 2 2142 8+ 0.066
M -- 11 3 865 14+ 0.026
----------- Three Bits --------
S ... 000 0 2181 7 0.067
U ..- 001 1 796 16 0.024
R .-. 010 2 2372 6- 0.073
W .-- 011 3 311 21 0.010
D -.. 100 4 1153 11 0.035
K -.- 101 5 88 23 0.003
G --. 110 6 574 18 0.018
O --- 111 7 2590 5- 0.079
-----------Four Bits --------
H .... 0000 0 1112 12- 0.034
V ...- 0001 1 339 20 0.010
F ..-. 0010 2 814 15 0.025
L .-.. 0100 4 1333 9- 0.041
P .--. 0110 6 939 13- 0.029
J .--- 0111 7 18 26 0.001

B

-... 1000 8 506 19 0.015
X -..- 1001 9 71 24 0.002
C -.-. 1010 10 1320 10- 0.040
Y -.-- 1011 11 577 17 0.018
Z --.. 1100 12 23 25 0.001
Q --.- 1101 13 88 22 0.003


1 Characters were abstracted from three articles appearing in 1998 issues of the Journal of the American Medical Association. Total characters: 32650. Expected Character Length = 2.533 bits. If code optimization is done by reassigning characters to symbols (on the basis of the ranks) then: Minimum ECL = 2.384; Maximum ECL 3.793.

Assuming 40 lines of 65 charaters each in a page of text or a 2600 character message Morse code length is 6586 bits, best is 6198 (6% shorter) worst 9861 (50%) longer. Computer storage is 8 bits per character or 316% longer. Which explains why fast modems use data compression.