Home Reference Codes and Secret Messages

Codes, Decoding and Secret Messages: How codes are used, and different types of codes, including morse code, computer codes, and more.


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Morse Code Informational Page

Morse Code was designed by Samuel Morse and Alfred Vail. It uses short and long pulses - tones or lights - to represent letters and numbers. Probably the most well known Morse Code Message is the one made up of three short pulses, then three long pulses, then three short pulses again. Or "dot dot dot, dash dash dash, dot dot dot." This message means "S O S" (S = "..." and O is "---"), the distress signal.

Officially, the short and long pulses are called "dits" and "dahs", but we like to call them "dots" and "dashes" anyway.

Samuel Morse and Alfred Vail also developed a telegraph machine, which is what is used to send Morse Code messages. A telegraph operator sits at the machine and taps out long and short taps to represent the letters of the message he's sending. I imagine it must take a lot of concentration and a very good memory to keep track of all those dots and dashes!

The very first telegraph message ever sent was a short one, but very interesting. The message was: "What God Hath Wrought". You may want to try putting that message in the encoder to see what it looks like!

Here's a list of the letters and numbers, as well as the series of dots and dashes for each one. Before you look at it, think about this. In order to save time, the shortest sequences should be used for the letters which are most commonly used, right? So which letters do you think are "dot" and "dash"? Check the list below to see if you're right!

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