5X5 Tap Code

This code was originally used as a way for prisoners of war, penal incaceration, and others to communicate with each other without individuals outside group knowing what is being said. It’s a short range communications system that only travels the length of the medium being sent on.

5 x 5 Tap Code is similar to Morse code in the sense that alphanumetric characters must be translated into a system of taps. The sounds can be made by tapping on anything available such as pipe, metal bars, the walls of a room or cell, or any object that can transmit the tapping. It can also be used with a Morse Code on-off sending key.

The code itself uses a square to make a 5×5 grid of letters in the English alphabet. Since the alphabet has 26 letters, C and K are both located in the top row third column spot to avoid an uneven grid.

In order to interpret the message, a listener must be able to gage the timing of the taps.

How To Use The Tap Code

To use this system each letter is identified by tapping two numbers.

The fist number designates the position in the down row, and is followed by a short pause.

The second number designates the column number, and is followed by a longer pause.

The letter X is use to break up sentences.

The letter K is used to acknowledge the message.

You can expect abbreviations in order to reduce the amount of time required to send the message.

As an example, to specify the letter “O” tap three times, very short pause, then tap four times, and a little longer pause.

To Spell Out The Word “HELP” In The 5X5 Tap Code

H E L P

2,3 1,5 3,1 3,5

.. … . ….. … . … …..