Morse Code vs Tap Code: Key Differences, History, and Modern Uses

When it comes to secret communication and encoding systems, Morse code and Tap code are two of the most fascinating methods ever developed. Both were designed to transmit messages without the need for traditional spoken language, relying instead on patterns of sound, light, or tapping. While they share similarities, their origins, complexity, applications, and usability differ greatly.

This article provides a detailed comparison of Morse code vs Tap code, covering their history, mechanics, pros and cons, and how each is used today.

What is Morse Code?

Morse code was developed in the 1830s by Samuel Morse and Alfred Vail. It encodes letters, numbers, and punctuation using a series of dots (·) and dashes (–). Each character has a unique sequence, making it highly versatile and widely adopted in telegraphy, radio communication, and emergency signaling.

For example:

• A = · –
• B = – · · ·
• SOS = · · · – – – · · ·

Morse code can be transmitted through sound, flashing lights, or written marks, which makes it highly adaptable.

What is Tap Code?

Tap code, also known as the Knock Code, is a simpler system used primarily by prisoners of war (POWs) to secretly communicate. It is based on a Polybius square, where letters are arranged in a 5×5 grid.

Each letter is transmitted using two sets of taps:

• The first set of taps indicates the row.
• The second set of taps indicates the column.

Example Polybius Square (C and K are merged into one cell):

1

2

3

4

5

1

A

B

C/K

D

E

2

F

G

H

I

J

3

L

M

N

O

P

4

Q

R

S

T

U

5

V

W

X

Y

Z

To communicate "HI", the taps would be:

• H = Row 2, Column 3 → Tap Tap (pause) Tap Tap Tap
• I = Row 2, Column 4 → Tap Tap (pause) Tap Tap Tap Tap

Morse Code vs Tap Code: A Quick Comparison Table

Feature

Morse Code

Tap Code

Origin

1830s (Samuel Morse & Alfred Vail)

Used widely during 20th-century wars, especially by POWs

Encoding Method

Dots (·) and Dashes (–)

Taps based on Polybius Square (5×5 grid)

Characters Supported

Letters, numbers, punctuation

Only letters (no numbers/punctuation)

Complexity

Complex but precise

Simple and easy to learn

Speed

Faster once mastered

Slower for long messages

Transmission Mediums

Sound, light, radio, writing

Physical tapping (walls, pipes, tables)

Learning Curve

Moderate to difficult

Easy (learned in minutes)

Modern Uses

Aviation, radio, emergency SOS

Secret communication, historical interest

Historical Context

Morse Code in Communication History

Morse code revolutionized long-distance communication during the telegraph era. It enabled messages to be sent across continents in seconds, something unheard of before its invention. Later, it played a vital role in maritime safety, including the famous SOS distress signal. Even during World War II, Morse code operators were crucial for military communication.

Tap Code in Wars and Prisons

Tap code became famous during the Vietnam War, where American prisoners of war used it to communicate secretly despite being isolated in cells. The system’s simplicity made it perfect for tapping on walls, pipes, or bars, allowing prisoners to exchange morale-boosting messages and maintain unity.

How They Work: A Side-by-Side Look

Morse Code Example

Message: HELLO

• H = · · · ·
• E = ·
• L = · – · ·
• L = · – · ·
• O = – – –

Morse Code Output: ···· · ·–·· ·–·· –––

Tap Code Example

Message: HELLO

• H = Row 2, Column 3 → Tap Tap (pause) Tap Tap Tap
• E = Row 1, Column 5 → Tap (pause) Tap Tap Tap Tap Tap
• L = Row 3, Column 1 → Tap Tap Tap (pause) Tap
• L = Row 3, Column 1 → Tap Tap Tap (pause) Tap
• O = Row 3, Column 4 → Tap Tap Tap (pause) Tap Tap Tap Tap

Tap Code Output: (2,3) (1,5) (3,1) (3,1) (3,4)

Advantages of Morse Code

• Supports numbers, punctuation, and prosigns.
• Versatile (usable with sound, light, or writing).
• Recognized globally (especially SOS).
• Faster for experienced operators.

Advantages of Tap Code

• Extremely simple and quick to learn.
• Does not require special equipment.
• Works in confined spaces like prisons or bunkers.
• Excellent for covert communication.

Limitations of Morse Code

• Steeper learning curve.
• Requires precision (mistakes change meaning).
• Not ideal in noisy or distracting environments without proper equipment.

Limitations of Tap Code

• No support for numbers or punctuation.
• Relatively slow for long conversations.
• Limited recognition outside military or POW history.

Modern Applications

Morse Code Today

• Still used in aviation and amateur radio.
• SOS distress signal remains universally recognized.
• Increasingly used in education, puzzles, and accessibility tools (e.g., for people with disabilities to communicate).

Tap Code Today

• Primarily studied for historical and educational purposes.
• Sometimes used in escape rooms, survival training, and cryptography exercises.
• Symbol of resilience among former POWs.

Detailed Feature Comparison Table

Aspect

Morse Code

Tap Code

Ease of Learning

Requires practice to master timing of dots and dashes

Can be learned in minutes

Message Speed

Faster with experience

Slower

Error Tolerance

High precision needed

More forgiving

Global Use

Widely known and standardized

Limited use, mainly historical

Transmission Tools

Telegraphs, radios, lights, sound signals

Surfaces like walls, pipes, tables

Best Use Case

Long-distance, complex communication

Secret, low-tech communication

Which is Better: Morse Code or Tap Code?

The answer depends on context:

• If you need speed, versatility, and universal recognition, Morse code is superior.
• If you need simplicity and secrecy in confined environments, Tap code is the winner.

In reality, both systems hold historical significance and highlight the ingenuity of humans in developing ways to communicate under constraints.

Conclusion

The debate of Morse code vs Tap code isn’t about which one is universally better, but rather about where and how each shines. Morse code changed the world by revolutionizing global communication, while Tap code offered hope and connection in the darkest times of captivity.

Both remain fascinating examples of human resilience, adaptability, and the need to connect, making them timeless subjects of study in communication history.