Flag Semaphore Simulator

This page demonstrates the concept of optical telegraphy, a predecessor of modern electrical signal processing. See Wikipedia: Flag semaphore for more details.

To run the simulation, enter some text into the input box below and click on the Signal! button. It will signal "Attention" followed by your message.

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Copyright © 2021 by Thomas Heller [ˈtoːmas ˈhɛlɐ]