How it works
Text to Morse and back
Each letter, digit and common punctuation mark is looked up in the International Morse table (ITU-R M.1677-1), plus the widely used extras for !, &, _ and $. Letters are separated by a space and words by a slash.
In Auto, the tool decodes when the input contains only dots, dashes, slashes and spaces, and encodes anything else. Decoding accepts · and • for dots and –, — or _ for dashes, and treats a slash or three spaces as a word gap. A code that is not in the table comes back as �.
Timing and speed
Speed is set in words per minute using the PARIS standard: the word PARIS plus its trailing gap is 50 units, so one unit lasts 1200 ÷ WPM milliseconds. A dot is one unit, a dash three, the gap inside a letter one, between letters three and between words seven.
unit (ms) = 1200 ÷ WPM
Playback and the tape
Play builds the whole message as a 600 Hz sine tone with 2 ms fades on each mark (so it does not click), then plays it through the Web Audio API. Loop repeats it with a word gap between passes. The tape draws every mark at its true length and lights each one as it sounds.
The keypad types dots, dashes and gaps and sounds each mark as you press it. With a key focused you can also use the . and - keys, space for a letter gap and / for a word gap.
