The "Butterfly keyer" program converts the Butterfly demo board into an Iambic keyer which can decode and display the characters you send using the paddle. This forces you to have proper letter and word spacing, otherwise the letters will not decode or there will be no spaces between words. One of the most common errors both Novices and Old Timers alike make when sending Morse is running their letters and words together, so its hard for someone trying to copy your sending to tell when a letter stops or a word starts. The Butterfly keyer can also help you with learning to copy Morse code, as it can send random 5 character groups, then display the characters so you can check your copy. The keyer also features selectable 5 to 40 wpm code speeds in 1 wpm steps, selectable A or B Iambic modes and two 63 character message memories.