Keyer

A keyer is an electronic device used for signaling by hand, by way of pressing one or more switches. The technical term keyer has two very similar meanings, which are nonetheless distinct: One for telegraphy and the other for accessory devices built for computer-human communication:

• For radio-telegraphy, the term "keyer" specifically refers to a device which converts signals from an "iambic" type or "sideswiper" type telegraph key into Morse code for transmission, but excludes the key itself.
• For computer human interface devices, "keyer" generally refers to both a single-hand multi-switch and the electronics which interpret the user key-presses and send the corresponding signals to the computer.