[computer] QWERTY keyboard is widely used for information processing nowadays in Japan, United States, and other countries. And the most frequently asked question about the keyboard is: “Why are the letters of the keyboard arranged the way they are?” Several papers in the field of information processing answer the question like this: “To slow down the operator.” It’s nonsense. In this paper we reveal the prehistory of QWERTY keyboard along the history of telegraph apparatus: Morse, Hughes-Phelps, and Teletype.