I was watching a video of little kids trying to figure out how to use a rotary phone, and it was not immediately clear to any of them how the rotary mechanism was supposed to work. That got me thinking: why was the rotary mechanism used in phones at all? It seems like individual buttons would be more intuitive to everyone and might even have less mechanical problems than a thing that has to rotate thousands and thousands of times over it's lifetime. Why was that design choice made, why were they popular, and why did they stick around so long even after phones with buttons came on the market?
edit: The first touch tone phone was introduced by AT&T in 1963. Even though integrated circuits weren't practical for commercial use at that time, apparently transistors were:
By the early 1960s, low-cost transistors and associated circuit components made the introduction of touch-tone into home telephones possible. Extensive human factors tests determined the position of the buttons to limit errors and increase dialing speed even further. The first commercial touch-tone phones were a big hit in their preview at the 1962 Seattle World's Fair. (1)
The fact that Bell Labs had invented the transistor probably helped that process along. And I understand that the change in how telephone networks worked (from pulse dialing to DTMF) drove a change in the electrical design of phones. But while transistors let them make that protocol change, was it really impossible to implement pulse dialing using buttons but not transistors? From Wikipedia:
In the 1950s, AT&T conducted extensive studies of product engineering and efficiency and concluded that push-button dialing was preferable to rotary dialing (2).
That suggests the designers did not know that buttons were better than a dial (if they did know, why would they have done such extensive studies?). It also suggests that it WAS possible to make a phone with buttons. They would have had to build button prototypes for their studies, right?