Miscellany № 38: the alternate history of the telephone keypad
Publication and its attendant excitements have taken up much of the past month, and I have a stack of punctuation-related matters to catch up with. Without further ado, let’s get on with the show!
Readers of Shady Characters (whether in book or blog form) will recall that the octothorpe (#) came by its rather esoteric name courtesy of the creation, in the 1950s, of the push-button telephone keypad. The engineers of Bell Labs had designed a 4 x 4 grid of buttons where each row and column was assigned a unique audible frequency; when pressed, a button produced a tone composed of the frequencies corresponding to its location on the grid. Early production handsets had only ten buttons — the digits 0–9, arranged in the familiar inverse-calculator layout — while later versions added ‘*’ and ‘#’ buttons to yield a neat 3 x 4 grid. (Military and other speciality handsets used all four columns.) The story, as told by two separate Bell Labs employees, goes that there was no unambiguous name for the ‘#’ and so, for the purposes of training and documentation, it was necessary to invent one: “octothorpe” was the result, and its place on the soon-to-be ubiquitous telephone keypad assured its survival into the future.