Modern historians count 1967 as an especially busy year: the six‑day war, the summer of love, Sgt Pepper, the first recorded deaths of American astronauts, the founding of the suburban utopia of Milton Keynes. And also, half-forgotten in the crush, perhaps the most consequential event of all: the invention of the first device ever that permitted us to henceforward stop using a part of our brains.
A young Dallas engineer named Jerry Merryman and his team gave us, courtesy of his employers, Texas Instruments, the Cal-Tech electronic calculator. For $400 you could own a shirt-pocket-sized plastic box with buttons and symbols that, if pressed, would answer in an instant, and with impeccable accuracy, any simple arithmetical question you might ask it. And most important, it performed its work invisibly. The abacus and the slide rule might have been mental labour-saving devices, but they still required you to make some use of your grey matter; the Cal-Tech freed you up entirely, removing all mathematical tedium from your daily life.
