Today, when nearly every device is available in a portable, pocket-sized version, it is hard to imagine a time when a simple, handheld calculator was the stuff of science fiction. In the early 1960s, calculators were the size of modern-day desktop computers but not nearly as powerful. Personal calculators were nonexistent, and workplace desktop calculators were limited to four simple arithmetic functions. In the workplace, complex math was left to humans.
In 1965, mathematicians and engineers at Texas Instruments (Tl) set to work shrinking calculators, using integrated circuit technology that had been invented in-house. By 1967, they had a battery- powered prototype capable of the four simple arithmetic functions on six-digit numbers. Dubbed "Cal-Tech," the calculator was the size of a large paperback book—4.25 x 6.15 x 1.75 inches (11 x 16 x 4cm)—and weighed nearly 3 pounds (1.3 kg)—hardly a "pocket calculator" and not commercially available or viable. Tl
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