Apple’s latest iOS update has removed the “C” button from its Calculator app, replacing it with a backspace function. The change, part of iOS 18, has sparked debate among users accustomed to the traditional clear function. The removal of the “C” button represents a significant departure from decades-old calculator design conventions, The Atlantic writes. From the story: The “C” button’s function is vestigial. Back when calculators were commercialized, starting in the mid-1960s, their electronics were designed to operate as efficiently as possible. If you opened up a desktop calculator in 1967, you might have found a dozen individual circuit boards to run and display its four basic mathematical functions. Among these would have been an input buffer or temporary register that could store an input value for calculation and display. The “C” button, which was sometimes labeled “CE” (Clear Entry) or “CI” (Clear Input), provided a direct interface to zero out — or “clear” — such a register. A second button, “AC” (All Clear), did the same thing, but for other parts of the circuit, including previously stored operations and pending calculations. (A traditional calculator’s memory buttons — “M+,” “M-,” “MC” — would perform simple operations on a register.)
By 1971, Mostech and Texas Instruments had developed a “calculator on a chip,” which condensed all of that into a single integrated circuit. Those chips retained the functions of their predecessors, including the ones that were engaged by “C” and “AC” buttons. And this design continued on into the era of pocket calculators, financial calculators, and even scientific calculators such as the ones you may have used in school. Some of the latter were, in essence, programmable pocket computers themselves, and they could have been configured with a backspace key. They were not.
