In 1947, Harvard’s Mark II ran on roughly 13,000 electromechanical relays, stored numbers across 100 registers, and read instructions from punched paper tape, turning thousands of clicking metal switches into a Navy calculator vulnerable to dust, loose contacts, and one famously misplaced moth
The famous moth in the Harvard logbook is often told as the origin of the word “bug” in computing. The truth is more interesting: the joke only works because engineers had already been calling faults bugs for more than sixty years.