ENIAC materialized general-purpose electronic computing. Publicly presented on 14 February 1946, it was the first electronic digital computer able to solve different problems without being mechanically redesigned — though reprogramming required hours of physical cable reconfiguration. Its 18,000 vacuum tubes made it thousands of times faster than any prior mechanical calculator. It was initially programmed by six mathematicians — Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Meltzer, Fran Bilas, and Ruth Lichterman — whose contribution was publicly ignored for decades. ENIAC demonstrated that electronic computing was viable at scale; von Neumann's stored-program architecture would make later computers radically more flexible.