At Manchester University, Freddie Williams and Tom Kilburn develop the Williams-Kilburn tube. The tube, tested in 1947, was the first high-speed, entirely electronic memory. It used a cathode ray tube (similar to an analog TV picture tube) to store bits as dots on the screen’s surface. Each dot lasted a fraction of a second before fading so the information was constantly refreshed. Information was read by a metal pickup plate that would detect a change in electrical charge.