Starting about 1955, David Florida drove the development of a computer using Moody's flip-flop design. He examined existing computer designs and concluded that the main limitation in computer complexity was due largely to the burnout rate of the tubes; a more powerful design required more tubes, which meant more frequent burnouts. Although a number of truly massive machines had been built, like SAGE, most machines were much smaller in order to improve uptime. With transistors this limitation was removed; more complex machines could be built with little effect on reliability, as long as one was willing to pay the price for more transistors. With the price of transistors falling all the time, Florida's design included every feature he imagined would be useful in a scientific machine.