“Thacker wondered. Given the way prices were falling and processor speeds were rising, why not just build a bunch of very simple controllers and then let the computer’s central processor use software to do all the really hard work of input and output? The result would be a kind of internal time-sharing, Thacker realized. The processor would still cycle very, very quickly among all its users, but now only one of those users would be human; the rest would be input/output devices. “The payoff,” he explains, “would be an enormous simplification of the machine.”