szczys writes: The Pari-Mutuel system revolutionized how wagers were made on horse races starting in the late 1800s. It moved away from gambling against the house, and adjusted the odds based on how many people were placing wagers on a particular horse. Calculating and publicly displaying the changing odds was slow and labor intensive until engineers took a crack at the problem. They created Tote Boards; large mechanical computers which connected to each betting window with levers and cables. Each pull of a lever recalculated the odds which were displayed on large mechanical displays for all to see. Tote Boards were built all over the world and used until digital computing displaced them.