Jay Forrester
The engineer behind Whirlwind who gave the computer a memory it could trust — then changed fields entirely.
Jay Wright Forrester (1918–2016) led the Whirlwind project at MIT, a real-time computer that began as a flight simulator and became a proving ground for fast, reliable computing. The bottleneck was memory: Williams tubes and delay lines were too slow and too flaky for real time. Forrester's answer, coincident-current core memory, stored each bit in a tiny magnetic ferrite ring addressed by crossing wires. It became the industry's standard memory for two decades.
He patented the design and defended it through a long priority fight with An Wang and others over who had really invented what. In the 1950s Forrester left hardware altogether and founded system dynamics — a way of modelling cities, firms and whole economies as feedback systems. He taught at MIT Sloan into the 2000s.