Jay Forrester filed the first practical computer RAM patent 75 years ago this week — his Magnetic Core Memory patent would be granted five years later
Seventy-five years ago, MIT engineer Jay Forrester filed a patent for coincident-current magnetic core memory, a breakthrough that became the dominant form of computer RAM for two decades. The patent, granted in 1956, stemmed from Project Whirlwind and enabled reliable real-time computing for Cold War air defense systems. Legal disputes followed, culminating in a record $13 million settlement paid by IBM to MIT in 1964.
- ▪Jay Forrester filed the patent for magnetic core memory on May 11, 1951, which was granted in February 1956 as U.S. Patent 2736880.
- ▪The technology originated from MIT's Project Whirlwind, which required reliable memory for real-time air defense computing during the Cold War.
- ▪Forrester's design used ferrite rings strung on a grid of wires to store data via magnetic polarization, enabling scalable and durable random-access memory.
- ▪IBM settled with MIT in 1964 for $13 million, the largest patent payout at the time, after years of legal challenges to Forrester's patent.
- ▪MIT's detailed documentation of lab work and timelines helped establish Forrester's priority over competing claims from RCA and An Wang.
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Tech Industry Jay Forrester filed the first practical computer RAM patent 75 years ago this week — his Magnetic Core Memory patent would be granted five years later News By Luke James published 17 May 2026 The patent sparked the largest settlement in history at the time. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. 2Kb of memory (Image credit: Daderot on Wikipedia) Copy link Facebook X Whatsapp Reddit Pinterest Flipboard Email Share this article 0 Join the conversation Follow us Add us as a preferred source on Google Newsletter Subscribe to our newsletter 75 years ago this week, on May 11th, 1951, MIT electrical engineer Jay Forrester filed the patent application for coincident-current magnetic core memory, a technology that became…
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