Visible Storage - samples from the collection
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Delay Lines

Williams Tubes

Core Memory

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Memory technology assortment
Credit: Computer History Museum

Main Memory

Early computer designers struggled to find a way to build fast random-access memory devices to store data and instructions. Some of their early attempts are shown here. Delay lines were pipes filled with mercury in which data was circulated as acoustic waves. Williams tubes were cathode ray display tubes with data written as spots of light that needed to be read and rewritten before they faded. In the early 1950s Jay Forrester, working on the MIT Whirlwind computer project, perfected core memory: small magnetized ferrite donuts that each store a single bit of data. Core became the dominant form of computer memory until semiconductor memories arrived in the 1970s.

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