Plated-wire memory

Plated wire memory is a variation of core memory developed by Bell Laboratories in 1957. Its primary advantage was that it could be machine-assembled, which potentially led to lower prices than the hand-assembled core.

Instead of threading individual ferrite cores on wires, plated wire memory used a grid of wires coated with a thin layer of iron-nickel alloy (called permalloy). The magnetic field normally stored in the ferrite core was instead stored on the wire itself. Operation was generally similar to core, but also featured a non-destructive read that did not require refreshing.

Plated wire memory has been used in a number of application, typically in aerospace. It was used on the Viking program that sent landers to Mars, and apparently in the Hubble Space Telescope as well.