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 could also be built with a non-destructive read that did not require refreshing.

Plated wire memory has been used in a number of applications, typically in aerospace. It was used in the UNIVAC 1110 and UNIVAC 9000-series computers, the Viking program that sent landers to Mars, the guidance computer of the Minuteman 3, and in the Hubble Space Telescope.