Magnetic Core memory was the RAM at the heart of many computer systems through the 1970s, and is undergoing something of a resurgence today since it is easiest form of memory for an enterprising ha… ...

Magnetic core memory should not be confused with core-rope memory, which was a ROM solution of similar vintage. The legendary Apollo Guidance Computer used both.

Core memory was invented in the early '50s, but it did not replace magnetic drums (and volatile vacuum tube storage) until the '60s when it became cheap enough to manufacture. [Image credit ...