Magnetic-core Memory

The term “magnetic-core memory” refers to any one of a class of computer memory devices that consists of a large array of tiny toruses made of a hard magnetic material that can be magnetised in either of two directions. Other names for this type of memory include “core memory” and “magnetic-core storage.” Both of these directions have the potential to represent either the value 0 or the value 1 in a binary bit. In the 1950s, magnetic core memory began to see extensive use, but by the 1970s, it had been mostly rendered obsolete by semiconductor memory chips. Several variations of core-store memory were used to build the Apollo 11
guidance computers.