资料来源 : Free On-Line Dictionary of Computing
ferrite core memory
(Or "core") An early form of {non-volatile storage}
built (by hand) from tiny rings of magnetisable material
threaded onto very fine wire to form large (e.g. 13"x13" or
more) rectangluar arrays. Each core stored one {bit} of data.
These were sandwiched between {printed circuit boards}(?).
Sets of wires ran horizontally and vertically and where a
vertical and horizontal wire crossed, a core had both wires
threaded through it.
A single core could be selected and magnetised by passing
sufficient current through its horizontal and vertical wires.
A core would retain its magnetisation until it was
re-magnetised. The two possible polarities of magnetisation
were used to represent the binary values zero and one.
A third "sense" wire, passed through the core and, if the
magnetisation of the core was changed, a small pulse would be
induced in the sense wire which could be detected and used to
deduce the core's original state.
Some core memory was immersed in a bath of heated oil to
improve its performance.
Core memory was rendered obsolete by {semiconductor} memory.
For example, the 1970s-era {NCR 499} had two boards, each with
16 {kilobytes} of core memory.
(1996-03-04)