Description
The term "core" comes from conventional transformers whose windings surround a magnetic core. In core memory the wires pass once through any given core—they are single-turn devices. The magnetic material for a core memory requires a high degree of magnetic remanance, the ability to stay highly magnetized, and a low coercitivity so that less energy is required to change the magnetization direction. The core can take two states, encoding one bit, which can be read when "selected" by a "sense wire". The core memory contents are retained even when the memory system is powered down (non-volatile memory). However, when the core is read, it is reset to a "zero" which is known as destructive readout. Circuits in the computer memory system then restore the information in an immediate re-write cycle. The properties of materials used for memory cores are dramatically different from those used in power transformers.
Read more about this topic: Magnetic-core Memory
Famous quotes containing the word description:
“The great object in life is Sensationto feel that we exist, even though in pain; it is this craving void which drives us to gaming, to battle, to travel, to intemperate but keenly felt pursuits of every description whose principal attraction is the agitation inseparable from their accomplishment.”
—George Gordon Noel Byron (17881824)
“As they are not seen on their way down the streams, it is thought by fishermen that they never return, but waste away and die, clinging to rocks and stumps of trees for an indefinite period; a tragic feature in the scenery of the river bottoms worthy to be remembered with Shakespeares description of the sea-floor.”
—Henry David Thoreau (18171862)
“A sound mind in a sound body, is a short, but full description of a happy state in this World: he that has these two, has little more to wish for; and he that wants either of them, will be little the better for anything else.”
—John Locke (16321704)