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:
“God damnit, why must all those journalists be such sticklers for detail? Why, they’d hold you to an accurate description of the first time you ever made love, expecting you to remember the color of the room and the shape of the windows.”
—Lyndon Baines Johnson (1908–1973)
“Once a child has demonstrated his capacity for independent functioning in any area, his lapses into dependent behavior, even though temporary, make the mother feel that she is being taken advantage of....What only yesterday was a description of the child’s stage in life has become an indictment, a judgment.”
—Elaine Heffner (20th century)
“The type of fig leaf which each culture employs to cover its social taboos offers a twofold description of its morality. It reveals that certain unacknowledged behavior exists and it suggests the form that such behavior takes.”
—Freda Adler (b. 1934)