Magnetic core memory providing both non-alterable and electrically alterable locations

Claim 2

A magnetic core matrix comprising a plurality of bistable magnetic cores capable of storing first and second magnetic states, said cores arranged in a row and column matrix, each of said cores intersected by row and column selection wires and each of said cores selected by signals occurring simultaneously on the respective row and column selection wires, some of said cores oriented so that their magnetic state may be switched when selected and others of said cores oriented so that their magnetic state cannot be switched when selected, said others of said cores indicating said first state when selected regardless of which of said first and second states is stored therein.

Claim 3

A magnetic core matrix comprising: A. a plurality of magnetic cores; B. a plurality of row and column selection wires forming a plurality of crossover points, each of said wires intersecting and magnetically coupling to one of said cores at each of said crossover points; C. wherein some of said cores are oriented about said selection wires so that a change in magnetic state of said some of said cores may be effected; D. wherein others of said cores are oriented about said selection wires at random locations among said some of said cores so that a change in magnetic state of said others of said cores will not be effected when any one of said others of said cores is addressed for readout by signals occurring on the respective row and column selection wires; and E. a sense wire which intersects each of said cores in a selected direction.

Claim 4

A magnetic core matrix comprising: A. a plurality of magnetic cores; B. a plurality of row and column selection wires forming a plurality of crossover points, each of said wires intersecting and magnetically coupling to one of said cores at each of said crossover points; C. wherein some of said cores are oriented about said selection wires so that a change in magnetic state of said some of said cores may be effected; D. wherein others of said cores are oriented about said selection wires at random locations among said some of said cores so that a change in magnetic state of said others of said cores will not be effected when any one of said others of said cores is addressed for readout by signals occurring on the respective row and column selection wires; and E. a sense wire which intersects each of said cores in a selected direction.

Claim 5

A matrix as defined in claim 2 wherein said some of said cores are oriented diagonally about the crossover of said selection wires in a first magnetic coupling direction and wherein said others of said cores are oriented diagonally about the crossovers of said selection wires in a second magnetic coupling direction, said first and second magnetic coupling directions spaced substantially 90* apart.

Claim 6

A coincident current magnetic core memory comprising: A. a plurality of magnetic cores having a substantially rectangular hysterisis curve, said cores being arranged in rows and columns; B. a plurality of row selection wires adapted to receive half-select currents, each of said row selection wires intersecting a row of said cores; C. a plurality of column selection wires adapted to receive half-select currents, each of said column selection wires intersecting a column of said cores; D. means for generating said half-select currents on specified ones of said row and column selection wires in order to select one of said plurality of cores for readout; E. some of said cores oriented so that the receipt of half-select currents on corresponding row and column selection wires may cause a change in state of a first corresponding core selected for readout; and F. others of said cores oriented so that the receipt of half-select currents on corresponding row and column selection wires will not cause a change in state of a second corresponding core selected for readout.

Claim 7

A coincident current magnetic core memory comprising: A. a plurality of magnetic cores having a substantially rectangular hysterisis curve, said cores being arranged in rows and columns; B. a plurality of row selection wires adapted to receive half-select currents, each of said row selection wires intersecting a row of said cores; C. a plurality of column selection wires adapted to receive half-select currents, each of said column selection wires intersecting a column of said cores; D. means for generating said half-select currents on specified ones of said row and column selection wires in order to select one of said plurality of cores for readout; E. some of said cores oriented so that the receipt of half-select currents on corresponding row and column selection wires may cause a change in state of a first corresponding core selected for readout; and F. others of said cores oriented so that the receipt of half-select currents on corresponding row and column selection wires will not cause a change in state of a second corresponding core selected for readout.

Claim 8

A matrix as defined in claim 4 wherein said half-select currents on corresponding row and column selection wires of said first corresponding core add to produce a magnetic field capable of switching the state of said first corresponding core and wherein said half-select currents on corresponding row and column selection wires of said second corresponding core substantially cancel to produce a minimal magnetic field incapable of switching the state of said second corresponding core.

Claim 9

A magnetic core memory matrix including both non-alterable and alterable locations, said matrix comprising: A. a first plurality of magnetic cores in row and column matrix arrangement having row and column selection wires which each intersect one of said cores at each of the crossover points of said selection wires, said cores and selection wires arranged so that a change in state of said cores may be effected; B. a second plurality of magnetic cores in row and column matrix arrangement having row and column selection wires, said column selection wires of said second plurality of magnetic cores common to the column selection wires of said first plurality of magnetic cores, said row and column selection wires of said second plurality intersecting one of said second plurality of cores at each of the crossover points of said selection wires, said second plurality of cores and said selection wires arranged so that a change in state of some of said cores of said second plurality of cores may be effected when any of said some of said cores is addressed and so that a change in state of others of said cores of said second plurality of cores may not be effected when any of said others of said cores is addressed; and C. a sense wire which intersects each of said cores of said first and second plurality of cores in a selected direction.

Claim 10

A magnetic core memory matrix including both non-alterable and alterable locations, said matrix comprising: A. a first plurality of magnetic cores in row and column matrix arrangement having row and column selection wires which each intersect one of said cores at each of the crossover points of said selection wires, said cores and selection wires arranged so that a change in state of said cores may be effected; B. a second plurality of magnetic cores in row and column matrix arrangement having row and column selection wires, said column selection wires of said second plurality of magnetic cores common to the column selection wires of said first plurality of magnetic cores, said row and column selection wires of said second plurality intersecting one of said second plurality of cores at each of the crossover points of said selection wires, said second plurality of cores and said selection wires arranged so that a change in state of some of said cores of said second plurality of cores may be effected when any of said some of said cores is addressed and so that a change in state of others of said cores of said second plurality of cores may not be effected when any of said others of said cores is addressed; and C. a sense wire which intersects each of said cores of said first and second plurality of cores in a selected direction.

Claim 11

A matrix as defined in claim 6 wherein said some of said cores are oriented diagonally about the crossovers of said selection wires in a first magnetic coupling direction and wherein said others of said cores are oriented diagonally about the crossovers of said selection wires in a second magnetic coupling direction, said first and second magnetic coupling directions spaced substantially 90* apart.

Claim 12

A matrix as defined in claim 6 further including an inhibit wire which intersects each of said cores of said first plurality of cores in a magnetic coupling direction which may prohibit a change in state of said cores of said first plurality of cores.

Claim 13

A matrix as defined in claim 8 wherein said inhibit wire also intersects each of said cores of said second plurality of cores in a direction which may prohibit a change in state of said cores of said second plurality of cores.

Claim 14

A matrix as defined in claim 6 wherein said sense wire is magnetically coupled to one-half of said cores in a first direction and to the other half of said cores in a second direction whereby any noise generated on said sense wire due to currents through those cores not receiving a full selection current is substantially cancelled.

Claim 15

A matrix as defined in claim 10 wherein said sense wire is magnetically coupled to a column of said cores such that said noise developed therein will be substantially cancelled regardless of the orientation of said cores in said column of said cores.

Claim 16

A matrix as defined in claim 11 wherein said sense wire is magnetically coupled in one direction to one-half of said cores in said column of cores and is magnetically coupled in an opposite direction to the other half of said cores in said column of cores.