Burroughs, Inc.

Texas Instruments Corporation

Magid Yousri Dimyan

John Charles Linn

Christopher T Chang

Carlos A Castro

Wayne C Hubbell

John C Unger

In a non-volatile random access memory, a selected one of a plurality of magnetic cells arranged in an array on a major surface of a substrate is inductively switched between opposite remanent, i.e. permanent, states upon the simultaneous application of electrical pulses to a pair of conductors intersecting adjacent the selected cell, each of the electrical pulses having an amplitude less than, but the sum thereof being at least equal to, the amplitude required to inductively switch the remanent state of the selected cell.

Magnetic domain random access memory

A magnetic bubble memory structure having an enhanced storage density is made possible by reducing the circuit period, that is the distance between bubbles, in the storage section of the device. This reduction of the circuit period is made possible by using a gap tolerant propagation element, e.g. asymmetrical chevrons. The bubble storage sections are structured such that the areas closest to the transfer gates have a larger circuit period than the remainder of the storage section. The bubble chip architecture utilizing this means of enhancing the storage density may be of the major-minor loop configuration or the block-replicate configuration. Bubble storage sections in the form of loop structures may have a folded loop or an h loop configuration as well as a closed loop configuration. The reduction in circuit period accomplishes enhancement of the storage density without reducing the bubble diameter and other minimum circuit features to achieve this goal.

Bubble memory structure with enhanced data density

An adjustable magnetic bias field structure for magnetic bubble devices. A pair of parallel facing magnetically permeable plates are adjustably separated by a number of threaded magnetically hard cylindrical rods or slugs slotted at one end. Threaded plastic rings fastened around holes provided in the pair of permeable plates engage the threads of the slotted rods to provide the adjustment feature. A magnetic bubble device is placed between the two permeable plates.

Adjustable magnetic bias field structure for magnetic bubble devices

A bubble lattice file comprising a plurality of propagate elements of magnetic film material positioned as an overlay over bubble supporting material with each element spaced from the bubble material such that a spacing gradient is formed between the element and the bubble material in the direction of the bubble propagation path. The elements comprising the main lattice memory file are arranged to support a hexagonal lattice of bubbles with one bubble propagation path in the form of rows and the other propagation path comprising accessing channels in the form of spaced apart columns. Utilizing the translation force on a bubble domain produced by the spacing gradient between the magnetic film and the bubble material, all bubbles in the lattice may be translated along the rows by a monopolar magnetic field applied in the row direction and when accessing is required, a monopolar field in the column direction is applied and all bubbles in equilibrium in the element of the rows which intersect the columns will move to the elements of the accessing channels and along its elements upon the continued application of the field ultimately exiting into a reading station. Concurrently, the read data may be reentered into the lattice at the entrance end of the columns.

Field access bubble lattice file device

A magnetic bubble expander-detector circuit comprising a pattern of magnetic material, forming Chevron elements positioned over a bubble-supporting material to define a bubble expander-detector circuit. Each element of the pattern is spaced from the bubble material such that a gradient is formed in the spacing between the element and the bubble material in the direction of the expansion and detection. A rotating magnetic field of sufficient strength to magnetize the pattern is applied in the plane of the material and the gradient of the spacing causes the bubbles to move from one element to an adjacent element as the bubbles are expanded and ultimately detected by suitable detection devices. This invention is particularly characterized in that, with the combination of the pattern elements and the gradient spacing thereof, gaps between adjacent elements are eliminated.

Gapless magnetic bubble expander-detector circuit

A magnetic bubble propagation device comprising a pattern of magnetic material formed of the so-called gap tolerant elements, positioned over a bubble supporting material to define a bubble propagation path. Each element of the pattern is spaced from the bubble material such that a gradient is formed in the spacing between the element and the bubble material in the direction of the propagation path. A rotating magnetic field of sufficient strength to magnetize the pattern is applied in the plane of the material and the spacing gradient causes the bubble to move from one element to an adjacent element in one complete field rotation. This device is particularly characterized in that, with the combination of the pattern elements and the spacing gradient thereof, the gaps between the elements are eliminated.

Growing community of inventors

San Diego, CA, United States of America

Magid Yousri Dimyan