Abstract: A set of three input, three output bubble logic gates forms all of the possible distinct output functions for conservative three variable gates. The magnetic interaction between single wall domains propagating through separate channels defined by closely spaced circuit element paths causes the domains to switch to or remain on alternate paths via between-path transfer means in a predetermined fashion. In addition to vertically graded element transfer means, several new circuit arrangements are introduced including non-graded elements, strong and weak S-curves, elements having uneven gradation, and other circuit techniques. A group of primitive realizations are described which can be combined to produce other gates having output functions in each of 31 equivalence classes. A methodology for using the gates in logic design is suggested, and several new building block gates producing functions of two variables are presented.

Abstract: Composite mutually exclusive field-accessed circuit elements common to a plurality of bubble paths. A channel composed of mutually exclusive circuit elements is linked to an adjacent parallel channel of mutually exclusive circuit elements by means of circuit element portions common to both channels. The interconnected channels are operated mutually exclusively by means of corresponding pulsed field sequences. Transfer between the linked channels is via the common circuit element portion. Several new types of propagation circuits are also discussed along with organizations for mutually exclusive major and minor closed loops featuring controlled transfer via common circuit element portions.

Abstract: Magnetic bubble logic circuits performing the functions of various forms of flip-flops and decoders are presented. Set-reset and trigger flip-flops are constructed from specialized 3--3 conservative bubble logic circuits. Two forms of tree-type decoders employing crossovers of bubble tracks are illustrated for generating all possible product permutations of a plurality of input variables. Planar decoders and cross point circuits without crossovers are combined in matrix form to provide a multi-variable decoder without internal crossovers.

Abstract: A technique for enhancing readout of magnetic bubble data by producing two separate, complementary multiplicities of bubbles representing respectively the presences and the absences of bubbles in a data stream. A pair of detectors register the presence of the respective multiplicities of bubbles. The outputs of the detectors are compared to produce a single output indicative of the presence or absence of the original data bubble. In one embodiment a bubble logic gate causes a single bubble bit in the data stream to logically influence a train of bubbles in a separate closed circuit operating at a rate which is a multiple of the rate of the data stream. Depending on the presence or absence of a bubble in the data stream, the train of bubbles is directed to one or the other of a pair of magnetoresistive elements spanning the length of the train of bubbles. The magnetoresistive elements form part of a balanced bridge circuit.

Abstract: Parallel "crow-foot" circuit elements in different bubble paths symmetrical about an axis parallel to and between the paths propagate bubbles in opposite directions with the same set of pulsed drive fields and are used to build closed loop paths with parallel sides. Special cornering elements couple parallel channels to form rectangular loops.