Abstract: A computer system and method for cataloging objects, such as requests to purchase an item having a certain configuration, associated with a plurality of attributes describing that object. These attributes are stored in an aggregation component, which is linked to a set of permutation arrays. Each of the permutation arrays indicates an allowable ordering of the plurality of attributes. This object can then be matched with a second object, such as an offer to fill the purchase request, by comparing a plurality of attributes associated with the second object to the attributes describing the first object. Improved searching is effectuated by enabling the matching of objects to be based on the acceptable orderings dictated by the permutation arrays.

Abstract: Apparatus for selectively reading or writing data on a magnetic data stripe on a data card which is thin and flexible and for selectively returning or capturing the card. The apparatus includes a card guide arrangement comprising a cylindrical card guide path section, an entrance card path section with an entrance slit for admitting the data card, and an exit path section with an exit slit for discharging the data card for capture. A drive arrangement drives the data card through the entrance slit, throughout the cylindrical card guide path section, and through the exit slit. A transducer with a read head and write head is mounted relative to the cylindrical card guide path section. A position tracking arrangement determines the position of the data card within the cylindrical card guide and a card-in sensor senses the presence of a data card in the entrance path section. A microprocessor based control circuit is used to operate the system and control operational features.

Abstract: An actuator assembly for magnetic heads used with fixed magnetic discs. The heads are supported from one end of arms in a support assembly which is pivoted at the other end. Drive forces are applied directly to each of the arms through the support assembly at the center of percussion between the pivot and the heads. Drive forces are generated by a drive assembly including a coil and permanent magnets.

Abstract: An electronic tachometer, for use in a disk drive system, to sense velocity of an accessing head mechanism relative to data tracks being accessed, comprises a first feedback loop comprising a variable bandwidth differentiator for receiving a position signal and providing a velocity signal; and a second feedback loop including the differentiator and means for supplying a control voltage to said differentiator in response to a variable velocity signal provided by the differentiator.