Abstract: As advances continue to be made in the area of semiconductor memory devices, high capacity and low cost will be increasingly important. In particular, it will be necessary to create memory devices for which the testing of the device must be minimized in order to minimize costs. Current memory manufacturing costs are significant and will grow as the capacity of the devices grows—the higher the memory's capacity, the more storage locations that must be tested, and the longer the testing operation will take. The cost of the testing can be calculated by dividing the amortized cost of the test equipment by the number of devices tested. As memory devices enter the Gigabyte range and larger, the number of devices that can be tested by a given piece of test equipment will go down. As a result, the cost per unit attributable to testing will rise.

Abstract: The present invention is a means for constructing a high density memory device for very low cost by fabricating the device three dimensionally in layers. To keep points of failure low, address decoding circuits are included within each layer so that, in addition to power and data lines, only the address signal lines need be interconnected between the layers—not the exponentially greater number of decoded rows and columns. Furthermore, to keep the testing of the device low in cost, a row and column interconnect means is disclosed for testing the any two-dimensional array within the three-dimensional array with a single continuity and short-circuit test.

Abstract: As advances continue to be made in the area of high density data storage devices, the storage of such data as music (as is presently stored on audio CD-ROM's), books on tape, videos, movies and the like will become more common. However, when this type of information is stored digitally, the risk of data piracy will increase. What is needed is an integrated copy deterring mechanism for stored digitized information such as audio recordings and the like. The present invention is a digital data storage device which comprises one or more Digital to Analog Converters (DAC's). By incorporating Digital to Analog Converters on the chip or within the chip's packaging (a hybrid device), data being output could be made available in an analog form only (although some portion of the stored information could still be made available in a digital format). A device employing the analog output means disclosed could comprise read only data storage means or writable or one time programmable data storage means.

Abstract: A portable cooler comprising a cooling compartment having a pair of wheels coupled thereto at one end thereof and having a handle positioned on and coupled to one side of the cooling compartment opposite said wheels for pulling the portable cooler. The handle is angularly adjustable about an axle when the cooler is being pulled and is secured to the cooler when not in use. A pair of lifting handles are positioned on opposite sides of the cooler for lifting the cooler to and from a vehicle.