Patents by Inventor William C. Ellsworth

William C. Ellsworth has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4301516
    Abstract: A magnetic bubble domain memory device is provided that includes a magnetic domain data chip having a major-minor loop organization with on-chip firmware providing redundancy information enabling the use of the chip even though one or more defective minor loops may be present thereon. One of the pages is written in the minor loop, where a page is defined as a common bit position in each of the plurality of minor loops, with a series of magnetic domains having an odd total number. The next succeeding page in the minor loops contains a series of magnetic domains and voids which are representative of the loop numbers of defective minor loops on the chip with the remaining pages in the minor loops having an even number of magnetic domains contained in each of the pages. Collectively, the pages containing the odd and even number of magnetic domains together with the page containing the map of the defective minor loops comprise the on-chip firmware providing redundancy information.
    Type: Grant
    Filed: December 12, 1979
    Date of Patent: November 17, 1981
    Assignee: NCR Corporation
    Inventor: William C. Ellsworth