Patents by Inventor Douglas Hilgendorf

Douglas Hilgendorf 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).

  • Memory integrity checking system for a gaming device
    Patent number: 4727544
    Abstract: A system for continuously checking the integrity of the memories of a computer controlled gaming device. The gaming device includes a plurality of EPROMs for storing software and fixed data according to which the gaming device operates. A checksum algorithm stored in one of the EPROMs is periodically implemented throughout the operation of the gaming device to calculate individual checksums for each EPROM. The checksum calculated for an EPROM is compared to a checksum value stored for that EPROM to determine whether changes in the contents of the memory have been made.
    Type: Grant
    Filed: June 5, 1986
    Date of Patent: February 23, 1988
    Assignee: Bally Manufacturing Corporation
    Inventors: Norman Brunner, Phillip Pajak, Douglas Hilgendorf