Patents by Inventor Fred Parnell

Fred Parnell 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).

  • Hot plugging of an adapter card
    Patent number: 5680288
    Abstract: A circuit senses an insertion of an adapter card into a connector coupled to a processor by an MCA bus and signals control logic, which forces all other adapter cards coupled to the MCA bus off of the bus with a preempt signal, driving the bus into an arbitration mode. This may be done while the system is powered. An analog switch divides the preempt signal into one that goes to the adapter cards and a second one that is sent to the processor so that it can perform memory refresh cycles.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: October 21, 1997
    Assignee: International Business Machines Corporation
    Inventors: John J. Carey, Fred Parnell, Jeffrey Buchanan Williams