Patents by Inventor Duane Marcroft

Duane Marcroft 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).

  • Integrated modem which employs a host processor as its controller
    Patent number: 5170470
    Abstract: An embedded modem that does not require a dedicated controller and operates with existing computer to interpret new and redefined communications interrupt requests. In response to an interrupt request, the control of the processor is transferred from the communications software to a driver program stored in the main memory for the processor. Under the operation of the driver program, the processor interprets control characters and causes the appropriate commands to be carried out in the modem. Once these commands have been processed, the control of the processor reverts back to the communications program. The processor thereby functions as a virtual controller that is interpreted to be an external controller by the communications program.
    Type: Grant
    Filed: May 2, 1988
    Date of Patent: December 8, 1992
    Assignee: National Semiconductor Corp.
    Inventors: Andrew Pindar, Duane Marcroft, Andrew J. Nichols, III