Patents by Inventor Phillip R. Barrett

Phillip R. Barrett 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).

  • Method of transferring control in a multitasking computer system
    Patent number: 4974159
    Abstract: An improved method and system for transferring control in a multitasking computer system is provided. In preferred embodiments for use with 80386 machines, the virtual machine monitor (VMM) writes a virtual machine break point (VMBP) instruction into the executable code of selected DOS routines to cause the DOS routines to transfer control to the VMM. By selecting systems calls of indefinite duration for the application of this method, system performance can be improved. In this preferred embodiment for 80386 machines, 8086 programs designed to run under DOS can be more efficiently executed in a multitasking environment.
    Type: Grant
    Filed: September 13, 1988
    Date of Patent: November 27, 1990
    Assignee: Microsoft Corporation
    Inventors: Richard R. Hargrove, Phillip R. Barrett, Ralph A. Lipe, Aaron R. Reynolds, Marc D. Wilson