The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 24, 1990
Filed:
Dec. 08, 1987
Joseph H Binkley, Palo Alto, CA (US);
Perry A Caro, Palo Alto, CA (US);
John B Dillon, Palo Alto, CA (US);
Charles R Fay, Long Beach, CA (US);
Jonathan Gibbons, Mountain View, CA (US);
Hilary N Hooks, Newark, CA (US);
Abdo G Kadifa, Palo Alto, CA (US);
Jeffery W Lee, Palo Alto, CA (US);
William C Lynch, Palo Alto, CA (US);
Clayton W Mock, Redwood City, CA (US);
Everett T Neely, Montara, CA (US);
Michael L Tallan, Mountain View, CA (US);
Geoffrey O Thompson, Palo Alto, CA (US);
Gaya Vukkadala, Sunnyvale, CA (US);
John D Wick, Palo Alto, CA (US);
Donald R Woods, Los Altos, CA (US);
Xerox Corporation, Stamford, CT (US);
Abstract
An emulating data processor includes a host system and an emulating processor with outputs to and inputs from the host system. The emulating processor executes sequences of instructions executable by a PC being emulated, but a host processor independently executes sequences of its instructions which are different from PC instructions. Circuitry monitors the emulating processor outputs and provides information to the host system so that it can emulate the environment of the PC CPU, emulating both memory and I/O devices. The memory accesses of the emulating processor are mapped into the host system memory, so that the host processor is protected from defective PC software on the emulating processor. The display updates of the emulating processor are detected and provide information for the host processor in updating a part of its display which provides the information a PC display would provide simultaneously with the display characteristic of the host system. An input/output processor handles I/O operation requests of the emulating processor, using the host system I/O devices to emulate some of the PC I/O devices. The host system emulates the environment of the emulating processor while emulating the user interface of the PC.