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:
Mar. 09, 1993
Filed:
May. 18, 1990
Richard Bealkowski, Delray Beach, FL (US);
Richard A Dayan, Boca Raton, FL (US);
David J Doria, Boca Raton, FL (US);
Scott G Kinnear, Boca Raton, FL (US);
Jeffrey I Krantz, Boca Raton, FL (US);
Robert B Liverman, Raleigh, NC (US);
Guy G Sotomayor, West Palm Beach, FL (US);
Donald D Williams, Boca Raton, FL (US);
Gary A Vaiskauckas, Boca Raton, FL (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
A computer system and method for operating a computer system capable of running in mutually incompatible real and protected addressing modes, in which programs written for one mode can be run in the other mode without modification. The BIOS assembles two different common data areas for the two modes, each inclusive of device block pointers, function transfer table pointers, data pointers, and function pointers. The common data area for the real mode is assembled first. To assembly the pointers for the protected mode common data area, the offset values from the real mode area ae copied directly, and then selector values are inserted whose physical addresses correspond to the segments of the corresponding pointers in the real mode area. The selector values are derived from a segment descriptor table.