Citrix Systems, Inc.

International Business Machines Corporation

Jeffrey Isaac Krantz

Marc A Bloomfield

Richard Alan Dayan

Richard Bealkowski

Donald D Williams

Guy G Sotomayor, Jr

Scott G Kinnear

Gary A Vaiskauckas

David Joseph Doria

Thanh Luu

Robert B Liverman

A method for dynamically caching data objects in a logical cache memory begins by organizing the logical cache memory into a set of maximally equally-sized, contiguous pages that begin at a logical cache base address. Any one of the maximal size logical cache pages may be dynamically subdivided into a set of smaller pages of equal size. The smaller size pages cache data objects having a smaller size than the maximum possible data object size. Each subdivided page stores only those smaller size data objects. The logical address for a page is mapped to at least a maximal size page index identifying the position of the maximal size logical page in the cache and, if the page is a smaller size page, the page location is also mapped to a smaller size page index which identifies a particular one of the smaller size pages located within a maximal size page. Pages are dynamically reconfigured based on a least-recently-used policy. A maximal size page may be reconfigured to provide for storage of multiple smaller sized pages and a set of smaller sized pages may be reconfigured to provide storage for a maximal size page. In one aspect, maximally sized pages may be chained together to provide for storage of data objects which exceed the size of the pages. Chained pages may be contiguous or non-contiguous.

Method for dynamically and efficiently caching objects received from an

A lossless bandwidth compression method for use in a distributed processor system for communicating graphical text data from a remote application server to a user workstation over a low bandwidth transport mechanism enables the workstation display to support the illusion that the application program is running locally rather than at the remote application server. At the application server, the graphical text data is represented by a string of glyphs, each glyph being a bit mask representing the foreground/background state of the graphical text data pixels. Each unique glyph is encoded by assigning a unique identification code (IDC). Each IDC is compared with the previous IDCs in the string and, if a match is found, the IDC is transmitted to the workstation. If a match with a prior IDC is not found, the IDC and the corresponding glyph pattern are transmitted to the workstation. At the workstation, the IDCs are queued in the order received while the glyph patterns are cached using the corresponding IDCs as addresses. The string of glyphs is reconstructed by using the queued IDCs in their natural order for accessing the cached glyph patterns as required to reproduce the original string of glyphs.

Method for lossless bandwidth compression of a series of glyphs

Method for dynamically and efficiently caching objects by subdividing

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.

Computer system having mode independent addressing

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 operating system using 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 assemble the pointers for the protected mode common data area, the offset values from the real mode area are 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.

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Boca Raton, FL, United States of America

Jeffrey Isaac Krantz