Abstract: A computer system has physical pages of memory subject to access by input/output (“I/O”) devices, and a certain table with entries associating the physical pages with the I/O devices. Responsive to a request for data be moved from a first physical page to a second physical page, an entry is selected for the first physical page in the table. The selected entry indicates an association of the first physical page and one of the I/O devices. Arbitration is temporarily disabled for the selected I/O device so that I/O operations for the I/O device are temporarily disabled. Once arbitration is disabled for the device the data is moved from the first physical page to a second one of the physical pages and the entry is updated in the table to reflect a new association between the I/O device and the second physical page.

Abstract: A computer network including a server for receiving and sharing a presentation of foils with a plurality of user clients under the control of a presenter. Each user client has a terminal for displaying the foils; a browser for interacting with the server and a cache for storing the foils. Each foil is contained in a data structure, typically a HyperText Markup Language (HTML) page including a time line of past foils which enables a user through an interface to view each foil, scan over the time line to view any past foil and quickly reset the presentation to the current foil viewed on the network by the other user clients. Each user or viewer in scanning or browsing through the past foils does not interfere with other user clients viewing the presentation or to the presenter.