Abstract: A communication protocol includes a hierarchical arrangement of time slots within a communication channel for transmission and reception of isochronous data (e.g., video, audio, etc.) between components of a computer network. One of the time slots may include a window for transmission of keyboard and/or cursor control data from a client unit to a server, for example as a series of past and present keyboard and/or cursor control entries, with these entries being accompanied by a counter value indicative of the number of new entries since a previous transmission. Audio rate control information may also be transmitted from the client unit to the server during the reverse time slot and may be used by the server to determine the amount of audio information to be transmitted to the client unit in a subsequent forward time slot transmission period. The audio rate control information is determined according to the amount of stored audio information at the client unit.

Abstract: In some embodiments, a storage medium comprises application software that performs one or more operations and that directly facilitates the conversion of a virtual memory address to a physical memory address. The application software comprises instructions that initialize an application data structure (e.g., an object or array) usable by the application software to facilitate the conversion of memory addresses and also comprises instructions that store pointers to the virtual memory addresses to be converted. In other embodiments, a system comprising a secure and non-secure memory subsystem is disclosed. Before execution of an application stored in the secure sub-system, a list of pointers to parameters contained in virtual memory is created. The virtual memory addresses referenced by the pointers in the list are converted to pointers to physical memory addresses before execution of the application.

Abstract: A printer featuring an optical data link between the printer's controller and its reciprocal, carriage-mounted printhead is described. Print data are conveyed from the controller to the printhead via a fixed point on the edge of the carriage and status data may be conveyed in the reverse direction. Power is supplied to the printhead via dual parallel rails on which the carriage is supported for reciprocation by the chassis-mounted carriage drive motor. Preferably, the optical medium is infrared light, and uses conventional driver/receiver devices.