Abstract: Disclosed is a method and device adapter for managing devices in a data processing system that includes a plurality of device adapters connected for independent communication with at least one shared device (e.g. disk data storage device). The method comprises the steps of: issuing a command from a first of the plurality of adapters to the at least one shared device; setting, in the first adapter, first and second timeouts associated with the command; on expiration of the first timeout value, issuing a message from said first adapter to other(s) of the plurality of adapters to request the other adapter(s) to notify the first adapter of any work requested of the shared device by the other adapter(s); and on expiration of the second timeout value, initiating a recovery operation in the data processing system.

Abstract: A data processing system comprises means for identifying and replacing instructions to jump to functions having known prolog instructions with modified jump instructions, means for storing the known prolog instructions, and means for retrieving the known prolog instructions when such modified instructions are found and for supplying the known prolog instructions for processing. A compiler or preprocessor is arranged to detect and modify the jump instructions. A logic module is arranged to intercept the modified instructions, retrieve from its storage the prolog instructions, and supply the prolog instructions for processing. The compiler or preprocessor is further arranged to detect and modify the first instruction of known epilog code. A logic module is arranged to intercept the modified instruction, and to retrieve and supply for processing the epilog instructions.

Abstract: There is described a personal conferencing method and system for a client (32)/server (30) environment. The server (30) stores conference model data (60) such as a shared chalkboard or a molecular model and each client has a copy of the conference model data (61). When one of said clients (32A, 32B, 32C) edits the model (61) it creates an instruction (64A) for operating on the model and sends the instruction (64A) to the server (30). The server (30) operates (62) on its conference model data (60) on receipt of the instruction (64A) and resends the instruction (64B) to each of the clients (32A, 32B, 32C) and each client (32A, 32B, 32C) performs the same operation (63) on their respective copies of the conference data model (61). Whereby after a plurality of different operating instructions (64B) from different clients (32A, 32B, 32C) the respective copies of the conference model data (60) are equivalent.

Abstract: A system and method are provided for processing data representing stored images so that a set of such stored images can be represented simultaneously on an output medium having a specified output area in such a way that more effective use of the output area is made than previously possible with prior art techniques. Typically the set of stored images to be represented will result from an image database search and the output area will be a display screen of a monitor.

Abstract: A local computer 132 is connected to a remote computer 136 over a network for collaborative processing, whereby changes to the screen of the local computer are to be reflected on the screen of the remote computer. A hook routine 110 is used to intercept requests to update the screen of the local computer, and the area of the screen to be updated is determined from the request. Another routine then obtains the bit map for the area of the screen which has been updated, and only this bit map is transmitted to the remote computer, rather than one corresponding to the whole screen.

Abstract: A computer workstation runs an application 12 which generates data for transmission over a network. The workstation includes a communications subsystem 14 which is responsible for actually sending data generated by the application onto the network. The application therefore passes data 22 for sending to the communications subsystem, along with the identification 24 of the channel over which that data is to be sent, and compression information 26. In a first embodiment the communications subsystem contains a variety of compression routines 40, and the compression information indicates which of these routines is most appropriate for the data in question. In a second embodiment, the compression information is a call-back function 92, whereby the communications subsystem can call back to the application program to perform the compression itself.