Abstract: A system for switching data between the terminals of a communication network includes a memory and management device storing a model of the network and performing management of this model, the model being constituted by a set of objects which are representative of the elements of the network at a given moment and which have properties defining the characteristics of these elements at that moment, a device manipulating the objects adapted to create new objects, modify existing objects, or delete existing objects from the model, and an interface between the memory and management device and the hardware elements of the network.

Abstract: A video display terminal permitting substantially continuous scrolling of the display. Each character row of the display is stored in the display memory in a memory segment which also stores one or more parameter bytes associated with the character row. A first parameter byte portion indicates the number of the scan line on which the display of that character row is to commence during the current frame. A second parameter byte portion indicates the number of scan lines of that character row which are to be displayed during that frame. A memory address within the parameter bytes indicates the address of the memory segment storing the next character row to be displayed. This memory address is applied directly to the DMA controller.