Abstract: Two computer workstations are connected together by a communications link 300. One workstation (the local workstation) 100 includes a window 610 which is used to display a copy of what is currently being displayed on the screen of the other (remote) workstation 200. Each time an update is made to the screen of the remote workstation, it must be transmitted to the local workstation. A bounding rectangle 920 for the area of the screen changed by the update is determined. If the bounding rectangle is greater than a predetermined size, then a first packet is transmitted from the remote workstation to the local workstation, prior to the transmission of the actual update itself. This first packet indicates the bounding rectangle for the updated area of screen. The local workstation responds to the first packet by greying (shading) the corresponding region 925 of the window which contains the copy of the remote screen, thereby indicating to a user of the local screen that an update is imminent.

Abstract: In system and method for data compression and decompression, runs of the same bit value are identified within the data to be compressed and decompressed into a series of groups of bits wherein the number of bits in each group progressively increases as compared to the preceding groups until all of the bits of the run can be represented.