Abstract: A keyboard/video/mouse (KVM) switching protocol is disclosed in which KVM information is applied to a network of workstations. At least one data converter communicates on the workstation network and retrieves KVM information from the workstation network that is addressed to a server assigned to the converter. The converter places the KVM information in a format suitable to the assigned server and applies the converted KVM information to the appropriate standard device ports of the server. The system provides motherboard access to the servers that is characteristics of KVM switches but provides essentially unlimited scalability not known in traditional KVM switches.

Abstract: A video graphics system wherein a large quantity of video data is independently and selectively made available to plural video display devices. The large quantity of video data can be contributed to by plural sources of video data of differing formats. Further, the display devices can also be of varying types, each requiring a different input data format. A multi-sourced video distribution element, also referred to as a hub, serves as an interface between one or more sources of video display data and one or more video display devices. One source of data can be identified as a base image, and other sources of data can be utilized for overlay images integrated into the base image. The base image and any integrated overlay images are provided on a pixel bus internal to the hub. The hub can then be configured as an interface to one or more types of video display devices and/or to another hub.

Abstract: A video distribution hub and display method are disclosed which is capable of driving a plurality of video display monitors as a virtual monitor or monitors. The video distribution hub receives a video signal from a single head graphics card or a suitable video source which signal embodies data within a video buffer on the graphics card or at the video source. The hub processes the received video signal and stores selected data segments corresponding to selected portions of the video buffer in a plurality of frame buffers within the distribution hub. The data stored within the plurality of frame buffers is employed to drive respective video displays, such as flat panel displays or conventional CRT displays. The hub accommodates displays of different resolution. Additionally, the hub accommodates displays having either a portrait or landscape orientation.

Abstract: A method for performing address and data transfers among a plurality of different units of a data processing system having a system bus which includes an address bus and a data bus. The system uses arbitration phase, address transfer phase, and data transfer phase operations which require the use of unique handshake signals at each phase so as to permit address and data transfers to occur on a suitable priority basis with respect to different ones of such units in a pipelined manner using non-multiplexed, asynchronous operations.

Abstract: A bus arbitration algorithm using round robin and variable packet counts. In addition, each node is assigned a maximum packet size which can be adjusted by the operating system. The round robin determines which node will be granted the bus based on priority on a serial wrap-around list. The packet count is one factor in determining how long the node granted the bus may use it. The maximum packet size is a second factor in determining the permitted duration on the bus.