Abstract: A method of improving run length video encoding commands is described in which all compression commands that require a current pixel value to be compared to a previously sent pixel value to determine whether compression can take place in a longer run is adjusted to relieve stringent match conditions. Instead of requiring an exact match, the compression engine subtracts one pixel value from another, and compares the absolute value of the result to a threshold value. In this way, run lengths can be lengthened for purposes of compression and compression efficiency can be increased.

Abstract: A two-stage pixel skew compensation circuit for use with digital display monitors. The first stage of the compensation circuit aligns the edges of the pixels received on the color component signal lines of an analog video signal. The second stage of the de-skew compensation circuit realigns the pixels themselves so that no skew exists between the digitized video color components. The digitized video signals drive a digital video monitor.

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 method of improving run length video encoding commands is described in which all compression commands that require a current pixel value to be compared to a previously sent pixel value to determine whether compression can take place in a longer run is adjusted to relieve stringent match conditions. Instead of requiring an exact match, the compression engine subtracts one pixel value from another, and compares the absolute value of the result to a threshold value. In this way, run lengths can be lengthened for purposes of compression and compression efficiency can be increased.

Abstract: A video compression system for compressing a stream of digital video data is disclosed. Known run-length encoding is applied whenever possible to the digital video data stream. When a run is not identified, the encoder determines whether a consecutive series of pixels are identified from only two different colors, and if so creates a make-series command to create bytes with bits encoded as a stream of binary values corresponding to the two pixel colors as they occur in the consecutive series. The make series command continues for as many bytes as the consecutive series of bits will fill, except that, when a make series command applies again to a byte of make-series bits, the make series command is preempted by the applicable run length encoding.

Abstract: A video compression system for compressing a stream of digital video data is disclosed. Known run-length encoding is applied whenever possible to the digital video data stream. When a run is not identified, the encoder determines whether a consecutive series of pixels are identified from only two different colors, and if so creates a make-series command to create bytes with bits encoded as a stream of binary values corresponding to the two pixel colors as they occur in the consecutive series. The make series command continues for as many bytes as the consecutive series of bits will fill, except that, when a make series command applies again to a byte of make-series bits, the make series command is preempted by the applicable run length encoding.

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.