Abstract: A method and system for synchronizing to an incoming Hsync signal, and for generating a phase locked clock signal in response thereto. The Hsync signal and an incoming clock are coupled to a sequence of modules. Each module includes a latch for sampling the incoming clock on a transition of the Hsync signal, whose output is combined (using an XOR gate) with the Hsync signal. Each module includes a time delay for generating a delayed clock signal, incrementally delayed from the previous module in the sequence, so that the clock signal for each module is phase-offset from all other modules. The latch outputs are summed using a resistor network, to produce a triangle-shaped waveform which is phase locked to the Hsync signal and which is frequency locked to the incoming clock. The triangle-shaped waveform is compared with a constant voltage to produce a square wave.

Abstract: Presentation of digital video and audio data in a computer system. Am application program may call upon a driver program to manipulate streams of video and audio data, including commands to present the video or audio to an operator, retrieve status information about the presentation, simultaneously present graphics with video data, halt or pause presentations, allocate or release resources for presentation, and group multiple streams for synchrony. The driver program may operate upon the grouped streams in synchrony in response to unified commands from the application program. An interface to the driver program may comprise a interrupt instruction invoked with a designated interrupt and a designated set of commands: initialization; open and close; play, pause, stop, seek, and step; group; set and get; installation; and termination.

Abstract: Apparatus and a method is disclosed for mixing animation sequences with computer graphics information for presentation on a computer display screen. The animation sequences may be stored in compressed format in a standard storage medium. An animation sequence generator retrieves these compressed animation sequences, decompresses them into pixel information, and sends them to a single line store for synchronization with the computer graphics pixel information. Pixels from the animation sequences and from the computer graphics generator are mixed, windowed and overlaid in a digital mixer. The output of the digital mixer is sent to a visual display system such as a video digital-to-analog converter driving a computer display monitor.

Abstract: Disclosed are a system and a method useful in fields such as architecture, space planning, interior design and corporate facility management, for efficiently designing and allocating space to the various subdivisions of an organization. Manipulation of colors is used in addition to numerical values to allow the user to determine at a glance the relative priorities of various departments and the affinities between pairs of departments at various stages of the space allocation process, and thereby speed the process and reduce the chance for errors.