04994912 is referenced by 111 patents and cites 24 patents.

A method and apparatus for synchronizing two independent rasters, such that a standard TV video and a high resolution computer generated graphics video may each be displayed on a high resolution graphics monitor. This is accomplished utilizing dual frame buffers. A TV frame buffer, comprises a dual port VRAM, with the serial and random ports operating asynchronously. The primary port receives incoming TV video synchronously as it comes in, and the secondary port reads the TV video out synchronously with the high resolution graphics monitor. A high resolution frame buffer in a computer is utilized to store high resolution graphics which is read out synchronously with the high resolution graphics monitor. A switching mechanism selects which of the TV video and the high resolution graphics video is to be displayed at a given time. The TV frame buffer includes an on screen and off screen portion. The computer provides computer data, including high resolution graphics data and audio data to the TV frame buffer, with the graphics data being stored in the on screen portion and the audio data being stored in the off screen portion. The audio data is read out to an audio circuit for replay. The graphics data is combined with the TV video for purposes of windowing.

Title
Audio video interactive display
Application Number
7/314623
Publication Number
4994912
Application Date
February 23, 1989
Publication Date
February 19, 1991
Inventor
Alan W Peevers
Peekskill
NY, US
Leon Lumelsky
Stamford
CT, US
Agent
Jack M Arnold
Assignee
International Business Machines Corporation
NY, US
IPC
H04N 7/01
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