Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Video memory system










Image Number 6 for United States Patent #4644495.

An improved video memory system includes a program memory, a display data memory, and a plurality of data fetchers. The data fetchers are used to indirectly address the display data in the display data memory. The data fetchers are programmed during vertical blanking so that selected display data is fetched at selected vertical display positions. During each scan line each data fetcher is "read" by: (1) decrementing a counter in the data fetcher; (2) comparing the counter value against preselected top and bottom values; and (3) using the counter value to indirectly address display data that is to be displayed on the current scan line if the counter value is between the top and bottom values. This relieves the host computer of having to keep track of the current vertical display position, thereby freeing it to use the saved computer cycles to produce more interesting viedo games with more complex display graphics. In addition there are provided data fetchers that can be programmed to periodically issue signals usable either for drawing a line with a predefined slope or modulating the amplitude of a sound generator.








 
 
  Recently Added Patents
Reconfigurable barrel shifter and rotator
Substituted di-arylhydantoin and di-arylthiohydantoin compounds and methods of use thereof
Conductive polymer and a solid electrolytic capacitor using the same as a solid electrolyte
Passive millimeter wave differential interference contrast polarimetry
Fast base station switching method and system, and hierarchical zone-based fast handoff approach
Stable aqueous composite compositions
Method to dynamically tune precision resistance
  Randomly Featured Patents
Impact and energy absorbing product for floors, walls, and other flat surfaces
Breakaway/swingaway truck mirror
Cover for electric foot massager
Apparatus for reducing erosion due to cavitation in ink jet printers
Derivatives of aryl ketones and p-dialkyl-aminoarylaldehydes as visible sensitizers of photopolymerizable compositions
Engine enhancer
Method for gun barrel manufacture using tailored autofrettage mandrels
Optical disk for high resolution and general video recording, optical disk reproduction apparatus, optical disk recording apparatus, and reproduction control information generation apparatus
Tissue tonometer device for use in measuring gas in body tissue
Methods and systems for providing secure access to a hosted service via a client application