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
Load balancing for parallel tasks
Flood protection apparatus and container data center including the same
Monitoring device for monitoring a display device
Method and system for triggering message waiting indicator delivery
Lens driving device
Interconnect, bus system with interconnect and bus system operating method
Compact ion accelerator source
  Randomly Featured Patents
Method of manufacturing a fuel tank from synthetic resin
Method for manufacturing semiconductor device
Method of transmitting and receiving signal indicative of remaining capacity of storage battery for propelling electric vehicle
Automated error checking system and method
Substituted 2,3-alkylene bis (oxy) benzamides and derivatives and method of preparation
Illuminated sparkling pumpkin
Vehicular headlamp
Combined wall switch and escutcheon therefor
Apparatus for repairing accident-damaged bodies in motor vehicles
Enhancement of return to independent living status with a growth hormone secretagogue