PC Technology Guide
Pc Tech Guide: Graphics Cards
Detailed explanation of the graphic card. A wide variety of topics are discussed. Sections to check out include: resolution, color depth, dithering, components, graphics processor, video memory, and RAMDAC.
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Pc Guide: Video Cards
This site from the PC Guide provides a detailed explanation of what a video card is and its purpose. This site is a thorough reference to learn more about video cards and their capabilities.