Video Display Controller

A video display controller, or VDC is an integrated circuit which is the main component in a video signal generator. Its mission is to generate the video signal to the TV or the monitor in a data processing system or in a game system. VDCs were common in the old home computers of the 1980s, but also in some early video game systems. Current computer systems instead use a graphics processor ( GPU) that can take on more functions and certain calculations for image preparation is performed independently. The actual image conversion happens in the RAMDAC.

The VDC was the main component of the video signal generator logic, but sometimes there are also other support chips such as RAM to hold the pixel data and ROM to store fonts. In text-only systems, the VDC takes over the task of generating the letters from the character values ​​in the main memory and the font. Some VDCs were able to do some tasks using shift registers and pallets independently. The graphics processor of the Nintendo Entertainment System was responsible, for example, the sprite on the screen. If no additional RAMDAC is present, the VDC generates the timing signals of the video signal, so the clock signals for the cathode ray of the screen.

  • Television Technology
  • Microcontroller
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