A PC-controlled multiple window display card for TV

The development of a personal computer (PC)-controlled multiple window display card for television is described. A digital encoder card for converting the red, green and blue (RGB) signals from the PC to a composite video signal (CVBS) is designed and developed. This digital encoder card accepts the RGB analog signals from the computer VGA display adaptor card and converts them into a PAL or NTSC format composite video signal. A chroma keying circuitry, to enable an additional video signal to be displayed with the encoded CVBS signal on a television screen in a picture-in-picture format is also included. >