Abstract: A television receiver system having secondary picture display capability (such as PIP or POP) includes two tuners and signal processing arrangements, and circuitry for receiving a transmitted channel guide. In response to a "BROWSE" command, the receiver maintains the currently-tuned first channel as the source for the main picture, displays text related to a television show on a second channel, activates the secondary picture display circuitry, and tunes the second tuner to the second channel. In this way, the viewer can simultaneously get the benefit of both a text description of the television show on the second channel and view a secondary image of the television show on the second channel, without tuning away from the first channel supplying the main picture.

Abstract: The digitized video image data stored in a video RAM in a pix-in-pix television receiver is modified by the addition of digital data from an external computer via a computer interface circuit under control of the pix-in-pix controller. The computer interface circuit is coupled to the internal controller of the television receiver via an external input terminal. The additional digital data received from the external computer may be representative of either text or graphics to be merged into the stored video image.

Abstract: A video input signal is stored in a memory and read twice during a line-interval to provide a processed video output signal having a doubled line rate for display on a display device having a doubled horizontal sweep rate thereby providing a progressively scanned image having reduced visibility of line structure. The last address written in memory is used to control the starting time of the second memory read operation. This reduces the tendency of visible artifacts to occur in cases where the video input signal is "non-standard" in the sense that the ratio of the color subcarrier frequency with respect to the line rate is such that the number of color subcarrier cycles per line may be subject to variation.