Abstract: A CATV center facility transmits, together with the television signals of a plurality of programs, display control data indicating program names and selection numbers of the respective programs and channel data indicating the numbers of channels on which the respective programs are being broadcast or to be broadcast. A terminal apparatus detects the program names, selection numbers and channel numbers from the display control data and the channel data, and makes a TV receiver display the detected program names and selection numbers in an associated manner. While looking at a picture thus displayed, a user selects a desired program by pushing a corresponding numeral button of a remote controller or a keyboard. In response to the program selection by the user, the terminal apparatus is tuned to the channel of the selected program.

Abstract: A method of scrambling a television signal and a method of and apparatus for descrambling a television signal is provided. An audio signal is used on which a key signal containing compression information and information concerning the position of a vertical blanking interval is superimposed on a portion of the audio signal corresponding to a horizontal blanking interval. In addition, a pseudo-key signal is superimposed on the audio signal at a portion which corresponds to a vertical blanking interval, so that the vertical blanking interval cannot be detected through the detection of the audio signal. As a result, an expansion signal for expanding the signal in the horizontal blanking interval and vertical blanking interval compressed by scrambling cannot be formed in its normal position. Thus, unauthorized access is difficult.

Abstract: An extension control signal for a vertical blanking interval (VBI) rises at a timing delayed from the last key signal before the VBI by 64 .mu.sec plus the time difference between the key signal and horizontal synchronizing signal section, and falls at a timing delayed from the first key signal after lack of the key signal detection by an extension period of the horizontal synchronizing signal section plus the above time difference.