Transmission of teletext data - having data organised as main page data ans as expansion page data

摘要

A world teletext transmission system has data periodic transmitted along with a television signal. At the receiver end the teletext data is separated from the television signals and is then entered in a collected form into a buffer memory. The teletext data can be subdivided into base data that is arranged in page format. Other information can be organised as expansion data on additional pages. ADVANTAGE - Provides optimum use of page memory.