Rapid access teletext decoder arrangement

Abstract

A teletext decoder includes a background or buffer memory operating as a first-in, first-out (FIFO) memory. The buffer memory is used for storing a large number of teletext pages. A given video line that contains teletext information is identified as such by the detection of part of a clock run-in sequence followed by the framing code. The video line is then stored in the background memory. After a user page request occurs, the background memory is read-out by a data processor operating in a full channel mode of operation for obtaining the information of the requested page. As long as the read-out operation has not been terminated, incoming teletext data is stored in the background memory. This enables teletext data received prior to termination of the read-out operation to be read out and processed by the data processor.