Abstract: In a Teletext transmission system, data is transmitted in digital form during lines in the field blanking period of a composite video signal of a television transmission. On reception, the information is decoded and utilized to provide a display comprising a page having a predetermined number of rows of information in alphanumeric or graphics form. The data is received in blocks comprising information digits and each block has an associated group of address digits so that each block can be directed to an appropriate storage location in a first store, regardless of the order in which the data blocks are transmitted. The contents of the first store can then be transferred in address order into a larger capacity serial store ready for use in generating the display. Thus it is possible for a number of pages of information data to be correctly assembled in serial row order, ready for display generation, in a manner accommodating non-transmitted blank rows.

Abstract: An analog signal storage system wherein degenerate analog signal storage devices may be used for relatively long time analog data storage. A recirculating charge transfer device shift register is used to store the analog data and a variable gain amplifier is included in a recirculation path between the shift register output and input. The gain of this amplifier is periodically adjusted so as to maintain the overall loop gain of the system at unity. The gain control signal is produced by comparing the amplitudes of a reference signal pulse before and after propagation through the shift register. Based on this comparison, a control signal is generated and applied to adjust the gain of the variable gain amplifier in a sense tending to compensate for signal loss due to propagation through the shift register. The output of the shift register may be strobed to read out analog signal data for external utilization at a lower rate than the propagation rate through the shift register.