Abstract: An electronic information display system which is organized as a reference information display system. The system comprises a reference source in the form of a compact disc CD ROM, which constitutes a mass read-only memory for the system. The disc contains text, graphics and/or sound data portions for a plurality of items of information. The disc also contains a list of these items together with addresses for their respective data portions. The system is processor-controlled such that the list and addresses are read from the disc into a programme memory. Using scrolling and/or selection techniques, the list can then be displayed a part at a time until a required item is found. Selection of this item will result in its data portions being transferred from the CD ROM to the programme memory where they can be accessed for use (i.e. visual or audible).

Abstract: An information display system which can produce an information display (e.g. on a television monitor) from any one of a plurality of different information sources. The information sources are associated with different facilities such as teletext and viewdata. In order to obtain information from a particular information source, the associated facility option is selected from the available facility options by selecting from the television screen "nested" areas which pertain to one or more facility options. The selection can be effected using a touch-sensitive screen which overlies the television screen. The selection process may comprise the display of a number of successive display frames containing "nested" areas. The selection of an area in one frame produces a fresh display frame which redefines areas which are nested within the selected area.

Abstract: A video display system includes a television monitor 1, a display generator 2, a display memory 3, a processor 4, and a main memory 13. The main memory 13 stores pages of text and pictures which can be selected for display. When a page is selected, the processor 4 controls its transfer from the main memory to the display memory where it is accessed by the display generator to produce the R, G, B display signals. The main memory 3 includes an index store 18 which contains indexing information which can be displayed in the form of index pages containing miniature aide memoire versions of the stored pages. In the aide memoire version of a text page, single dots represent respective characters of the text page. In the aide memoire version of a picture page, single dots represent respective discrete areas of the picture page. In the latter case, each dot has a color which is the average color of the area concerned.