A raster scan display system includes a plurality of storage maps. These maps are addressable in either of two modes. In the first mode each map contains bit mapped data and the maps are addressed together to provide color signals from which color video signals are derived. In the second mode, one map...http://www.google.com.au/patents/US4580135?utm_source=gb-gplus-sharePatent US4580135 - Raster scan display system
