the original prestel system, designed for cost effectiveness and simplicity, employed a rudimentary graphic capability known as serial mosaics. through juxtaposition of the special mosaic characters, crude but recognizable graphic representations could be made on the screen. this graphic scheme had its limitations. to change colors between two mosaic graphic characters or between any two characters in general, a color change command was required. this command signal, however, physically occupied a blank space on the screen.the french sought to overcome this limitation when they joined the videotex world in the mid-1970s. they called their system antiope. while based on the same mosaic graphics that were employed by the british, antiope added a new feature, parallel attributes, or the ability to change the color from one cell to another without the need for a blank space.