Multimedia, or mixed-media, systems offer presentations that integrate effects existing in a variety of formats, including text, graphics, animation, audio, and video. Such presentations first became commercially available in very primitive form in the early 1980s, as a result of advances that have been made in digital compression technology-- particularly the difficult area of image compression. Multimedia online services are obtainable through telephone/computer or television links, multimedia hardware and software exist for personal comput ....