Apple Computer, Inc. -- 1989
During the development of HyperCard 2.0 Bill was called in to consult on a number of problems, one of the most interesting of which was how to scroll large cards on small screens with greater ease and control than standard scrollbars would allow. His solution to this problem gained him a patent.
Briefly, a small, floating window represents the entire card in miniature. A small white rectangle in this window represents the position of the display window in which the card is being shown. By manipulating the small, white rectangle you can freely position the image of the card within the display window.