The tablet computer and its associated operating system began with the development of pen computing.[12] Electrical devices with data input and output on a flat information display existed as early as 1888 with the telautograph,[13] which used a sheet of paper as display and a pen attached to electromechanical actuators. Throughout the 20th century devices with these characteristics have been imagined and created whether as blueprints, prototypes, or commercial products. In addition to many academic and research systems, several companies released commercial products in the 1980s