The document traces the evolution of touchscreen technology from 1972 to 2012. It describes several important early touchscreen devices including the PLATO IV (1972), the first touchscreen computer; the HP-150 (1983), the first commercial touchscreen computer; and the Home Manager (1985), the first touchscreen home automation system. It then discusses influential early mobile devices such as the GRiDPAD (1989), the Simon (1992), the first smartphone, and the Pilot (1996). Modern touchscreen milestones covered include the iPhone (2007), which popularized the technology; Microsoft Surface (2007), an early multi-touch table; the iPad (2010-2012), which launched the tablet era. The document concludes that touch