When I entered graduate school in 1986, I remember reading about the idea of using a pen as an input device to a computer. Little did I know that the idea had been around for long time, from the very early days of modern computing. Visionaries like Vannevar Bush in his famous 1945 article “As We May Think” and Ivan Sutherland’s SketchPad system from the early 1960s saw the potential of adapting the flexibility of writing and drawing on paper to computers.
Gord Kurtenbach. (2010). Pen-Based Computing XRDS: Crossroads, The ACM Magazine for Students. June 2010, 16 (No. 4). pp. 14 - 20.