Issue No.06 - June (1970 vol.19)
An inexpensive computer graphical input device giving Cartesian coordinates with better than 1-mm resolution is described. The technique works equally well for two-or three-dimensional input variants of the device.
Digital stylus, graphical input, sonic pen, three-dimensional input, two-dimensional input.
A.E. Brenner, P. de Bruyne, "A Sonic Pen: A Digital Stylus System", IEEE Transactions on Computers, vol.19, no. 6, pp. 546-548, June 1970, doi:10.1109/T-C.1970.222973