In late '80 Apple, exactly meanwhile Apple was explain to the whole planet what the mouse was, inside the ATG (the reserch dep of Apple), someone was working...
C. Ferrán-Urdaneta. SIGCPR '99: Proceedings of the 1999 ACM SIGCPR conference on Computer personnel research, стр. 128--134. New York, NY, USA, ACM Press, (1999)