On 27th April 1981, Xerox PARC introduced a computer mouse that has a single ball. The device was created by Bill English, the same engineer who had built the prototype of the first computer mouse invented by Douglas Engelbart at SRI.
Coincidentally, on the same day in 1968, Douglas Engelbart had demonstrated his invention – the computer mouse.
Years later, the design was improved upon by Jean-Daniel Nicoud and André Guignard who, in addition to the single ball, added two buttons to the mouse. The device was then commercialised by Logitech – the fist company to sell the computer mouse.
