I recently learned that German company Telefunken arguably invented the computer mouse. They offered a “Rollkugelsteuerung” (“rolling ball control”) for one of their mainframes in 1968, months before Douglas Engelbart’s “mother of all demos”. Telefunken’s mouse was also more advanced than Engelbart’s mouse as it used a ball instead of two wheels. (Photo credit:
Marcin Wichary, CC-BY 2.0,
https://www.flickr.com/photos/8399025@N07/2322838281 and
https://www.flickr.com/photos/mwichary/2322836557/)
