1973: Xerox Alto Computer
The revolutionary Xerox Alto computer was introduced internally at the Xerox Palo Alto Research Center (PARC) in 1973. This was the first manufactured machine to use a mouse, and the Ethernet protocol was established to network the machines within Xerox. The main processing unit, the size of a small refrigerator, was designed to sit under a desk or table, while the display, mouse, and keyboard sat on the tabletop. The display was shaped like a piece of letter-sized paper and in conjunction with the mouse employed a graphical user interface (GUI). This was perhaps the most farsighted feature of the machine, as it took another 20 years for GUI's to become standard on desktop computers.
Steve Jobs of Apple Computer toured the Xerox PARC facilities in 1979 and immediately recognized the utility of the GUI on the Alto. The design of Apple's Lisa computer, already under development, was changed to be GUI-based. Xerox also developed a GUI machine called the Star for the mass market, but both the Lisa and Star were flops due to their high price tags. It wasn't until the Macintosh was released in 1984 that the price point for mass-market appeal in a GUI machine was achieved.