Early days: Xerox PARC Alto - History of the Desktop
The Xerox Alto, invented at the Xerox Palo Alto Research Center (PARC) in 1973, is widely seen as the first workstation and desktop computer as it was the first computer to offer a graphical user interface and a 3-button mouse, also invented at PARC. The system had a custom-built TTL 16-bit CPU based on the TI 74181, between 128 and 512 kB of memory, as well as a 2.5 MB single-platter cartridge as mass storage. Xerox used the Alto only internally and provided it for academic institutions. A claimed 2,000 units were built and a modified version called Star was sold in 1981 for $17,000.