XEROX ALTO

The 'Xerox Alto', developed at Xerox PARC in 1973, was an early minicomputer and the first computer to use the desktop metaphor and graphical user interface (GUI). While often cited as the first personal computer, other systems are also candidates,^[1] and the Alto was a Xerox research tool, not a commercial product.

Contents

Software

Diffusion and evolution

See also

Further reading

Reference

External links

Software

Early software for the Alto was written in the BCPL programming language, and later in the Mesa programming language, which was not widely used outside PARC but influenced several later languages, such as Modula. The Alto keyboard was lacking the underscore key, which had been appropriated for the left-arrow character used in Mesa for the assignment operator. This feature of the Alto keyboard may have been the source for the CamelCase style for compound identifiers. Another feature of the Alto was that it was microcode-programmable by the user.
The Alto helped popularize the use of raster graphics model for all output, including text and graphics. It also introduced the concept of the ''bit block transfer'' operation, or BitBLT, as the fundamental programming interface to the display. In spite of its small memory size, quite a number of innovative programs were written for the Alto, including the first WYSIWYG document preparation systems Bravo and Gypsy, editors for graphical data (bitmaps, printed circuit boards, integrated circuits, etc.), the first versions of the Smalltalk environment, and one of the first network-based multi-person computer games (Alto Trek by Gene Ball).

Diffusion and evolution

Technically, the Alto was a small minicomputer, but it could be considered a personal computer in the sense that it was used by a single person sitting at a desk, in contrast with the mainframes and other minicomputers of the era. It was never a commercial product, although several thousand were built. Universities, including MIT, Stanford, CMU, and the University of Rochester received donations of Altos including IFS file servers and Dover laser printers. These machines were the inspiration for the ETH Zürich Lilith and Three Rivers Company PERQ workstations, and the Stanford University Network (SUN) workstation, which was eventually marketed by a spin-off company, Sun Microsystems. The Apollo/Domain workstation and Apple Lisa also were heavily influenced by the Alto.
The Xerox Alto was used to design the next influential "D" series of workstations: the Dolphin, Dorado and Dandelion. A network router called Dicentra was also based on this design. Dolphin was a mid-line TTL design originally intended to be the Star workstation while Dorado had a very fast ECL based design. The original architecture for the Dandelion, based on the AMD Am2900 bitslice microprocessor technology, was presented as a paper design called ''Wildflower'' and was the low-cost design that became the actual Star workstation.
A trip to Xerox PARC by Apple Computer's Steve Jobs in 1979 led to the graphical user interface and mouse being integrated into the Apple Lisa and, later, the first Macintosh^[2]. Steve Jobs was shown the Smalltalk-80 programming environment, networking, and most importantly the WYSIWYG, mouse-driven GUI interface provided by the Alto.
Xerox created a product division (SDD) to commercialize the work of PARC, initially attempting to use the Dolphin as the basis for a workstation product. The Dandelion design became the Xerox 8010, which ran the Xerox Star workstation software. The Xerox 8010 was the first commercial product to incorporate a GUI, including icons, windows, and folders.
The Alto is now very rare and a valuable collector's item.

See also

★ Douglas Englebart and NLS

★ Mousepad

★ Alan Kay

★ BitBLT

★ Ethernet

★ Apple Macintosh

★ Apple Lisa

★ Xerox Star

Further reading

★ Michael A. Hiltzik, ''Dealers of Lightning: Xerox PARC and the Dawn of the Computer Age'' (HarperCollins, New York, 1999)

★ Douglas K. Smith, Robert C. Alexander, ''Fumbling the Future: How Xerox Invented, Then Ignored, the First Personal Computer'' (William Morrow, New York, 1988)

Reference

★ ''Alto User's Handbook'', Xerox PARC, September 1979
1. Personal Computer Milestones
2. PBS Triumph of the Nerds Television Program Transcripts: Part III

External links

★ Xerox Alto documents at bitsavers.org

★ At the DigiBarn museum

★ Xerox PARC History page

★ An article on the Xerox Alto in Byte magazine

★ The Alto in 1974 Video

★ A microcode-level Xerox Alto simulator

★ A lecture video of Butler Lampson describing Xerox Alto in depth. (length: 2h45m)