page_title: Xerox Alto
section_title: Software
hierarchical_section_title: Xerox Alto / Software
caption_attribution_description: 日本語: ContrAlto (Alto エミュレーター）で起動した同システムのスクリーンショット
context_page_description: The Xerox Alto is the first computer designed from its inception to support an operating system based on a graphical user interface, later using the desktop metaphor. The first machines were introduced on 1 March 1973, a decade before mass-market GUI machines became available.
  The Alto is contained in a relatively small cabinet and uses a custom central processing unit built from multiple SSI and MSI integrated circuits. Each machine cost tens of thousands of dollars despite its status as a personal computer. Only small numbers were built initially, but by the late 1970s, about 1,000 were in use at various Xerox laboratories, and about another 500 in several universities. Total production was about 2,000 systems.
  The Alto became well known in Silicon Valley and its GUI was increasingly seen as the future of computing. In 1979, Steve Jobs arranged a visit to Xerox PARC, during which Apple Computer personnel would receive demonstrations of Xerox technology in exchange for Xerox being able to purchase stock options in Apple. After two visits to see the Alto, Apple engineers used the concepts to introduce the Apple Lisa and Macintosh systems.
context_section_description: Early software for the Alto was written in the programming language BCPL, and later in Mesa, which was not widely used outside PARC but influenced several later languages, such as Modula. The Alto used an early version of ASCII which lacked the underscore character, instead having the left-arrow character used in ALGOL 60 and many derivatives for the assignment operator: this peculiarity may have been the source of the CamelCase style for compound identifiers. Altos were also microcode-programmable by users.
  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 (bit blit, BitBLT), as the fundamental programming interface to the display. Despite its small memory size, many innovative programs were written for the Alto, including:
  the first WYSIWYG document preparation systems, Bravo and Gypsy;
  the Laurel email tool, and its successor, Hardy
  the Sil vector graphics editor, used mainly for logic circuits, printed circuit board, and other technical diagrams;
  the Markup bitmap editor (an early paint program);
  the Draw graphical editor using lines & splines;
  the first WYSIWYG integrated circuit editor based on the work of Lynn Conway, Carver Mead, and the Mead & Conway revolution;
  the first versions of the Smalltalk environment
  Interlisp
  one of the first network-based multi-person video games (Alto Trek by Gene Ball).
  There was no spreadsheet or database software. The first electronic spreadsheet program, VisiCalc, did not arise until 1979.
caption: Smalltalk-76 aka interim Alan Kay's Dynabook OS
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