Xerox Alto - Wikipedia

Xerox Alto - Wikipedia Jump to content Main menu Main menu move to sidebar hide Navigation Main page Contents Current events Random article About Wikipedia Contact us Contribute Help Learn to edit Community portal Recent changes Upload file Special pages Search Search Appearance Donate Create account Log in Personal tools Donate Create account Log in Contents move to sidebar hide (Top) 1 History 2 Architecture 3 Software 4 Diffusion and evolution 5 Xerox and the Alto 6 See also 7 References 8 Further reading 9 External links Toggle the table of contents Xerox Alto 24 languages العربية Azərbaycanca Català Dansk Deutsch Español Eesti فارسی Suomi Français Galego Italiano 日本語 한국어 Latviešu Nederlands Norsk bokmål Polski Português Русский Türkçe Українська Oʻzbekcha / ўзбекча 中文 Edit links Article Talk English Read Edit View history Tools Tools move to sidebar hide Actions Read Edit View history General What links here Related changes Upload file Permanent link Page information Cite this page Get shortened URL Switch to legacy parser Print/export Download as PDF Printable version In other projects Wikimedia Commons Wikidata item Appearance move to sidebar hide From Wikipedia, the free encyclopedia Computer made by Xerox "},"units_shipped":{"wt":"Alto I: 120<br>Alto II: 2,000<ref>{{cite web|url=http://www.digibarn.com/collections/audio/digibarn-radio/ron-cude-xerox/ron-cude-xerox-fumbling-future-and-elixir.mp3|title=MP3 Audio of Ron Cude talking about the 1979 Boca Raton Alto Event|website=The DigiBarn Computer Museum|date=2003|archive-url=https://web.archive.org/web/20200918031608/http://www.digibarn.com/collections/audio/digibarn-radio/ron-cude-xerox/ron-cude-xerox-fumbling-future-and-elixir.mp3|archive-date=September 18, 2020|url-status=live}}</ref>"},"media":{"wt":"2.5 [[megabyte|MB]] one-platter [[disk pack#Disk cartridge|disk cartridge]]<ref name=alto/>"},"os":{"wt":"Alto Executive (Exec)"},"input":{"wt":"[[Computer keyboard|Keyboard]], 3-button [[Mouse (computing)|mouse]], 5-key [[chorded keyboard]]"},"power":{"wt":""},"cpu":{"wt":"[[transistor–transistor logic|TTL]]-based, with the [[arithmetic logic unit|ALU]] built around four [[74181]] [[medium-scale integration|MSI]] chips. It has user programmable [[microcode]], uses [[big-endian]] format and a [[CPU clock]] of {{nowrap|5.88 MHz}}.<ref>{{cite web|title=Alto I Schematics|url=http://bitsavers.org/pdf/xerox/alto/schematics/AltoI_Schematics.pdf|website=Bitsavers|access-date=July 21, 2016|page=54|archive-date=February 24, 2021|archive-url=https://web.archive.org/web/20210224014316/http://bitsavers.org/pdf/xerox/alto/schematics/AltoI_Schematics.pdf|url-status=live}}</ref><ref name=alto>{{cite web\n|title=History of Computers and Computing, Birth of the modern computer, Personal computer, Xerox Alto\n|access-date=April 19, 2016\n|url=http://history-computer.com/ModernComputer/Personal/Alto.html\n|archive-date=December 5, 2020\n|archive-url=https://web.archive.org/web/20201205082025/https://history-computer.com/ModernComputer/Personal/Alto.html\n|url-status=live\n}}</ref>"},"storage":{"wt":""},"memory":{"wt":"96<ref name=\"manual\">{{cite book|title=Alto Operating System Reference Manual|date=June 26, 1975|publisher=Xerox PARC|page=2|url=http://bitsavers.org/pdf/xerox/alto/memos_1975/Alto_Operating_System_Reference_Manual_Jun75.pdf|access-date=July 21, 2016|archive-date=July 17, 2019|archive-url=https://web.archive.org/web/20190717004756/http://bitsavers.org/pdf/xerox/alto/memos_1975/Alto_Operating_System_Reference_Manual_Jun75.pdf|url-status=live}}</ref> – 512 [[kilobyte|KB]] (128 KB for $4000)<ref name=alto/>"},"display":{"wt":"606 × 808 pixels<ref name=alto/>"},"audio":{"wt":""},"online_services":{"wt":""},"dimensions":{"wt":""},"weight":{"wt":""},"successor":{"wt":"[[Xerox Star]]"},"related":{"wt":"[[Lilith (computer)|ETH Lilith]]; {{br}}[[Apple Lisa|Lisa]]; {{br}}[[Apollo/Domain]]"}},"i":0}}]}'>Xerox AltoXerox Alto – exhibited at the Heinz Nixdorf MuseumsForum in Paderborn. Developer Xerox PARC Manufacturer Xerox PARC Released March 1, 1973; 53 years ago (1973-03-01) Introductory price US$32,000 (equivalent to $140,000 in 2025)[1] Units shipped Alto I: 120 Alto II: 2,000[2] Media 2.5 MB one-platter disk cartridge[3] Operating system Alto Executive (Exec) CPU TTL-based, with the ALU built around four 74181 MSI chips. It has user programmable microcode, uses big-endian format and a CPU clock of 5.88 MHz.[4][3] Memory 96[5] – 512 KB (128 KB for $4000)[3] Display 606 × 808 pixels[3] Input Keyboard, 3-button mouse, 5-key chorded keyboard Connectivity Ethernet Successor Xerox Star Related ETH Lilith; Lisa; Apollo/Domain The Xerox Alto is a computer system developed at Xerox PARC (Palo Alto Research Center) in the 1970s. It is considered one of the first workstations or personal computers, and its development pioneered many aspects of modern computing. The advances include graphical user interface (GUI), computer mouse, Ethernet networking, and the ability to run multiple applications simultaneously. It is one of the first computers to use a WYSIWYG (What You See Is What You Get) text editor and has a bit-mapped display. The Alto did not succeed commercially, but it had a significant influence on the development of future computer systems. The Alto was designed for an operating system based on a GUI, later using the desktop metaphor.[6][7] The first machines were introduced on March 1, 1973,[8] and in limited production starting one decade before Xerox's designs inspired Apple to release the first mass-market GUI computers. The Alto is contained in a relatively small cabinet and uses a custom central processing unit (CPU) built from multiple SSI and MSI integrated circuits. Each machine cost tens of thousands of dollars. Few 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 received demonstrations of Xerox technology in exchange for Xerox being able to purchase stock options in Apple.[9] After two visits to see the Alto, Apple engineers used the concepts in developing the Lisa and Macintosh systems. In 1981, Xerox commercialized a line of office computers, the Star, based on concepts from the Alto. A complete office system including several workstations, storage, and a laser printer cost up to $100,000 (equivalent to $350,000 in 2025). Like the Alto, the Star had little direct impact on the market. History [edit] "},"align":{"wt":""},"direction":{"wt":""},"background color":{"wt":""},"width":{"wt":""},"caption_align":{"wt":""},"image_style":{"wt":""},"image_gap":{"wt":"\n"},"header_background":{"wt":""},"header_align":{"wt":""},"header":{"wt":"Alto mouse\n"},"image1":{"wt":"Computer Museum of America (02).jpg"},"width1":{"wt":""},"alt1":{"wt":""},"link1":{"wt":""},"thumbtime1":{"wt":""},"caption1":{"wt":"The top three buttons\n"},"image2":{"wt":"Xerox Alto mouse bottom.jpg"},"width2":{"wt":"100"},"alt2":{"wt":""},"link2":{"wt":""},"thumbtime2":{"wt":""},"caption2":{"wt":"The underside has three rolling balls.\n"},"footer_background":{"wt":""},"footer_align":{"wt":""},"footer":{"wt":""}},"i":0}}]}'>Alto mouse The top three buttons The underside has three rolling balls. The Alto keyset is a chorded keyboard that never became popular. The Alto is the first computer with a graphical operating system, and was built on earlier graphical interface designs. It was conceived in 1972 in a memo written by Butler Lampson, inspired by the oN-Line System (NLS) developed by Douglas Engelbart and Dustin Lindberg at SRI International (SRI). Of further influence was the PLATO education system developed at the Computer-based Education Research Laboratory at the University of Illinois.[10] The Alto was designed mostly by Charles P. Thacker. Industrial Design and manufacturing was sub-contracted to Xerox's Special Programs Group in El Segundo, whose team included program manager Doug Stewart, operations manager Abbey Silverstone, and industrial designer Bob Nishimura. An initial run of 30 units was produced by the Special Programs Group, working with John Ellenby at PARC and Stewart and Silverstone at El Segundo, who were responsible for re-designing the Alto's electronics. Due to the success of the pilot run, the team went on to produce approximately 2,000 units over the next ten years.[11] Several Xerox Alto chassis are on display at the Computer History Museum in Mountain View, California, one is on display at the Mimms Museum of Technology and Art in Roswell, Georgia, and several are in private hands. Running systems are on display at the System Source Computer Museum in Hunt Valley, Maryland. Charles P. Thacker was awarded the 2009 Turing Award of the Association for Computing Machinery on March 9, 2010, for his pioneering design and realization of the Alto.[12] The 2004 Charles Stark Draper Prize was awarded to Thacker, Alan C. Kay, Butler Lampson, and Robert W. Taylor for their work on Alto.[13] On October 21, 2014, source code for Alto software, and other resources, were released by the Computer History Museum.[14] Architecture [edit] The following description is based mostly on the August 1976 Alto Hardware Manual by Xerox PARC.[15] Alto uses a microcoded design, but unlike many computers, the microcode engine is not hidden from the programmer in a layered design. Applications such as Pinball take advantage of this to accelerate performance. The Alto has a bit-slice arithmetic logic unit (ALU) based on the Texas Instruments 74181 chip, a ROM control store with a writable control store extension and has 128 (expandable to 512) KB of main memory organized in 16-bit words. Mass storage is provided by a hard disk drive that uses a removable 2.5 MB one-platter cartridge (Diablo Systems, a company Xerox later bought) similar to those used by the IBM 2310. The base machine and one disk drive are housed in a cabinet about the size of a small refrigerator; one more disk drive can be added via daisy-chaining. Alto both blurs and ignores the distinction between functional elements. Rather than a distinct central processing unit with a well-defined electrical interface (such as a system bus) to storage and peripherals, the Alto ALU interacts directly with hardware interfaces to memory and peripherals, driven by microinstructions that are output from the control store. The microcode machine supports up to 16 cooperative multitasking tasks, each with fixed priority. The emulator task executes the normal instruction set to which most applications are written; that instruction set is similar to a Data General Nova.[16] Other tasks serve the display, memory refresh, disk, network, and other I/O functions. For example, the bitmap display controller is little more than a 16-bit shift register; microcode moves display refresh data from main memory to the shift register, which serializes …