NLS (computer system)
Encyclopedia
NLS, or the "oN-Line System", was a revolutionary computer collaboration system designed by Douglas Engelbart
and implemented by researchers at the Augmentation Research Center
(ARC) at the Stanford Research Institute
(SRI) during the 1960s. The NLS system was the first to employ the practical use of hypertext
links, the mouse (co-invented by Engelbart and colleague Bill English
), raster-scan
video monitors
, information organized by relevance, screen windowing
, presentation program
s, and other modern computing concepts. It was funded by the Defense Advanced Research Projects Agency, NASA
, and the U.S. Air Force.
developed his concepts while supported by the Air Force from 1959 to 1960, and published a framework in 1962.
The strange acronym, NLS (instead of OLS) was an artifact of the evolution of the system. His first computers were not able to support more than one user at a time.
First was the CDC 160A
in 1963 which had very little programming power of its own.
As a stopgap measure, the team developed a system where off-line users — that is, anyone not sitting at the one terminal available — could still edit their documents by punching a string of commands onto paper tape with a Flexowriter. Once the tape was complete, then the user would feed into the computer the paper tape on which the last document draft had been stored, followed by the new commands to be applied, and then the computer would print out a new paper tape containing the latest version of the document. Obviously, without interactive visualization
, this could be awkward and the user had to monitor the cumulative effects of his commands on his document in his or her own head. On the other hand, it matched the workflow of the 1960s office, since managers would give marked-up printouts of documents to secretaries.
The design continued to support this "off-line" workflow, as well as an interactive "on-line" ability to edit the same documents. To avoid two acronyms starting with the same letter, the Off-Line Text System was abbreviated FLTS, while the On-Line Text System was abbreviated NLTS. As the system evolved to support more than just text, the "T" was dropped and the interactive version became known as NLS.
Robert Taylor
, who had a background in psychology, provided support from NASA
. When Taylor moved to the Information Processing Techniques Office of the US Defense Department's Advanced Research Projects Agency, he was able to provide even more funding to the project.
In 1965, NLS development moved to a CDC 3100
.
Jeff Rulifson
joined SRI in 1966 and became the lead programmer for NLS until he left in 1973.
NLS development moved to a Scientific Data Systems SDS 940
computer running the Berkeley Timesharing System
in 1968.
It had an approximately 96 MB storage disk. It could support up to 16 workstations, which were composed of a raster-scan
monitor
, a three-button mouse, and a device known as a chord keyset. The input of typed text was sent from the keyboard to a specific subsystem that relayed the information along a bus to one of two Display Controllers and Display Generators. The inputted text then was sent to a 5-inch (127 mm) cathode ray tube
(CRT), which was enclosed by a special cover and a superimposed video image was then received by a professional-quality black-and-white TV camera. The TV camera information was then sent to the closed-circuit Camera Control and Patch Panel, and, finally, displayed on each workstation's video monitor.
NLS was demonstrated by Engelbart on December 9, 1968 to a large audience at that year's Fall Joint Computer Conference in San Francisco
. This has since been dubbed "The Mother of All Demos
", as it not only demonstrated the groundbreaking features of NLS, but also involved assembling some remarkable state-of-the-art video technologies. Engelbart's onstage terminal was linked to a massive video projector
loaned by the NASA Ames Research Center
and, via leased telephone
lines, to ARC's SDS 940 computer in Menlo Park
. On a 22-foot high screen with video insets, the audience could follow Engelbart's actions on his display, observe how he used the mouse, and watch as members of his team in Menlo Park
joined in the presentation.
One of NLS's most revolutionary features, the Journal, was developed in 1970 by Australian computer engineer David A. Evans as part of his doctoral thesis. The Journal was a primitive hypertext-based groupware program which can be seen as a predecessor (if not the direct ancestor) of all contemporary server software that supports collaborative document creation (like wiki
s). It was used by ARC members to discuss, debate, and refine concepts in the same way that wikis are being used today.
The journal was used to store documents for the Network Information Center
and early network email
archives.
Most Journal documents have been preserved in paper form, and are stored in Stanford University
's archives; they are a valuable record of the evolution of the ARC community from 1970 until commercialization began in 1976. An additional set of Journal documents exist at the Computer History Museum, along with a large collection of ARC backup tapes starting from the early 70's as well as some of the tapes from the 60's from the SDS 940.
The NLS was implemented using several domain-specific languages implemented with the Tree Meta compiler-compiler
. The eventual implementation language was called L10.
In 1970 NLS was ported to the PDP-10
computer (as modified by BBN
to run the TENEX operating system). By mid-1971 the TENEX implementation of NLS was put into service as the new Network Information Center, but even this computer could only handle a small number of simultaneous users. Access was possible via either custom-built display workstations, or simple typewrite-like terminals, less expensive and more common at the time.
By 1974 the NIC had spun off to a separate project on its own computer.
"Many of those firsts came right out of the staff's innovations—even had to be explained to me before I could understand them. They deserve more recognition." Douglas Engelbart
.
. NLS was not designed to be easy to learn; it employed the heavy use of program modes, relied on a strict hierarchical structure, did not have a point-and-click interface, and forced the user to have to learn cryptic mnemonic codes to do anything useful with the system. The chord keyset, which complemented the modal nature of NLS, forced the user to learn a 5-bit binary code if they did not want to use the keyboard. Finally, with the arrival of the ARPA Network
at SRI in 1969, the time-sharing technology that seemed practical with a small number of users became impractical over a distributed network
; time-sharing was rapidly being replaced by individual minicomputer
s (and later microcomputer
s) and workstation
s. Attempts to port NLS to other hardware, such as the PDP-10
and later on the DECSYSTEM-20
, were successful but did nothing to spread NLS beyond SRI.
Frustrated by the direction of Engelbart's "bootstrapping" crusade, many top SRI researchers left, with many ending up at the Xerox Palo Alto Research Center, taking the mouse idea with them. SRI sold NLS to Tymshare
in 1977 and renamed it Augment, and Tymshare was, in turn, sold to McDonnell Douglas
in 1984.
The HyPerform program sold by NDMA Inc. is a descendant of NLS and Augment.
Some of the "full-interaction" paradigm lives on in different systems, including the Hyperwords
Add-On for Mozilla
Firefox. The Hyperwords concept grew out the Engelbart web-documentary Invisible Revolution. The aim of the project is to allow users to interact with all the words on the web, not only the links. Hyperwords works through a simple hierarchical menu but also gives users access to keyboard 'phrases' in the spirit of NLS commands and features Views which are inspired by the powerful NLS ViewSpecs. The Views allow the user to re-format web pages on the fly. Englebart has been on the Advisory Board of The Hyperwords Company since its inception 2006.
From 2005 through 2008 a volunteer group from the Computer History Museum
attempted to restore the system.
Douglas Engelbart
Douglas Carl Engelbart is an American inventor, and an early computer and internet pioneer. He is best known for his work on the challenges of human-computer interaction, resulting in the invention of the computer mouse, and the development of hypertext, networked computers, and precursors to GUIs...
and implemented by researchers at the Augmentation Research Center
Augmentation Research Center
Stanford Research Institute's Augmentation Research Center was founded in the 1960s by electrical engineer Douglas Engelbart to develop and experiment with new tools and techniques for collaboration and information processing. The main product to come out of ARC was the revolutionary oN-Line...
(ARC) at the Stanford Research Institute
SRI International
SRI International , founded as Stanford Research Institute, is one of the world's largest contract research institutes. Based in Menlo Park, California, the trustees of Stanford University established it in 1946 as a center of innovation to support economic development in the region. It was later...
(SRI) during the 1960s. The NLS system was the first to employ the practical use of hypertext
Hypertext
Hypertext is text displayed on a computer or other electronic device with references to other text that the reader can immediately access, usually by a mouse click or keypress sequence. Apart from running text, hypertext may contain tables, images and other presentational devices. Hypertext is the...
links, the mouse (co-invented by Engelbart and colleague Bill English
Bill English (computer engineer)
William "Bill" English is a computer engineer who contributed to the development of the computer mouse while working for Douglas Engelbart at SRI International's Augmentation Research Center. He left SRI in 1971 and headed to Xerox PARC, where he managed the Office Systems Research Group...
), raster-scan
Raster scan
A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems...
video monitors
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
, information organized by relevance, screen windowing
Gui
Gui or guee is a generic term to refer to grilled dishes in Korean cuisine. These most commonly have meat or fish as their primary ingredient, but may in some cases also comprise grilled vegetables or other vegetarian ingredients. The term derives from the verb, "gupda" in Korean, which literally...
, presentation program
Presentation program
A presentation program is a computer software package used to display information, normally in the form of a slide show...
s, and other modern computing concepts. It was funded by the Defense Advanced Research Projects Agency, NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
, and the U.S. Air Force.
Development
Douglas EngelbartDouglas Engelbart
Douglas Carl Engelbart is an American inventor, and an early computer and internet pioneer. He is best known for his work on the challenges of human-computer interaction, resulting in the invention of the computer mouse, and the development of hypertext, networked computers, and precursors to GUIs...
developed his concepts while supported by the Air Force from 1959 to 1960, and published a framework in 1962.
The strange acronym, NLS (instead of OLS) was an artifact of the evolution of the system. His first computers were not able to support more than one user at a time.
First was the CDC 160A
CDC 160A
The CDC 160 and CDC 160-A were 12-bit minicomputers built by Control Data Corporation from 1960 to 1965. The 160 was designed by Seymour Cray - reportedly over a long three-day weekend...
in 1963 which had very little programming power of its own.
As a stopgap measure, the team developed a system where off-line users — that is, anyone not sitting at the one terminal available — could still edit their documents by punching a string of commands onto paper tape with a Flexowriter. Once the tape was complete, then the user would feed into the computer the paper tape on which the last document draft had been stored, followed by the new commands to be applied, and then the computer would print out a new paper tape containing the latest version of the document. Obviously, without interactive visualization
Feedback
Feedback describes the situation when output from an event or phenomenon in the past will influence an occurrence or occurrences of the same Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence an occurrence or...
, this could be awkward and the user had to monitor the cumulative effects of his commands on his document in his or her own head. On the other hand, it matched the workflow of the 1960s office, since managers would give marked-up printouts of documents to secretaries.
The design continued to support this "off-line" workflow, as well as an interactive "on-line" ability to edit the same documents. To avoid two acronyms starting with the same letter, the Off-Line Text System was abbreviated FLTS, while the On-Line Text System was abbreviated NLTS. As the system evolved to support more than just text, the "T" was dropped and the interactive version became known as NLS.
Robert Taylor
Robert Taylor (computer scientist)
Robert William Taylor , known as Bob Taylor, is an Internet pioneer, who led teams that made major contributions to the personal computer, and other related technologies....
, who had a background in psychology, provided support from NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
. When Taylor moved to the Information Processing Techniques Office of the US Defense Department's Advanced Research Projects Agency, he was able to provide even more funding to the project.
In 1965, NLS development moved to a CDC 3100
CDC 3000
The CDC 3000 series computers from Control Data Corporation were mid-1960s follow-ons to the CDC 1604 and CDC 924 systems. Over time, a range of machines were produced - divided into the 'upper 3000 series' and the 'lower 3000 series'. CDC phased out production of the 3000 series in the early 1970s...
.
Jeff Rulifson
Jeff Rulifson
Johns Frederick Rulifson is an American computer scientist.-Biography:Johns Frederick Rulifson was born August 20, 1941 in Bellefontaine, Ohio. His father was Erwin Charles Rulifson and mother was Virginia Helen Johns...
joined SRI in 1966 and became the lead programmer for NLS until he left in 1973.
NLS development moved to a Scientific Data Systems SDS 940
SDS 940
The SDS 940 was Scientific Data Systems' first machine designed to support time sharing directly, and was based on the SDS 930's 24-bit CPU built primarily of integrated circuits. It was announced in February 1966 and shipped in April, becoming a major part of Tymshare's expansion during the 1960s...
computer running the Berkeley Timesharing System
Berkeley Timesharing System
The Berkeley Timesharing System was a pioneering time-sharing operating system implemented between 1964 and 1967 at the University of California, Berkeley...
in 1968.
It had an approximately 96 MB storage disk. It could support up to 16 workstations, which were composed of a raster-scan
Raster scan
A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems...
monitor
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
, a three-button mouse, and a device known as a chord keyset. The input of typed text was sent from the keyboard to a specific subsystem that relayed the information along a bus to one of two Display Controllers and Display Generators. The inputted text then was sent to a 5-inch (127 mm) cathode ray tube
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
(CRT), which was enclosed by a special cover and a superimposed video image was then received by a professional-quality black-and-white TV camera. The TV camera information was then sent to the closed-circuit Camera Control and Patch Panel, and, finally, displayed on each workstation's video monitor.
San Francisco, California
San Francisco , officially the City and County of San Francisco, is the financial, cultural, and transportation center of the San Francisco Bay Area, a region of 7.15 million people which includes San Jose and Oakland...
. This has since been dubbed "The Mother of All Demos
The Mother of All Demos
The Mother of All Demos is a name given to Douglas Engelbart's December 9, 1968, demonstration of experimental computer technologies that are now commonplace...
", as it not only demonstrated the groundbreaking features of NLS, but also involved assembling some remarkable state-of-the-art video technologies. Engelbart's onstage terminal was linked to a massive video projector
Video projector
A video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other...
loaned by the NASA Ames Research Center
NASA Ames Research Center
The Ames Research Center , is one of the United States of America's National Aeronautics and Space Administration 10 major field centers.The centre is located in Moffett Field in California's Silicon Valley, near the high-tech companies, entrepreneurial ventures, universities, and other...
and, via leased telephone
Telephone
The telephone , colloquially referred to as a phone, is a telecommunications device that transmits and receives sounds, usually the human voice. Telephones are a point-to-point communication system whose most basic function is to allow two people separated by large distances to talk to each other...
lines, to ARC's SDS 940 computer in Menlo Park
Menlo Park, California
Menlo Park, California is a city at the eastern edge of San Mateo County, in the San Francisco Bay Area of California, in the United States. It is bordered by San Francisco Bay on the north and east; East Palo Alto, Palo Alto, and Stanford to the south; Atherton, North Fair Oaks, and Redwood City...
. On a 22-foot high screen with video insets, the audience could follow Engelbart's actions on his display, observe how he used the mouse, and watch as members of his team in Menlo Park
Menlo Park, California
Menlo Park, California is a city at the eastern edge of San Mateo County, in the San Francisco Bay Area of California, in the United States. It is bordered by San Francisco Bay on the north and east; East Palo Alto, Palo Alto, and Stanford to the south; Atherton, North Fair Oaks, and Redwood City...
joined in the presentation.
One of NLS's most revolutionary features, the Journal, was developed in 1970 by Australian computer engineer David A. Evans as part of his doctoral thesis. The Journal was a primitive hypertext-based groupware program which can be seen as a predecessor (if not the direct ancestor) of all contemporary server software that supports collaborative document creation (like wiki
Wiki
A wiki is a website that allows the creation and editing of any number of interlinked web pages via a web browser using a simplified markup language or a WYSIWYG text editor. Wikis are typically powered by wiki software and are often used collaboratively by multiple users. Examples include...
s). It was used by ARC members to discuss, debate, and refine concepts in the same way that wikis are being used today.
The journal was used to store documents for the Network Information Center
InterNIC
The Internet Network Information Center, known as InterNIC, was the Internet governing body primarily responsible for domain name and IP address allocations from 1972 until September 18, 1998 when this role was assumed by the Internet Corporation for Assigned Names and Numbers...
and early network email
Email
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
archives.
Most Journal documents have been preserved in paper form, and are stored in Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
's archives; they are a valuable record of the evolution of the ARC community from 1970 until commercialization began in 1976. An additional set of Journal documents exist at the Computer History Museum, along with a large collection of ARC backup tapes starting from the early 70's as well as some of the tapes from the 60's from the SDS 940.
The NLS was implemented using several domain-specific languages implemented with the Tree Meta compiler-compiler
Compiler-compiler
A compiler-compiler or compiler generator is a tool that creates a parser, interpreter, or compiler from some form of formal description of a language and machine...
. The eventual implementation language was called L10.
In 1970 NLS was ported to the PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
computer (as modified by BBN
BBN Technologies
BBN Technologies is a high-technology company which provides research and development services. BBN is based next to Fresh Pond in Cambridge, Massachusetts, USA...
to run the TENEX operating system). By mid-1971 the TENEX implementation of NLS was put into service as the new Network Information Center, but even this computer could only handle a small number of simultaneous users. Access was possible via either custom-built display workstations, or simple typewrite-like terminals, less expensive and more common at the time.
By 1974 the NIC had spun off to a separate project on its own computer.
Firsts
All of the features of NLS were in support of Engelbart's goal of augmenting collective knowledge work and therefore focused on making the user more powerful, not simply on making the system easier to use. The features listed therefore supported a full-interaction paradigm with rich interaction possibilities for a trained user, rather than what Engelbart refers to as the WYSIAYG (What You See Is All You Get) paradigm that came later.- the computer mouse
- 2-dimensional display editing
- in-file object addressing, linking
- hypermedia
- outline processing
- flexible view control
- multiple windows
- cross-file editing
- integrated hypermedia email
- hypermedia publishing
- document version control
- shared-screen teleconferencing
- computer-aided meetings
- formatting directives
- context-sensitive help
- distributed client-server architecture
- uniform command syntax
- universal "user interface" front-end module
- multi-tool integration
- grammar-driven command language interpreter
- protocols for virtual terminals
- remote procedure call protocols
- compilable "Command Meta Language"
"Many of those firsts came right out of the staff's innovations—even had to be explained to me before I could understand them. They deserve more recognition." Douglas Engelbart
Douglas Engelbart
Douglas Carl Engelbart is an American inventor, and an early computer and internet pioneer. He is best known for his work on the challenges of human-computer interaction, resulting in the invention of the computer mouse, and the development of hypertext, networked computers, and precursors to GUIs...
.
Decline and succession
The downfall of NLS, and subsequently, of ARC in general, was the program's difficult learning curveLearning curve
A learning curve is a graphical representation of the changing rate of learning for a given activity or tool. Typically, the increase in retention of information is sharpest after the initial attempts, and then gradually evens out, meaning that less and less new information is retained after each...
. NLS was not designed to be easy to learn; it employed the heavy use of program modes, relied on a strict hierarchical structure, did not have a point-and-click interface, and forced the user to have to learn cryptic mnemonic codes to do anything useful with the system. The chord keyset, which complemented the modal nature of NLS, forced the user to learn a 5-bit binary code if they did not want to use the keyboard. Finally, with the arrival of the ARPA Network
ARPANET
The Advanced Research Projects Agency Network , was the world's first operational packet switching network and the core network of a set that came to compose the global Internet...
at SRI in 1969, the time-sharing technology that seemed practical with a small number of users became impractical over a distributed network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
; time-sharing was rapidly being replaced by individual minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
s (and later microcomputer
Microcomputer
A microcomputer is a computer with a microprocessor as its central processing unit. They are physically small compared to mainframe and minicomputers...
s) and workstation
Workstation
A workstation is a high-end microcomputer designed for technical or scientific applications. Intended primarily to be used by one person at a time, they are commonly connected to a local area network and run multi-user operating systems...
s. Attempts to port NLS to other hardware, such as the PDP-10
PDP-10
The PDP-10 was a mainframe computer family manufactured by Digital Equipment Corporation from the late 1960s on; the name stands for "Programmed Data Processor model 10". The first model was delivered in 1966...
and later on the DECSYSTEM-20
DECSYSTEM-20
The DECSYSTEM-20 was a 36-bit Digital Equipment Corporation PDP-10 mainframe computer running the TOPS-20 operating system.PDP-10 computers running the TOPS-10 operating system were labeled DECsystem-10 as a way of differentiating them from the PDP-11...
, were successful but did nothing to spread NLS beyond SRI.
Frustrated by the direction of Engelbart's "bootstrapping" crusade, many top SRI researchers left, with many ending up at the Xerox Palo Alto Research Center, taking the mouse idea with them. SRI sold NLS to Tymshare
Tymshare
Tymshare, Inc. was headquartered in Cupertino, California from 1964 to 1984.It was a well-known timesharing service and third-party hardware maintenance company throughout its history and competed with companies such as Four Phase, Compuserve, and Digital Equipment Corporation...
in 1977 and renamed it Augment, and Tymshare was, in turn, sold to McDonnell Douglas
McDonnell Douglas
McDonnell Douglas was a major American aerospace manufacturer and defense contractor, producing a number of famous commercial and military aircraft. It formed from a merger of McDonnell Aircraft and Douglas Aircraft in 1967. McDonnell Douglas was based at Lambert-St. Louis International Airport...
in 1984.
The HyPerform program sold by NDMA Inc. is a descendant of NLS and Augment.
Some of the "full-interaction" paradigm lives on in different systems, including the Hyperwords
Hyperwords
Hyperwords was a term for interactive text. Whereas hyper-links have the specific meaning of words which are linked to specific destinations, hyperwords refers to all interactive words where the idea is that the reader can issue commands on the text...
Add-On for Mozilla
Mozilla
Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....
Firefox. The Hyperwords concept grew out the Engelbart web-documentary Invisible Revolution. The aim of the project is to allow users to interact with all the words on the web, not only the links. Hyperwords works through a simple hierarchical menu but also gives users access to keyboard 'phrases' in the spirit of NLS commands and features Views which are inspired by the powerful NLS ViewSpecs. The Views allow the user to re-format web pages on the fly. Englebart has been on the Advisory Board of The Hyperwords Company since its inception 2006.
From 2005 through 2008 a volunteer group from the Computer History Museum
Computer History Museum
The Computer History Museum is a museum established in 1996 in Mountain View, California, USA. The Museum is dedicated to preserving and presenting the stories and artifacts of the information age, and exploring the computing revolution and its impact on our lives.-History:The museum's origins...
attempted to restore the system.
External links
- On the Doug Engelbart Institute website see especially the 1968 Demo resources page for links to the demo and to later panel discussions by participants in the demo; About NLS/Augment; Engelbart's Bibliography, Videography; and the Engelbart Archives Special Collections page.
- The original 1968 Demo as streaming RealVideo clips
- A high-resolution version of the 1968 Demo video
- HyperScope, a browser-based project to recreate and extend NLS/Augment Douglas Engelbart himself is involved in this project
- OpenAugment, another NLS/Augment implementation
- NLS documents at bitsavers.org