The Xerox “Star” A Retrospective By Bruno Nadeau & Luv Sharma.

The Xerox “Star”A Retrospective

By Bruno Nadeau & Luv Sharma

Overview

• What is the “Star”• Features – What Makes it Unique• History of Star Development• Xerox PARC• Lessons Learned

Although Star was conceived as a product in 1975 and released in 1981, the history of its development dates back three decades.

Memex(1945)

• Vannevar Bush describes his vision of a personal, desktop computer.

• This was when computers were new, room-sized and used in military applications.

• The idea languishes because of “insufficient technology and imagination”.

Memex(1945)

• Vannevar Bush describes his vision of a personal, desktop computer.

• This was when computers were new, room-sized and used in military applications.

• The idea languishes because of “insufficient technology and imagination”.

Sketchpad(1960s)

• Ivan Sutherland builds an interactive graphics system that allows a user to create graphical figures on a CRT display using a light pen.

• These figures were treated as objects and could be moved, copied, shrunk, expanded, rotated etc.

• Sketchpad heavily influenced Star’s user interface and graphic applications.

Sketchpad(1960s)

• Ivan Sutherland builds an interactive graphics system that allows a user to create graphical figures on a CRT display using a light pen.

• These figures were treated as objects and could be moved, copied, shrunk, expanded, rotated etc.

• Sketchpad heavily influenced Star’s user interface.

NLS(1960s)

• Douglas Engelbart establishes a research program at Stanford Research Institute(SRI).

• Experiments with different types of displays and input devices.

• Invents the mouse.• Develops a system commonly called NLS.

NLS(1960s)

• NLS was different– It used CRT displays and not teletypes.– It was interactive(online) when almost all

computing was batch.– Full-screen oriented when other interactive

systems were line-oriented.– It had a Mouse!– First system to organize information in trees

and networks.

The Reactive Engine(1969)

– Alan Kay, a graduate student at the time, in his dissertation, developed many ideas that found their way into Star.

– Later, he brought to fruition these ideas in the Smalltalk programming language.

– Like the developers of NLS, he realized “interactive applications do not have to treat the display as a glass teletype and can share the screen with other programs”

Xerox PARC(1970)

• Palo Alto Research Center - several laboratories devoted to basic and applied research in materials science, laser physics, integrated circuitry, CAD, user interfaces etc.

• Researchers at PARC were fond of the slogan - the best way to predict the future is to invent it. So they began searching for a new approach to computing.

Xerox PARC(1970)• Among the founding members of PARC was Alan

Kay, who liked the novel approach to HCI followed by NLS.

• As a result, PARC hired several people who had worked on NLS.

• In 1971, PARC signed agreement with SRI licensing Xerox to use the mouse.

• One major outcome of this new approach was the Alto.

Alto(1972)

• Mini-computer with removable 2.5 mb hard disk pack.

• 128-256 kb memory.

• Microprogrammable instruction set.

• Full-page bitmapped graphic display.

• 50 kb of high-speed display memory.

• A mouse.

Ethernet

• Standardized layered communication protocols.

• Used to network the newly built Alto computers.

Smalltalk• Language and programming environment.• Refined and solidified concepts of object-

oriented programming.• Most importantly for Star, Smalltalk

demonstrated power of:– Graphical, bitmapped displays;– Mouse-driven input;– Windows and– Simultaneous applications.

Pygmalion• Doctoral thesis project of David C. Smith.• Demonstrated

– programming is not necessarily textual; it can be done by interacting with graphical elements on screen;

– computers can be programmed in the language of the user interface;

– the idea of using icons for direct manipulation.

Bravo, Gypsy and BravoX• Charles Simolyn and Butler Lampson write

advanced document editing system called Bravo(1976-78).[WYSIWYG]

• Exemplifying modelessness, Larry Tesler writes another text-editor: Gypsy.

• Simonyl and others add style and users’ ability to control the appearance of their documents: BravoX.

Draw, Sil, Markup, Flyer and Doodle

• Draw and Sil: Graphical object editors that allowed users to construct figures out of selectable, movable, stretchable geometric forms and text.

• Markup: Bitmap graphics editor(like paint).• Flyer: Another paint program written in Smalltalk

for Alto.• Doodle: The above inspired Doodle for a later

machine, eventually evolving into Viewpoint’s Free-Hand Drawing application.

Laser Printing• Invented at PARC.• Press page-description language

developed (uniform way to describe output to printers).

• Press -> Interpress (Xerox’s commercial page-description language) -> Postscript(Adobe’s page-description language).

Laurel and Hardy

• Though e-mail was not invented at PARC, it was made more accessible to non-engineers through Laurel(display-oriented tool for sending, receiving and organizing e-mail).

• Laurel inspires Hardy for a successor of Alto.

Officetalk

• Prototype office automation system.

• Supported standard office automation tasks.

• Tracked jobs that went from person to person in an organization.

Star(1981)• Contrary to popular belief, Star was not

developed at PARC.

• Separate organization called System Development Department(split between southern, El Segundo and northern California, Palo Alto).

• SDD used Mesa, a ‘dialect’ of Pascal as the primary product programming language.

Star-Hardware

• 8000 series network system processor• 384 kb of real memory• A local harddisk - 10,20 or 40 mb• 17 inch display• Mechanical mouse• 8 inch floppy disk drive• Ethernet connection.

$ 16,000 only!

Star-Software

Mammoth task to integrate all the software described above into one coherent design.

About 30 person-years went into the design of the interface, functionality and hardware.

Objects and actions: objects that users can manipulate and actions that software provided for this manipulation.

Star(1981)• Since the SDD was split in two locations, it had to

come up with an effective means of communication.

• Ethernet: 56kbps lease line.

• Design and Prototyping - Palo Alto; Implementation - El Segundo.

Tajo/XDE

• Since the machine was developed in parallel with the software, it was not available initially as a development platform.

• So early prototyping and development done on Altos.

• When the 8000 series workstations were available, the systems group developed XDE, known internally as Tajo.

Success?

• In spite of such exemplary vision, Star is considered a commercial failure. So why did Star fail?– Too expensive at $16,000?– Ahead of its time?– Not marketed well?– Too monolithic?

Lessons from experience

• Pay attention to industry trends• Pay attention to what customers want• Know your competition• Establish firm performance goals• Avoid geographically spilt organizations• Don’t be dogmatic about Desktop

metaphor and direct manipulation

What was right

• Iconic, direct manipulation, object-oriented user interface

• Generic commands and consistency• Pointing device• High resolution display• Good graphic design• 16-bit character set• Distributed personal computing