Over three decades of work by diverse engineers and researchers intent on
learning how best to interact with a computer come together in the windows and
icons used today
Reprinted from IEEE Spectrum, September 1989, pp. 46-51.
Mice, windows, icons, and menus: these are the ingredients of computer interfaces designed
to be easy to grasp, simplicity itself to use, and straightforward to describe. The
mouse is a pointer. Windows divide up the screen. Icons symbolize application programs and
data. Menus list choices of action.
But the development of today’s graphical user interface was anything but simple.
It took some 30 years of effort by engineers and computer scientists in universities,
government laboratories, and corporate research groups, piggybacking on each other’s
work, trying new ideas, repeating each other’s mistakes.
Throughout the 1970s and early 1980s, many of the early concepts for windows, menus,
icons, and mice were arduously researched at Xerox Corp.’s Palo Alto Research
Center (PARC), Palo Alto, Calif. In 1973, PARC developed the prototype Alto, the first
of two computers that would prove seminal in this area. More than 1200 Altos were built
and tested. From the Alto’s concepts, starting in 1975, Xerox’s System
Development Department then developed the Star and introduced it in 1981 – the
first such user-friendly machine sold to the public.
In 1984, the low-cost Macintosh from Apple Computer Inc., Cupertino, Calif., brought the
friendly interface to thousands of personal computer users. During the next five
years, the price of RAM chips fell enough to accommodate the huge memory demands of
bit-mapped graphics, and the Mac was followed by dozens of similar interfaces for
PCs and workstations of all kinds. By now, application programmers are becoming familiar
with the idea of manipulating graphic objects.
The Mac’s success during the 1980s spurred Apple Computer to pursue legal action over
ownership of many features of the graphical user interface. Suits now being litigated
could assign those innovations not to the designers and their companies, but to
those who first filed for legal protection on them.
The grandfather of the graphical user interface was Sketchpad [see photograph].
Massachusetts Institute of Technology student Ivan E. Sutherland built it in 1962 as
a Ph.D. thesis at MIT’s Lincoln Laboratory in Lexington, Mass. Sketchpad users
could not only draw points, line segments, and circular arcs on a cathode ray
tube (CRT) with a light pen-they could also assign constraints to, and relationships
among, whatever they drew.
|Sketchpad, created in 1962 by Ivan Sutherland at Massachusetts Institute of Technology’s Lincoln Laboratory in Lexington, is considered the first computer with a windowing interface.|
Arcs could have a specified diameter, lines could be horizontal or vertical, and figures
could be built up from combinations of elements and shapes. Figures could be
moved, copied, shrunk, expanded, and rotated, with their constraints (shown as onscreen
icons) dynamically preserved. At a time when a CRT monitor was a novelty in itself,
the idea that users could interactively create objects by drawing on a computer was
Moreover, to zoom in on objects, Sutherland wrote the first window-drawing program,
which inquired him to come up with the first clipping algorithm. Clipping is a
software routine that calculates which part of a graphic object is to be displayed,
and displays only that part on the screen. The program must calculate where a line is
to be drawen, compare that position to the coordinates of the window in use, and
prevent the display of any line segment whose coordinates fall outside the window.
Though films of Sketchpad in operation were widely shown in the computer research
community, Sutherland says today that there was little immediate fallout from
the project. Running on MIT’s TX-2 mainframe, it demanded too much computing
power to be practical for individual use. Many other engineers, however, see
Sketchpad’s design and algorithms as a primary influence on an entire generation
of research into user interfaces.
The mouse tale
The light pens used to select areas of the screen by interactive computer systems of
the 1950s and 1960s – including Sketchpad – had drawbacks. To do the
pointing, the user’s arm had to be lifted up from the table, and after a
while that got tiring. Picking up the pen required fumbling around on the table or,
if it had a holder, taking the time after making a selection to put it back.
Sensing an object with a light pen was straightforward: the computer displayed
spots of light on the screen and interrogated the pen as to whether it sensed
a spot, so the program always knew just what was being displayed. Locating the
position of the pen on the screen required more sophisticated techniques –
like displaying a cross pattern of nine points on the screen, then moving the cross
until it centered on the light pen.
In 1964, Douglas Engelbart, a research project leader at SRI International in Menlo
Park, Calif., tested all the commercially available pointing devices, from the
still-popular light pen to a joystick and a Graphicon (a curve-tracing device that
used a pen mounted on the arm of a potentiometer). But he felt the selection failed
to cover the full spectrum of possible pointing devices, and somehow he
should fill in the blanks.
Then he remembered a 1940s college class he had taken that covered the use of
a planimeter to calculate area. (A planimeter has two arms, with a wheel on each.
The wheels can roll only along their axes; when one of them rolls, the
other must slide.)
If a potentiometer were attached to each wheel to monitor its rotation, he thought,
a planimeter could be used as a pointing device. Engelbart explained his roughly
sketched idea to engineer William English, who with the help of the SRI machine shop
built what they quickly dubbed “the mouse.”
This first mouse was big because it used single-turn potentiometers: one rotation of
the wheels had to be scaled to move a cursor from one side of the screen to
the other. But it was simple to interface with the computer: the processor just read frequent
samples of the potentiometer positioning signals through analog-to-digital
The cursor moved by the mouse was easy to locate, since readings from the
potentiometer determined the position of the cursor on the screen – unlike the
light pen. But programmers for later windowing systems found that the
software necessary to determine which object the mouse had selected was more complex
than that for the light pen: they had to compare the mouse’s position with that
of all the objects displayed onscreen.
|More than 1200 of the experimental Alto, developed in 1973 by the Xerox Palo Alto Research Center, were distributed to test its windows, menus, and mouse.|
Going to the ball
Engelbart’s group at SRI ran controlled experiments with mice and other
pointing devices, and the mouse won hands down. People adapted to it quickly, it
was easy to grab, and it stayed where they put it. Still, Engelbart wanted to
tinker with it. After experimenting, his group had concluded that the proper ratio
of cursor movement to mouse movement was about 2:1, but he wanted to try varying
that ratio – decreasing it at slow speeds and raising it at fast speeds – to
improve user control of fine movements and speed up larger movements. Some modern
mouse-control software incorporates this idea, including that of the Macintosh.
The mouse, still experimental at this stage, did not change until 1971. Several
members of Engelbart’s group had moved to the newly established PARC, where many
other researchers had seen the SRI mouse and the test report. They decided there
was no need to repeat the tests; any experimental systems they designed would use mice.
Said English, “This was my second chance to build a mouse; it was obvious that
it should be a lot smaller, and that it should be digital.” Chuck Thacker, then a
member of the research staff, advised PARC to hire inventor Jack Hawley to build it.
Hawley decided the mouse should use shaft encoders, which measure position by a series
of pulses, instead of potentiometers (both were covered in Engelbart’s 1970
patent), to eliminate the expensive analog-to-digital converters. The basic principle,
of one wheel rolling while the other slid, was licensed from SRI.
In 1972, the mouse changed again. Ron Rider, now vice president of systems architecture at
PARC but then a new arrival, said he was using the wheel mouse while an engineer made
excuses for its asymmetric operation (one wheel dragging while one turned). “I
suggested that they turn a trackball upside down, make it small, and use it as
a mouse instead,” Rider told IEEE Spectrum. This device came to be known as the
ball mouse. “Easiest patent I ever got,” Rider said. “It took
me five minutes to think of, half an hour to describe to the attorney, and I was done.”
In the PARC ball mouse design, the weight of the mouse is transfered to the ball
by a swivel device and on one or two casters at the end of the mouse farthest from
the wire “tail.” A prototype was built by Xerox’s Electronics Division
in El Segundo, Calif., then redesigned by Hawley. The rolling ball turned two
perpendicular shafts, with a drum on the end of each that was coated with
alternating stripes of conductive and nonconductive material. As the drum turned,
the stripes transmitted electrical impulses through metal wipers.
When Apple Computer decided in 1979 to design a mouse for its Lisa computer, the design
mutated yet again. Instead of a metal ball held against the substrate by a
swivel, Apple used a rubber ball whose traction depended on the friction of the
rubber and the weight of the ball itself. Simple pads on the bottom of the case carried
the weight, and optical scanners detected the motion of the internal wheels. The
device had loose tolerances and few moving parts, so that it cost perhaps a quarter
as much to build as previous ball mice.
The first, wooden, SRI mouse had only one button, to test the concept. The plastic batch
of SRI mice had three side-by-side buttons – all there was room for, Engelbart
said. The first PARC mouse had a column of three buttons – again, because that best
fit the mechanical design. Today, the Apple mouse has one button, while the
rest have two or three. The issue is no longer technology – a standard 6-by-10-cm
mouse could now have dozen of buttons – but human factors, and the experts have
|Development of the graphical user interface, originally scattered, gradually came to center on the work done by Xerox during the 1970s, most notably development of the Alto computer and then design and production of the Star. Then Apple Computer Inc. incorporated the interface into its Lisa in 1983 and its Macintosh in 1984. All of today graphical interfaces hark back to this handful of machines.|
Said English, now director of internationalization at Sun Microsystems Inc., Mountain
View, Calif.: “Two or three buttons, that’s the debate. Apple made a bad
choice when they used only one.” He sees two buttons as the minimum because two
functions are basic to selecting an object: pointing to its start, then extending the
motion to the end of the object.
William Verplank, a human factor specialist in the group that tested th graphical
interface at Xerox from 1971 into the early 1980s, concurred. He told Spectrum
that with three buttons, Alto users forgot which button did what. The group’s
tests showed that one button was also confusing, because it required actions such
as double-clicking to select and then open a file.
“We have agonizing videos of naive users struggling” with these problems,
Verplank said. They concluded that for most users, two buttons (as used on the Star)
are optimal, if a button means the same thing in every application. English
experimented with one-button mice at PARC before concluding they were a bad idea.
But many interface designers dislike multiple buttons, saying that double clicking
a single button to select an item is easier than remembering which button points
and which extends. Larry Tesler, formerly a computer scientist at PARC, brought
the one-button mouse to Apple where he is now vice president of advanced
technology. The company’s rationale is that to attract novices to its
computers one button was as simple as it could get.
More than two million one-button Apple mice are now in use. The Xerox and
Microsoft two-button mice are less common than either Apple’s ubiquitous
one-button model or the three-button mice found on technical workstations.
Dozens of companies manufacture mice today; most are slightly smaller than
a pack of cigarettes, with minor variations in shape.
Window with view
In 1962, Sketchpad could split it screen horizontally into two independent
sections. One section could, for example, give a close-up view of the
object in the other section. Researchers call Sketchpad the first example
of tiled windows, which are laid out side by side. They differ from overlapping
windows, which can be stacked on top of each other, or overlaid, obscuring all
or part of the lower layers.
Windows were an obvious means of adding functionality to a small screen.
In 1969, Engelbart equipped NLS (as the On-Line System he invented at SRI
during the 1960s was known, to distinguish it from the Off-Line System
known as FLS) with windows. They split the screen into multiple parts
horizontally or vertically, and introduced cross-window editing with a mouse.
By 1972, led by researcher Alan Kay, the Smalltalk programming language
group at Xerox PARC had implemented their version of windows. They were
working with far different technology from Sutherland or Engelbart: by
deciding that their images had to be displayed as dots on the screen,
they led a move from vector to raster displays, to make it simple
to map the assigned memory location of each of those spots. This was
the bit map invented at PARC, and made viable during the 1980s by
continual performance improvements in processor logic and memory
Experimenting with bit-map manipulation, Smalltalk researcher Dan
Ingalls developed the bit-block transfer procedure, known as
BitBlt. The BitBlt software enabled application programs to mix and
manipulate rectangular arrays of pixel values in on-screen
or off-screen memory, or between the two, combining the pixel values
and storing the result in the appropriate bit-map location.
BitBlt made it much easier to write programs to scroll a
window (move an image through it), resize (enlarge or contract) it,
and drag windows (move them from one location to another
onscreen). It led Kay to create overlapping windows. They were soon
implemented by the Smalltalk group, but made clipping harder.
In a tiling system, explained researcher Peter Deutsch, who
worked with the Smalltalk group, the clipping borders are simply
horizontal or vertical lines from one screen border to another,
and software just tracks the location of those lines. But overlapping
windows may appear anywhere on the screen, randomly obscuring bits and
pieces of other windows, so that quite irregular regions must be
clipped. Thus application software must constantly track which portions
of their windows remain visible.
Some researchers still question
whether overlapping windows offer more benefits than tiled, at
least above a certain screen size, on the grounds that screens
with overlapping windows become so messy the user gets lost.
Others argue that overlapping windows more closely match
users’ work patterns, since no one arranges the papers
on their physical desktop in neat horizontal and vertical rows. Among
software engineers, however, overlapping windows seem to
have won for the user interface world.
So has the cut-and-paste editing model that Larry Tesler developed,
first for the Gypsy text editor he wrote at PARC and later
for Apple. Charles Irby – who worked on Xerox’s windows
and is now vice president of development at Metaphor Computer
Systems Inc., Mountain View, Calif. – noted, however,
that cut-and-paste worked better for pure text-editing than for
moving graphic objects from one application to another.
Pop, pull, and tear
Menus – functions continuously listed onscreen that could
be called into action with key combinations – were commonly
used in defense computing by the 1960s. But it was only with
the advent of BitBlt and windows that menus could be made to
appear as needed and to disappear after use. Combined with a
pointing device to indicate a user’s selection, they are now
an integral part of the user-friendly interface: users no longer
need to refer to manuals or memorize available options.
|More than two million of the Apple Macintosh, which brought the graphical user interface to personal computers, have been sold. |
Instead, the choices can be called up at a moment’s notice
whenever needed. And menu design has evolved. Some new systems use
nested hierarchies of menus; others offer different menu versions –
one with the most commonly used commands for novices, another with all
available commands for the experienced user.
Among the first to test menus on demand was PARC researcher
William Newman, in a program called Markup. Hard on his heels,
the Smalltalk group built in pop-up menus that appeared on
screen at the cursor site when the user pressed one of the mouse buttons.
Implementation was on the whole straightforward, recalled
Deutsch. The one exception was determining whether the menu or
the application should keep track of the information temporarily obscured by
the menu. In the Smalltalk 76 version, the popup menu saved
and restored the screen bits it overwrote. But in today’s
multitasking systems, that would not work, because an application
may change those bits without the menu’s knowledge. Such
systems add another layer to the operating system: a display
manager that tracks what is written where.
The production Xerox Star, in 1981, featured a further advance:
a menu bar, essentially a row of words indicating available menus
that could be popped up for each window. Human factors engineer
Verplank recalled that the bar was at first located at the
bottom of its window. But the Star team found users were more
likely to associate a bar with the window below it, so it
was moved to the top of its window.
Apple simplified things in its Lisa and Macintosh with a single bar
placed at the top of the screen. This menu bar relates only
to the window in use: the menus could be “pulled down”
from the bar, to appear below it. Designer William D. Atkinson
received a patent (assigned to Apple Computer) in August 1984 for this
One new addition that most user interface pioneers consider an
advantage is the tear-off menu, which the user can move to
a convenient spot on the screen and “pin” there,
always visible for ready access.
Many windowing interfaces now offer command-key or keyboard
alternatives for many commands as well. This return to the
earliest of user interfaces – key combinations – neatly
supplements menus, providing both ease of use for novices and
for the less experienced, and speed for those who can type faster
than they can point to a menu and click on a selection.
Sketchpad had on-screen graphic objects that represented constraints
(for example, a rule that lines be the same length), and the Flex
machine built in 1967 at the University of Utah by students Alan Kay
and Ed Cheadle had squares that represented programs and data (like
today’s computer “folders”). Early work on icons
was also done by Bell Northern Research, Ottawa, Canada, stemming
from efforts to replace the recently legislated bilingual signs with
graphic symbols. But the concept of the computer “icon”
was not formalized until 1975.
|Much of [Apple Macintosh’s] application software is inconsistent, however: at least three different icons can represent address files. The icons are found in Desktop Express from Dow Jones & Co.; HyperCard from Apple Computer Inc.; and MS Word from Microsoft Corp.|
David Canfield Smith, a computer science graduate student at
Stanford University in California, began work on his Ph.D. thesis
in 1973. His advisor was PARC’s Kay, who suggested that he
look at using the graphics power of the experimental Alto not
just to display text, but rather to help people program.
Smith took the term icon from the Russian Orthodox church, where
an icon is more than an image, because it embodies properties of
what it represents: a Russian icon of a saint is holy and is to
be venerated. Smith’s computer icons contained all the properties
of the programs and data represented, and therefore could be
linked or acted on as if they were the real thing.
After receiving his Ph.D. in 1975, Smith joined Xerox in 1976 to
work on Star development. The first thing he did, he said,
was to recast his concept of icons in office terms. “I looked
around my office and saw papers, folders, file cabinets, a
telephone, and book shelves, and it was an easy translation
to icons,” he said.
Xerox researchers developed, tested, and revised icons for the Star
interface for three years before the first version was complete.
At first they attempted to make the icons look like a detailed
photographic rendering of the object, recalled Irby, who worked
on testing and refining the Xerox windows. Trading off
label space, legibility, and the number of icons that fit
on the screen, they decided to constrain icons to a 1-inch (2.5-centimeter)
square of 64 by 64 pixels, or 512 eight-bit bytes.
Then, Verplank recalls, they discovered that because of a background
pattern based on two-pixel dots, the right hand side of the icons
appeared jagged. So they increased the width of the icons to 65
pixels, despite an outcry from programmers who liked the neat
16-bit breakdown. But the increase stuck, Verplank said, because
they had already decided to store 72 bits per side to allow
for white space around each icon.
After settling on a size for the icons, the Star developers
tested four sets developed by two graphic designers and two software
engineers. They discovered that, for example, resizing may
cause problems. They shrunk the icon for a person – a head
and shoulders – in order to use several of them to
represent a group, only to hear one test subject say the screen
resolution made the reduced icon look like a cross above
a tombstone. Computer graphics artist Norm Cox, now of Cox
& Hall, Dallas, Texas, was finally hired to redesign the icons.
Icon designers today still wrestle with the need to make
icons adaptable to the many different system configurations offered by
computer makers. Artist Karen Elliott, who has designed icons for
Microsoft, Apple, Hewlett-Packard Co., and others, noted that on
different systems an icon may be displayed in different colors,
several resolutions, and a variety of gray shades, and it may
also be inverted (light and dark areas reversed).
In the past few years, another concern has been added to
icon designers’ tasks: internationalization. Icons designed in
the United States often lack space for translations into languages
other than English. Elliott therefore tries to leave space for both
the longer words and the vertical orientation of some languages.
The main rule is to make icons simple, clean, and easily
recognizable. Discarded objects are placed in a trash can on
the Macintosh. On the NeXT Computer System, from NeXT Inc.,
Palo Alto, Calif. – the company formed by Apple cofounder
Steven Jobs after he left Apple – they are dumped into a Black Hole.
Elliott sees NeXT’s black hole as one of the best icons
ever designed – “It is distinct; its roundness stands out
from the other, square icons, and this is important on a crowded
display. It fits my image of information being sucked away, and
it makes it clear that dumping something is serious.”
English disagrees vehemently. The black hole “is fundamentally
wrong,” he said. “You can dig paper out of a wastebasket,
but you can’t dig it out of a black hole.” Another critic
called the black hole familiar only to “computer nerds who read
mostly science fiction and comics,” not to general users.
With the introduction of the Xerox Star in June 1981, the graphical user
interface, as it is known today, arrived on the market. Though not a
commercial triumph, the Star generated great interest among computer
users, as the Alto before it had within the universe of computer designers.
Even before the Star was introduced, Jobs, then still at Apple, had visited
Xerox PARC in November 1979 and asked the Smalltalk researchers dozens of
questions about the Alto’s internal design. He later recruited Larry
Tesler from Xerox to design the user interface of the Apple Lisa.
With the Lisa and then the Macintosh, introduced in January 1983 and January
1984 respectively, the graphical user interface reached the low-cost,
high-volume computer market.
At almost $10 000, buyers deemed the Lisa too expensive for the
office market. But aided by prizewinning advertising and its lower price,
the Macintosh took the world by storm. Early Macs had only 128K bytes of
RAM, which made them slow to respond because it was too little memory for heavy
graphic manipulation, Also, the time needed for programmers to learn its
Toolbox of graphics routines delayed application packages until well into
1985. But the Mac’s ease of use was indisputable, and it generated
interest that spilled over into the MS-DOS world of IBM Pcs and clones, as
well as Unix-based workstations.
Into the courts
The widespread acceptance of such interfaces, however, has led to bitter
lawsuits to establish exactly who owns what. So far, none of several
litigious companies has definitively established that it owns the software
that implements windows, icons, or early versions of menus. But the suits continue.
|Today more than a dozen separate graphical user interfaces run on a variety
of personal computers and workstations. The Presentation Manager component
of Operating System/2 (top), jointly developed by Microsoft Corp. and IBM
Corp., is intended to run on several million IBM and compatible personal
computers; this display shows that too many onscreen windows can impede
clarity. The monochrome NextStep interface (middle) for the NeXT Computer System
from NeXT Inc. offers gray-scale images, but so far no color capability. And
the Open Software Foundation’s Motif (bottom), is the graphical interface for
a new version of the Unix operating system developed by the consortium
of 150 companies that want to keep Unix an open standard. The first commercial
version is to be released in July 1990.|
Virtually all the companies that make and sell either wheel or ball mice
paid license fees to SRI or to Xerox for their patents. Engelbart recalled
that SRI patent attorneys inspected all the early work on the interface,
but understood only hardware. After looking at developments like the
implementation of windows, they told him that none of it was patentable.
At Xerox, the Star development team proposed 12 patents having to do
with the user interface. The company’s patent committee rejected all
but two on hardware – one on BitBlt, the other on the Star
architecture. At the time, Charles Irby said, it was a good decision.
Patenting required full disclosure, and no precedents then existed for winning
software patent suits.
The most recent and most publicized suit was filed in March 1988, by
Apple, against both Microsoft and Hewlett-Packard Co., Palo Alto, Calif. Apple
alleges that HP’s New Wave interface, requiring version 2.03 of
Microsoft’s Windows program, embodies the copyrighted “audio visual
computer display” of the Macintosh without permission; that the
displays of Windows 2.03 are illegal copies of the Mac’s audio
visual works; and that Windows 2.03 also exceeds the rights granted
in a November 1985 agreement in which Microsoft acknowledged that the displays
in Windows 1.0 were derivatives of those in Apple’s Lisa and Mac.
In March 1989, U.S. District Judge William W. Schwarzer ruled Microsoft had
exceeded the bounds of its license in creating Windows 2.03. Then in
July 1989 Schwarzer ruled that all but 11 of the 260 items that Apple cited
in its suit were, in fact, acceptable under the 1985 agreement. The
larger issue – whether Apple’s copyrights are valid, and whether
Microsoft and HP infringed on them – will not now be examined until 1990.
Among those 11 are overlapping windows and movable icons.
According to Pamela Samuelson, a noted software intellectual-property expert
and visiting professor at Emory University Law School, Atlanta, Ga., many
experts would regard both as functional features of an interface that cannot
be copyrighted, rather than “expressions” of an idea protectable by copyright.
But lawyers for Apple – and for other companies that have filed
lawsuits to protect the “look and feel” of their screen displays –
maintain that if such protection is not granted, companies will lose
the economic incentive to market technological innovations. How is Apple
to protect its investment in developing the Lisa and Macintosh, they
argue, if it cannot license its innovations to companies that want to
take advantage of them?
If the Apple-Microsoft case does go to trial on the copyright issues, Samuelson
said, the court may have to consider whether Apple can assert copyright
protection for overlapping windows – an interface feature on which
patents have also been granted. In April 1989, for example, Quarterdeck
Office Systems Inc., Santa Monica, Calif., received a patent for a
multiple windowing system in its Desq system software, introduced in 1984.
Adding fuel to the legal fire, Xerox said in May 1989 it would ask for
license fees from companies that use the graphical user interface. But
it is unclear whether Xerox has an adequate claim to either copyright or
patent protection for the early graphical interface work done at PARC.
Xerox did obtain design patents on later icons, noted human factors engineer
Verplank. Meanwhile, both Metaphor and Sun Microsystems have negotiated
licenses with Xerox for their own interfaces.
To probe further
The September 1989 IEEE Computer contains an article, The Xerox
‘Star’: A Retrospective, by Jeff Johnson et al., covering development
of the Star. Designing the Star User Interface, by David C. Smith et al.
appeared in the April 1982 issue of Byte. The Sept. 12, 1989, PC Magazine
contains six articles on graphical user interfaces for personal computers and
workstations. The July 1989 Byte includes
A Guide to [Graphical User Interfaces], by Frank Hayes and Nick
Baran, which describes 12 current interfaces for workstations and
personal computers. “The Interface of Tomorrow, Today,” by Howard Reingold, in
the July 10, 1989, InfoWorld does the same. “The interface that
launched a thousand imitations,” by Richard Rawles, in the March 21,
1989, MacWeek covers the Macintosh interface.
The human factors of user interface design are discussed in The
Psychology of Everyday Things, by Donald A. Norman (Basic Books Inc., New
York, 1988). The January 1989 IEEE Software contains several articles
on methods, techniques, and tools for designing and implementing graphical
interfaces. How Things Work, by David Macaulay (Houghton Mifflin
Co., Boston, 1988), contains a detailed drawing of a ball mouse.
The October 1985 IEEE Spectrum covered Xerox
PARC’s history in “Research at Xerox PARC: a founder’s
assessment,” by George Pake (pp. 54-61) and “Inside the
PARC: the ‘information architects,’” by Tekla Perry
and Paul Wallich (pp. 62-75).
William Atkinson received patent no. 4 464 652 for the pulldown menu
system on Aug. 8, 1984, and assigned it to Apple. Gary Pope received patent
no. 4 823 108, for an improved system for displaying images
in “windows” on a computer screen, on April 18, 1989, and
assigned it to Quarterdeck Office Systems.
The wheel mouse patent, no. 3 541 541, “X-Y position indicator
for a display system,” was issued to Douglas Engelbart on Nov. 17, 1970,
and assigned to SRI International. The ball mouse patent, no. 3 835 464,
was issued to Ronald Rider on Sept. 10, 1974, and assigned to Xerox.
The first selection device tests to include a mouse are covered in
“Display-Selection Techniques for Text Manipulation,” by William
English, Douglas Engelbart, and Melvyn Berman, in IEEE Transactions on
Human Factors in Electronics, March 1967.
Sketchpad: A Man-Machine Graphical Communication System, by Ivan E.
Sutherland (Garland Publishing Inc., New York City and London, 1980), reprints
his 1963 Ph.D. thesis.