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This new technology makes controlling your computer easier than ever
Reprinted from Personal Computing, issue 3/1983, pp. 102-105. Part 3 of the
article “New from Apple: Lisa and the IIe.”
Electronic mice like the ones used to control cursor movement on Apple’s Lisa
computers bear a striking resemblance to real mice in more ways than you might imagine.
Not only do they fit neatly into the palm of your hand, have long skinny tails, and move
as nimbly around your desk as real mice might, but to meet the demand for their use on
personal computers, electronic mice may soon be multiplying at a rate that would more than rival
their furry cousins.
About the size and shape of a package of cigarettes, the electronic mouse is a plastic box
with wheels and a 2-foot-long wire tail that plugs into your microcomputer. When you roll this
clever little fellow around on your desk, it sends electronic signals back through its tail
to move the screen’s blinking cursor or pointer in direct proportion to its own movement. On top,
the mouse has one or more buttons that let you edit text, select from menus, transport items across
the screen, or do a number of tasks that so far seems limited only by the imaginations of
software designers.
Furthermore, if industry predictions prove correct, our now relatively unknown electronic friend may
well proliferate at an astounding rate. In fact, Jack Hawley, the developer and builder of perhaps
80 percent of the mice in use today, estimates that “by 1985, at least one third and
possibly over one half of all computer work stations including personal computers will feature
mice,” The “big cheese” of mouse builders also points out that over 60
companies, including the heavyweights of the mainframe and personal computer industries, have
bought mice to evaluate or to
offer with their existing or future systems. Moveover, the introduction of Lisa’s mouse may
force other personal computer firms to follow suit even more rapidly. Why all the excitement
over a little mouse? To put it simply, the mouse is a versatile cursor-mover that helps make a
computer vastly easier and faster to use. For instance, if you’ve ever edited text for
even a short time, you know how painstakingly slow it is to use arrow keys to move the
cursor a line or a space at a time. With a mouse, on the other hand, you can move the cursor
to any point on the screen virtually as fast as you can point with your finger. Then, depending
on how the software is set up, you click the button or buttons on top to delete, move, save,
scroll, or otherwise manipulate text.
But perhaps the biggest advantage is for executives, engineers, and professionals who wish to make
menu selections, review information, and develop reports or graphics. Typically not skilled
typists, such users are not particularly comfortable or efficient at the keyboard and find the
mouse much more friendly. Moreover, Stuart Card, a researcher in human/computer interaction at
the Xerox Palo Alto Research Center (PARC), points out that the coming of age of interface
graphics (split-screen displays, windows, pictures, and so forth) means the time is ripe
for a pointing device with the mouse’s capabilities.
You can even draw with a mouse, but not nearly well enough to do detailed work or trace drawings the
way you can with a graphics tablet. “Drawing with a mouse is like drawing with
a rock” says Card, But the mouse is the perfect tool for picking up symbols,
words, sentences, and so forth and carrying them to other locations in your text or drawings.
Because you don’t need your fingers to precisely position a mouse as you do with a light
pen or joystick, you can click buttons and make alterations with much greater facility. What’s
more, one manufacturer claims that with the proper software a mouse can give you 95 percent of
the capabilities of a graphics tablet for a small fraction of the cost.
Two basic types of mice have now been developed: mechanical and optical. At the time of this
writing, only the mechanical variety is commercially available. These mechanical mice are
surprisingly mature products that have, in a sense, been trapped in research laboratories
waiting forlornly for owners to take them home. Until now they have been used primarily on
larger computer systems such as the Xerox Star 8010 Professional Workstation, the Sun
Workstation, and Symbolics and LMI LISP machines.
Mechanical mice
The first mouse was invented in the 1960s by Douglas Engelbart at the Stanford Research Institute
(SRI) and was patented in 1970. This mouse is a simple, round-edged box that rolls on
two wheels placed at right angles to one another. When you roll it forward, one wheel rotates
freely while the other skids along without turning. When you roll the mouse at an angle,
each wheel turns in direct proportion to the extent of forward or sideways motion. A signal
converter translates wheel motions to electronic signals that the computer can read, and
these let the machine know precisely where the mouse is at all times.
Although revolutionary, this design had its limitations. It used potentiometer-type wheels
that work like the volume dial on your home stereo. When you turn the wheel one way it produces
increasing voltage, and when you turn it the other way it produces decreasing voltage.
This was ideal for tracking the mouse’s location, but the wheels soon wore out and
were big and noisy. (How many people would have been interested in a mouse that roared across
their desks?) Besides that, the analog-to-digital signal converter was prohibitively expensive
and the software quite complex.
In 1972, Hawley developed for Xerox a digital mouse that used simpler software and didn’t
need those old-fashioned potentiometers or expensive analog-to-digital signal
converters. In 1975, he was again commissioned by Xerox to improve on a mouse invented
by Willard Opocensky that rolls on stainless-steel ball bearings and eliminates the drag
of sideslipping wheels. What he came up with was an extremely popular mouse that has been
used by the thousands at Xerox and at research establishments cooperating with Xerox.
Following Hawley’s design, Xerox began producing the mouse for its Star in 1981. Hawley
himself obtained a license under Xerox and SRI patents to sell the Hawley X063X mouse,
now available from the Mouse House in Berkeley, California, for $415.
Hawley’s mouse works on an extremely simple principle (see
illustration, page 103). Shaft encoders
connected to one of the stainless-steel balls translate mechanical
signals to the binary signals computers can read.
Another interesting model is the Depraz mouse developed at the Swiss Federal Institute of
Technology. This hemispherical little fellow works on the same basic principle as Hawley’s
mouse except that it uses an optical-scanning technique to detect mouse motions and
translate them into digital signals. Inside these mice, scanners detect tiny lights shining
through equally spaced windows in the thin wheels that pick up x and y motions. In this
sense, Swiss mice (their preferred style of cheese is unknown) are a kind of hybrid between
the mechanical and optical mice: tracking is done mechanically and encoding is done
optically. Pierluigi Zappacosta, vice-president of Logitech Inc. in Palo Alto, California,
the U.S. supplier of Swiss mice, claims that this method of encoding eliminates static and
is less sensitive to dust and dirt than the methods used on other types of mechanical
mice. The Swiss mouse sells for $295.
Product Associates of Redwood City, California, markets a less expensive mechanical mouse based
on the original Engelbart design. This model features an analog-to-digital converter,
potentiometer-type wheels, and an RS-232C interface. Martin Hardy, president of Product
Associates, says that the mouse uses an integrated analog-to-digital converter and improved
potentiometer wheels featuring a roller-bearing design that is smaller, quieter, and more
durable than those used on the first mouse. Hardy says the mouse sells for $149.
Optical mice
The optical mouse works on an entirely different principle. As it glides on its felt,
Teflon, or slick plastic base over a special tablet marked with an array of dots or a
grid of lines, the optical mouse compares the images it “sees” before and after
any movement. By looking at changes in the images of the dots or lines that it traverses, the
mouse can tell precisely how far and in what direction it has moved.
Mechanical-mouse proponents claim that the special grid used by some optical mice is a
limitation in that it locks users into an uncomfortable position at their desks. This type
of optical mouse must at all times be properly aligned with the grid, a concern
not felt by users of mechanical mice or optical mice that read an array of dots.
Responding to such criticism, Steve Kirsch, president of Mouse Systems Corporation in
Sunnyvale, California, claims that in fact most mechanical mice require a special surface
to achieve reliable tracking. Kirsch also reports that his optical mouse, which should be
available by the time you read this, sports several features that make it superior to
mechanical mice, including precise tracking with no moving parts, greater reliability, and
a more compact design. The list price for Kirsch’s optical mouse is estimated
at $286, and it is scheduled to be available with interface cards for the IBM Personal
Computer and the Apple II. These cards will cost $51 each, and an RS-232C interface
box will sell for $26.
What to expect
Random Access Inc. of Pittsburg, Pennsylvania, also offers a mouse interface for the
Hawley and other compatible mice. A parallel interface for Apple, IBM, or S-100-based computers or
a serial interface for computers with an RS-232C port is available for $295. Richard Wolf,
design engineer at Random Access, is optimistic about the future of mice. What
we should expect to see soon from software firms, he says, are word-processing,
spreadsheet, CAD/CAM (computer-aided design/computer-aided manufacturing), graphics, and other
programs that will take full advantage of the mouse.
Even with updated software, though, just adding a mouse won’t give you the features
of Apple’s Lisa, with its 16-bit microprocessor, high-resolution graphics, and integrated
software. But if enough companies follow Apple’s lead, we may well see a mouse
population explosion and the introduction of an odd assortment of mouse accessories with an
even odder assortment of names.
by Phil Lopiccola
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