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Microsoft’s latest product is likely to become the industry standard for
advanced user interface.
Reprinted from PC World, issue 1/1984, pp. 58-61.
Microsoft Windows made quite a stir when it was announced at COMDEX
in Las Vegas last November. The program runs popular software using windows and
mice and was demonstrated simultaneously by more than a dozen vendors.
Windows and mice have recently become very popular topics in the personal computer
industry. Windows because they allow computers to present information in a way that
closely resembles the way people work, and mice because they are the best device
yet devised for converting human instructions to computer actions. Windows and
mice are both the result of research done at Xerox Corporation’s Palo
Alto Research Center during the early ‘70s.
Mice are technically known as “pointing devices,” because they are
used to move the cursor and point to locations on the screen. A mouse is
generally about the size of a deck of cards, fits comfortably in one hand,
and is designed to rest on the table next to the computer keyboard. When you move
the mouse, it sends information to the computer to indicate direction and distance, which the
computer translates into cursor movements on the screen. You can point to any
location on the screen by moving the mouse around on the table. Most mice have one to
three buttons that you can push to execute frequently used commands.
Mice have been available for several years, but their use is not widespread,
probably because most popular programs are not designed to take advantage of them.
Consumers won’t buy mice unless programs use them, and software companies don’t
want to write the programs unless consumers have mice. Further compounding the problem is
the fact that there is no standard way to connect a mouse to a computer.
Some mice plug into a serial port, some plug into a game paddle port, and others require
a special interface card. Also, different brands of mice send different signals to indicate
direction and distance.
Windows have been used for many years. If you have used WordStar or have programmed in
BASIC on the IBM PC, you have already seen windows in action. WordStar uses separate
windows to display command menus and text, and BASIC uses a one-line window at
the bottom of the screen to display the values assigned to the function
keys. A window is an area of the screen that operates independently
from the rest of the screen.
Many spreadsheet programs let users define windows to separate information
displayed on the screen. One limitation with these windows is that they can display
only information generated by the spreadsheet program. There is no way, for example,
to divide the screen into two windows and then use one window to
run a separate word processing program.
VisiCorp offers the Visi/ON system as a standard software interface
that can be used to operate a variety of programs in a mouse and window
environment. Visi/ON provides true window capabilities that enable users
to define different areas of the screen for each program, but it also has
several drawbacks. Programs must be specially written to use Visi/ON, and
the software interface is very complex, requiring a major investment for software companies.
Visi/ON is also expensive. In addition to its $495 price, the system requires
a hard disk drive and at least 256K memory.
Microsoft Windows
The ideal mouse and window system would be inexpensive, would
work with off-the-shelf programs, and it would require a minimal
amount of disk storage and memory. That is a good description of
Microsoft Windows. It works with most off-the-shelf software, requires
only two floppy disk drives and 192K of memory, and is intended to be
sold at low-cost or included with DOS when buy a computer. The
product is scheduled for release in April.
Microsoft Windows is an extension of MS-DOS, providing a standard interface
to the mouse and the screen in the same way that MS-DOS itself
provides a standard interface to disk drives and other devices.
Microsoft divides programs that will work with Microsoft Windows into
three categories. In the first category are programs that use standard
MS-DOS functions to perform all input and output. These programs work
well with Microsoft Windows and can share the display with similar programs.
The second type are those that perform their own screen operations. Most
spreadsheet programs fall into this category because the MS-DOS screen
functions are too slow to provide the fast changes in the screen display
necessary for good performance. Microsoft Windows can recognize
these programs and allows them to use the entire screen until they
terminate.
In the third category are programs that have been designed to operate in
conjunction with Microsoft Windows. Such programs are portable; the
same program can be run on two different machines and can make the
best use of each machine’s capabilities. Microsoft Windows automatically
compensates for the differences. These programs also benefit from
Microsoft Windows’ extensive library of special functions such as the ability
to pass data between windows.
Functional Description
 |  Figure 1: Overlapping windows of a typical window management system |
Unlike other window management systems, Microsoft Windows does not
have overlapping windows. Instead, it uses a technique called tiling, which
arranges windows to fill the screen completely and make the best use of the
screen display area. Figure 1
shows three overlapping windows,
and Figure 2 shows how tiling arranges three windows to prevent
overlap. According to Microsoft Windows Product Manager Scott
McGregor, research has shown that
most users prefer to have windows arranged neatly. Microsoft Windows’
tiling feature does this automatically, arranging two windows so that each
takes up one-half of the screen, or three windows so that each occupies
one-third. Of course, the user can change the size and position of any
window. Microsoft Windows simply makes a guess at correct placement.
 | | Figure 2: Windows tiled to prevent overlap |
Windows in Microsoft Windows are normally composed of four parts,
as shown in Figure 3. At the top is the caption, which shows the name of the
program or file using the window. Below the caption is an optional
menu area and below that the window display area. Finally, there are
horizontal and vertical scroll bars. Scroll bars allow the user to visualize
which portion of the data can be seen through the window. Moving the
scroll bars with the mouse changes the contents of the window.
 | | Figure 3: Typical window as displayed by Microsoft Windows |
At the left and right edges of the caption are icons, symbolic representations of
functions that Microsoft Windows can perform. To execute a function you
simply move the mouse to position the cursor over the icon and then
press a button. Icons are much easier to use than typed commands, and
they convey information more rapidly. Microsoft Windows can change icons
to reflect status graphically. A printer icon, for example, can be flashed on
and off to indicate that the printer is out of paper.
Icons that affect the entire display rather than just one window appear at
the bottom of the screen. A window-specific icon might enlarge a
window to fill the entire screen or move the window to another location.
An icon with a screen-wide effect might open a new window or
prepare the system to be shut down at the end of the day. One Microsoft
Windows feature reduces an entire window to an icon that is then displayed
at the bottom of the screen. Selecting the icon restores the window
to its original form.
In short, Microsoft Windows provides a simple, powerful, and inexpensive
user interface that works with most popular programs. That alone is enough to
guarantee consumer support to make it the de facto standard of the personal computer
market.
Hardware manufacturers will also benefit because Microsoft Windows
uses installable device drivers for the mouse and the video display. Manufacturers
will be able to provide a device driver without concern for the
programs that the buyer will be using. A manufacturer of a high-resolution
color graphics interface, for example, will need to provide a driver that
reflects only the display capabilities. All the programs written to use
Microsoft Windows will automatically adjust to the higher resolution.
Widespread use of Microsoft Windows will have many long-term benefits
for the entire personal computer industry. Microsoft Windows insulates
programs from the actual mouse and screen hardware, which means
that advances in technology are realized as consumer products much
more rapidly. Software companies will need to sell only one version of a
program; the Microsoft Windows interface for any particular machine
will be written by the hardware manufacturer.
Technical Notes
Microsoft intends to modify all their programming languages to support
Microsoft Windows, and as it gains popularity, you can expect to see
more programs designed to take advantage of its special features.
One special feature allows an application program to “register interest”
in another program’s data. Microsoft Windows will inform the
first program whenever the data changes. A graphics program, for example,
can use this feature to draw a new graph whenever data from a
spreadsheet program changes.
Microsoft Windows has a datapassing protocol that allows programs
to exchange data in the most efficient manner. Some programs can
exchange data in the form of text only; others can support binary data or
other protocols that have been defined by the computer industry. Microsoft
Windows determines the highest protocol the programs have in
common and then uses that protocol to pass data between them.
It provides those features passively; that is, it gives programs
access to a variety of data concerning the display but does not require them
to use or acknowledge that information. Thus, Microsoft
Windows maintains compatibility with currently available
software.
Although Microsoft representatives refused to discuss DOS 3.00,
they did indicate that Microsoft Windows has been designed to take advantage
of the multitasking abilities of that prospective operating system.
Under DOS 2.00, you may display several windows, but only one window
is active at a time. Multitasking will allow users to run several programs
simultaneously; for example, a communications program can run in
one window while a word processing program is used in another.
Microsoft Windows should have a lasting effect on the entire personal
computer industry. It frees hardware manufacturers to concentrate their
efforts on producing the best possible product without regard for maintaining
compatibility with any other machine. For software authors it means
that programs can be sold to a much wider market, because differences
among computers will no longer require time-consuming modifications.
For the consumer, Microsoft Windows provides tremendous flexibility
in the selection and use of personal computers.
Steven Cook
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