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graphical user
interfaces. Where IBM-compatible personal computers’ console
terminals were text oriented, Apple, beginning first with the Lisa machines and
then the Macintosh machines, provided a graphical display screen coupled first
to a keyboard for user-program information interchange. Then, with the
inclusion of a mouse, it introduced the first widely distributed truly
point-and-click interaction style between users and computer programs. In fact,
it was a mutation implementing earlier ideas developed at Xerox that resulted
in all computers growing profound extensions to the sensori-motor experience
through which they interacted with people. Of course, just as in any
evolutionary mix, existent species had to react to the changed environment or
perish.
MS-DOS, the
primary initial offering on IBM
compatible personal computers was almost a throwback to what we discussed above
as the primitive operating systems of the earliest large-scale computers. It
assumed complete control of the computer platform on behalf of a single user
who had access to all the input/output facilities of the computer; actually,
access to the entire sensori-motor system of the computer. Given how far this
concept was from the operating systems of the mainframe and minicomputer lines
of the times, it is not surprising that IBM and Microsoft set out to collaborate on
a more powerful operating system for personal computers. The target development
was called OS/2.
This
collaborative effort between IBM
and Microsoft sought to provide a multi-tasking operating system for IBM personal computers; in effect, a
replacement operating system for MS-DOS. While the system was completed and
introduced after some fits and starts, in an interesting marketing end-run,
Microsoft preempted the deployment of OS/2 with the introduction of its own,
proprietary personal computer operating system that it called Windows. Windows
was a close relative to MS-DOS while OS/2 claimed closer relationship to the
mainframe operating systems. The similarly timed release of both Windows and
OS/2 was one of the more startling episodes in the intermingling of market
driven versus technology driven forces thus far seen in the world of computers.
Both systems were, in effect, responses to the mutational advances made by
Apple in the form and style of man-machine interactions.
Based on both mainframes
with largely IBM operating systems and mini-computers
running UNIX or UNIX-like operating systems, the late 1980’s and the 1990’s saw
the development of Internet-based computing. This largely took the form of
client-server architectures with the afore-mentioned mainframes and
mini-computers forming the server components, and Windows or Mac based personal
computers forming the client components. Windows continued to stress ease of
propagation over security and consequently continued to suffer a wide range of
attacks, some of which were disastrous to large segments of the computer
network environment worldwide. Obviously, this presented a market opportunity
for the right type of software.
Developed during
the early 1990’s by Sun Microsystems, Java was introduced as a portable
computing environment with applicability ranging from distributed Web
applications to individual, hand-held devices. Its true claim to fame, however,
was its provision of a high degree of security for software that was intended
to operate on arbitrary platforms across the full range of the Internet. Java
provided this high security capability by offering a highly constrained
sensori-motor system.
Following the
historical perspective that we noted previously, the architectural picture for
large-scale computer systems that we have thus far painted presents a view of
multi-user and multi-application systems that may be found on a variety of
computer platforms. Such systems offer the power and convenience of varying
contexts allowing for extremely wide-ranging interactions between human users
and sensori-motor extensions. Information across the full spectrum of
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Bertrand du Castel 
Timothy M. Jurgensen