punching machines. Operating staff accepted
jobs through a window and delivered results in
the form of line printer print-outs (and the
returned card decks). During program develop-
ment that typically meant lists of error messages.
The primary task of the operating staff was to
keep the computer in stable and reliable opera-
tion for high productivity, referring to the use of
computer time as an overwhelming cost factor.
Those card decks could be large, sometimes fill-
ing long steel drawers almost too heavy to carry.Electronic integrated circuits and devices for
storage and presentation (semiconductor mem-
ory, storage disks and CRT screens) have gone
through a very comprehensive development
indeed continuously since 1960. Then the first
digital circuits could be built in large scale using
transistors rather than vacuum tubes. That devel-
opment improved performance characteristics
by many orders of magnitude (and continues
rapidly to improve further).From the mid 1970s that technical development
permitted complete programmable computers to
be made cheaply enough to make it meaningful
economically for one person to have the com-
puter alone. The movement of the human per-
son’s fingers and her ability to think and formu-
late commands and questions are very slow if
measured in a computer’s time scale. Looking at
the exploitation of a personal computer – PC –
one will typically find the computer running idle
most of the time while the user thinks or does
something else. The PC-phenomenon – econom-
ically seen – is that it makes economic sense to
have the machine idling, but immediately avail-
able to the user – the person. Unlike the situation
today that was far from true for many years.Resource Sharing Networks
Computers began to have practical significance
in business as tools and production machinery
from the last half of the 1950s. Computer tech-
nology and its use have continued to improve
and increase since then. This technology has an
unbelievably large and increasing importance.
The development has continued and continues
on. All the time it becomes more specialized
and refined.Academic interest in this dramatic development
started in a few places. From the late 1950s it
was the basis of a new industry, rapidly growing.
IBM was the foremost, gigantic, standard setting
“powerhouse” among several great companies.
A large and growing number of engineers and
technical scientists engaged themselves in the
study and development of the great new poten-
tial that they saw and that began to open up
around 1960.One broadly based research program started in
the late 1960s. The Advanced Research Projects
Agency – ARPA – of the United States Depart-
ment of Defense sponsored the building of a
resource-sharing network called Arpanet. It
connected four computers at universities and
research establishments in the western United
States. The research program was basic technical
research and the visions about Arpanet were
resource sharing. Important and valuable re-
sources that could be shared and hence be better
exploited were several: Powerful computers
(although quite weak by today’s measures) were
too expensive to be procured by all those who
wished for them and who could have put them
to good use. It became desirable to make such
computer resources available to more groups
of people. Thereby new problem areas might be
attacked and manifold creativity might more eas-
ily meet in fruitful collaboration – resource shar-
ing.The punched card was an
important input medium well
into the 1970s. It was only
replaced when timesharing
and sufficient disk storage
permitted users to enter their
programs directly and leave
them in the computer. One
card represented up to 80
characters. (Pictures copied
from “Britannica.com”)
By 1970 the integrated circuit
technology had developed to a
point where microprocessors
could be “stamped out”
cheaply on silicon wafers in
large numbers. This picture
shows an experimental wafer
with an array of several
different circuit chips. The
matrix is cut into individual
chips