Unformatted text preview: in 1956, EDVAC was still a carousal machine
with 4,000 vacuum tubes and 10,000 crystal diodes.
Although most of these activities were taking place in USA, there were
other efforts in other countries. For example, around the time EDVAC
was being developed, there was an experiment at the University of
Manchester in the United Kingdom also based on the stored program
By 1948, the Manchester team had produced a machine working with
32 words of memory and a 5-instruction set.
Still in England, at Cambridge University, the electronic delay storage
automatic calculator- EDSAC was produced in 1949.
Across the Atlantic in 1948, the universal automatic computer –
UNIVAC I, became the first commercially available computer. From that point, the general purpose computer took on a
momentum of its own. They become bigger and more
powerful. Companies sprang up both in US and Europe to
manufacture these wonder machines. Among the leaders
were: International Business Machines (IBM), Honeywell,
and Control Data Corporation (CDC) in the USA, and
International Computers Limited, (ICL) in UK.
These companies and a number of others, built what
came to be known as the mainframe, huge computers
that consisted of a 4 to 5 feet by 8 feet tape drives, a huge
control processing unit, a huge printer, several huge fixed
disks, a large card reader and a paper punch.
These components usually filled a large room or two.
Because these computers were big, expensive, and
difficult to use – computers users could only use the
computers through a computer operator.
The computer operator fed jobs to the computer via a
card or tape reader. The jobs were submitted to the card
reader as decks of punched cards.
Because of the fact that these computers were big,
expensive and difficult to use, only large companies and Around mid to late sixties, a movement to make computers less
expensive and more affordable started gathering momentum.
This movement led to a number of developments. First it led to the
manufacture of a less expensive but smaller computer – the medium
range computer commonly referred to as minicomputer.
Secondly, it started a mode of computing that later led to
networking. This was the timesharing, where, one computer could
be used by a number of users who would remotely connect on to
Third and most important, it led to a milestone in the history of
computing. This milestone occurred between 1971 and 1976. This
was the development of the first microprocessor.
A microprocessor is an integrated circuit with many transistors on a
single board. Before the birth of the microprocessor, computer
technology had developed to a point that vacuum tubes and diodes
were no longer used.
Computers were now constructed from thousands of transistors.
The demand for more powerful computers, necessitated the
development of computers with many thousands of transistors.
But it was not possible at the time to simply pack m...
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- Fall '12
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