Generation of
Computers
The history
of computer development is often in reference to the different generations of
computing devices. Each of the five generations of computer is characterized by
a major technological development that fundamentally changed the way computers
operate. Most developments resulted in increasingly smaller, cheaper, more
powerful & more efficient computing devices. Generation of computers is
mainly classified by 5 different generations. These are:
1)
First Generation Computers(1949-55) :
The 1st generation emerged during 1949 & lasted till 1955.
The 1st large electronic computer was ENIAC which used high speed
vacuum tubes & was invented in 1946. It was mainly designed to calculate
the trajectories of missiles. It took about 200 ms to perform addition &
about 2800 ms to perform multiplication. Later on, EDSAC was developed in 1949
which used mercury delay lines for storage. Also, UNIVAC 1 was designed during
this period, which also used vacuum tubes. Generally, these computers used more
than 10,000 tubes & so, power dissipation was very high. These were mainly
used in the field of science & engineering. Programming was mainly done in
machine language. The concept of operating system wasn’t introduced yet. In
this generation punched cards, paper tapes & magnetic tapes were used as
input & output devices. The
computers in this generation were very costly & not within the reach of
common people. Also, they were quite bulky which made them non-portable.
2)
Second Generation computers(1956-65)
The 2nd generation evolved during 1956 & lasted till 1965.
This generation witnessed a revolution in electronics world by introduction of
transistors instead of previously used vacuum tubes. Transistors were more
reliable & they took very less space than tubes. During this period,
magnetic cores were developed for storage. Also, magnetic disk storage was
invented. High level programming languages like COBOL, FORTRAN etc. were
developed. With higher speed CPUs, magnetic tapes etc., the operating systems were
developed (Good Batch OS). The 2ndgeneration computers consumed less
electricity & generated less heat in comparison to 1st
generation computers. Also, they were faster & cheaper than 1st
generation computers. Commercial applications were improved during this
generation. The 2ndgeneration computers supported machine &
assembly language. 80% of installed computers were in business & industry.
This generation also paved the way for new professions like system analyst,
programmers etc. Some computers of this generation were IBM 1620, IBM 7094,
UNIVAC 1108 etc.
3)
Third generation computers(1966-75):
This generation emerged during 1966 & lasted till 1975. This
generation witnessed the introduction of silicon transistors instead of
previously used germanium transistors. Integrated circuits(IC’s), which
consisted of resistors, transistors & capacitor came into existence. From
small scale IC’s, consisting of 10 transistors per chip, it developed to medium
scale IC’s which contained 100 transistors per chip. Thus, reliability &
switching speed went up by a factor of 10 and space & power dissipation was
reduced by a factor of 10. These all led to the emergence of extremely powerful
CPUs which could carry about 1 million instructions per second. Programming
languages were improved. High level languages like FORTRAN II to IV, COBOL,
PASCAL, BASIC etc. were used during this generation. Also, a new operating
system, known as Time-Sharing OS came into existence. The 3rdgeneration
computers needed lesser maintenance, consumed less electricity, generated less
heat, were smaller in size & cheaper than previous generation computers.
Some computers of this generation were IBM-360 series, Honeywell-6000 series,
PDP etc.
4)
Fourth Generation computers:
This generation emerged during 1976 & lasted till 2000. This
generation witnessed introduction of microprocessor chips. From middle scale
IC’s, the technology developed to large & very large scale IC’s (VLSI),
which consisted of about 50,000 transistors per chip. It led to emergence of
extremely powerful PCs. Cost of computers went down rapidly. It was now within
the reach of every professional. Cost of hard disks also went down & high
capacity secondary storage was introduced. It saw the coming age of UNIX OS
& Time-Shared interactive systems which were more reliable & user
friendly. There was a relentless increase in the speed of microprocessors &
size of main memory, which increased by a factor of 4, every 3 years. Also, DVD
ROMs & writable CDs were developed. A large no. of computers got connected
with Internet, due to which WWW (World Wide Web) came into existence. It
resulted into emergence of Object Oriented language called JAVA. Later on, C,
C++ was also developed. Now, the computers were within reach of common people
too. Some computers of this generation were DEC 10, STAR 1000, PDP 11 etc.
5)
Fifth Generation computers:
The 5th generation has revolutionized whole world of digital
electronics. It has paced up the development of computers. There has been a
relentless increase in the no. of transistors on a single chip. This generation
witnesses a rapid increase in the bandwidth of network & consequently,
Internet. It offers mobility to its users & provides them a good multimedia
experience. It is mainly concerned with Parallel processing hardware & Artificial
Intelligence (AI). In 5thgeneration
VLSI became ULSI (Ultra Large Scale Integration), which results in the
production of microprocessor chips having 10 million electronic components. AI
(Artificial Intelligence) is an emerging branch, which interprets means &
method of making computers think like human beings. All high level-languages
like C & C++, JAVA, .NET etc. are used in this generation. This generation
is witnessing development of natural language processing, advancement in
parallel processing, advancement in superconductor technology & so many
other technological advancements in all the fields. It provides more
user-friendly interface with multimedia features. More powerful & compact
computers are available at cheaper rates. Some computers of this generation are
Laptop, PCs, Notebook etc.
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