Describe the features of different generation of computers with example.
First Generation Computers:
The First Generation Computers was marked
by the use of vacuum tubes for the electronic components and by the use of
electrostatic tubes or mercury delay lines for storage. Examples of first
generation computers are EDSAC (1949), EDVAC (1951) etc., this generation
lasted until the end of the 1950s and the computers in this era had their basis
in wired circuitry and thermion valves. Their outstanding features were:-
§
Very
expensive, poor reliability, slow input/output.
§
Quite
large, generated lot of heat and required special housing.
§
The
medium of internal storage was magnetic drum.
§
Punched
cards and paper tapes were used for secondary storage.
§
Continuous
maintenance is required; produces lot of heat hence requires special air
conditioning.
§
Applications-pay
roll and other single applications in large companies.
§
Uses
batch processing technology, to process the data.
Examples:
o
In
1949 – at Cambridge University EDSAC (Electronic Delayed Storage Automatic
Calculator was developed).
o
In
1952 at Pennsylvania University, EDVAC (Electronic Discrete Variable Automatic
Calculator) was developed.
o
In
1951, UNIVAC-I (Universal Automatic Computer) was developed.
Second Generation Computers:
The second-generation computers are
initially marked by either magnetic drum or magnetic core storage and later by
the use of the transistor in the place of vacuum tubes.
Main features of the second-generation computers are:
Main features of the second-generation computers are:
§
Magnetic
core was used as primary storage device and tape as secondary storage.
§
Used
transistor circuits, hence the size of the computer was small compared to that
of first generation computer.
§
Greater
reliability and higher speed, when compared to that of first generation
computers.
§
Uses
high level procedural languages viz., FORTRAN (Formula Translator) 1954-57,
COBOL (Common Business Oriented Language) 1957-61.
§
They
are small, faster and required less power to operate.
§
Applications:
Payroll, Inventory, Accounts Receivable, in large and medium sized companies:
Ex: IBM 700, 1401; ATLAS; ICL 1901
Third
Generation Computers (1965-1971):
The arrival of the third generation in the
mid 1960’s proved to be an important milestone in the evolution of computers.
The advances over the previous generations were very significant and allowed an
increased number of organizations to reap the undoubted benefits which
computerization could bring.
The
following are the features of this generation:
§
Further
reductions in size of computer.
§
The
cost/performance factor has improved significantly.
§
Increased
internal core memory capacity.
§
Processor
speeds are rated in nano seconds.
§
The
use of high-level languages became common e.g.: COBOL, FORTRAN and PL/I.
§
Multiprogramming
operating system was developed.
§
Magnetic
disk was used as secondary storage.
§
Transistors
were replaced with integrated circuits – hence increased miniaturization.
§
Computers
were capable of performing both scientific and business tasks with high speed
and reliability.
§
Input
and Output devices are improved.
§
Applications:
Order Processing, air line reservation, real-time inventory control etc.
§
Uses
online, real time processing and multiprogramming operating system.
Ex:
IBM/360/370; NCR 395; Burroughs-B6500.
Fourth Generation Computers:
The fourth generation computers arrived in
mid 1970’s. The distinguishing marks were the introduction of standard
architecture, which proved greater mobility of the system. The introduction of
micro technology and significant software developments, Micro technology gave
rise to the development of microcomputers, work processors and intelligent
terminals.
Features
of this fourth generation are:
§
Integrated
Circuits are replaced with very large-scale integrated circuits.
§
Semiconductors
used as primary storage.
§
Dramatic
decrease in the size of computer – development of microcomputers, personal
computer.
§
Development
of electronic spreadsheet.
§
Development
of database management systems.
§
Development
of distributed databases and virtual storage operating system.
§
Increased
use of data communications and computer networks.
§
Increased
use of Cathode Ray Tube (CRT)
terminals.
§
The
computers are compact, faster, and cheaper and are more reliable.
§
Application:
Corporate modeling, decision support system, electronic funds transfer,
electronic spread sheet, word processing and small business applications.
Future Computers (since 1985):
By the end of 1982, the computers were used
every where, in automobiles, appliances, business information systems, and
military hardware. With electronic technology advancing rapidly, the use of
computers expected to grow in coming years. With the increased user
requirements, the technology has evolved with outstanding features.
Some
of the important features of the future computers are:
§
Future
Computers use organic chips to process the data.
§
Both
the software and hardware costs are decreasing at a high speed, so that the
computers can be used by every common man (within the reach of common man).
§
Increased
miniaturization and price/performance ratio.
§
The
computers have high speed, and storage capacity.
§
Has
the capacity to make decisions. (Auto decisions).
§
Uses
non-procedural software, which is very user friendly.
§
Applications:
Artificial Intelligence, Robots, Large Scale Corporate modeling, oil
exploration, star wars system and personal robots.
This is an open age for computer. Its gaining more and more superpower, being more sophisticated and convenient, and human being is going to be completely dependable on this human developed brain.
KHS
8391
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