History of Computers

Charles Babbage is the father of computer, because the parts and working principle of the Analytic Engine, which is invented by him is similar to today‘s computer.

Evolution of Computer

1. Abacus
2. Astrolabe
3. Pascaline
4. Stepped Reckoner
5. Difference Engine
6. Analytical Engine
7. Punch Cards
8. ENIAC (Electrical Numerical Integrator and Calculator)
9. Von Neumann Machine

Generations of Computers with Features

The computer can be classified into four generations according to their type of electronic devices such as Vacuum Tube, Transistor, IC etc.

The First Generation Computers (1949-55)

Main Features:

• The computers of this generation used vacuum tubes.
• These computers used machine language for giving instructions.     
• They used the concept of stored program.
• These computers were 5000 times faster than the MARK-I.
• The first generation computers were welcomed by Government and Universities.

Limitations:

• These computers were very big in size. The ENIAC machine (Electronic Numerical Integrator and Calculator) was 30 x 50 feet in size and 30 tons in weight. So, these machines required very large space for their workings.
• Their power consumption was very high.
• These computers had slow operating speed and small computing capacity.     
• These computers had a very small memory.

The Second Generation Computers (1956-65)

Main Features:

• The computers of this generation replaced vacuum tubes with transistors.    
• Magnetic cores were invented for storage.
• Different magnetic storage devices were developed in this generation.
• Commercial applications were developed during this period. Eighty present of these computers were used in business and industries.

Third Generation Computers (1966-75)

Main Features:

• The third generation computers replaced transistors with ‗Integrated Circuits. These Integrated Circuits are also known as chips.
• The size of main memory was increased and reached about 4 megabytes.
• Magnetic disk technology had been improved and drive having capacity up to 100 MBPS came into existence.
• The  CPU  becomes  more  powerful  with  the  capacity  of  carrying  out  1  million instructions per second.
• This generation computers were relatively inexpensive and faster.
• The  application  area  also  increased  in  this  generation.  For  example,  areas  like education, small businesses, and analysis along with previous usage areas.

The Fourth Generation Computers (1976-Present)

Main Features:

• The  fourth  generation  computers  replaced  Small  Scale  Integrated  circuits  and Medium Scale Integrated circuits with the Microprocessors chip.     Semiconductor memories replaced Magnetic Core memories.
• The  hard-disks  are  available  of  the  sizes  up  to  200 GB. The  RAID  technology (Redundant Array of Inexpensive Disks) gives storage up to thousands of GB.     
• Computer cost came down rapidly in this generation.
• Application of computers is increased in various areas like visualization, parallel computing, multimedia etc.

The Fifth Generation Computers

Mankind along with the advancement in science and technology is working hard to bring the Fifth Generation of computer. These computers will have the capability of thinking on their own like a man with the help of Artificial Intelligence (AI). The 21st  century will be better, faster, smaller and smarter computers.

Electronic Components Used for Different Computer Generations:

Generations	Electronic Components
First Generation	Vacuum tubes
Second Generation	Transistors
Third Generation	Integrated Circuits
Fourth Generation	Microprocessors
Fifth Generation	Artificial Intelligence

Languages Used in Computer Generations

Generations	Languages used
First Generation	Machine Language
Second Generation	Assemble Language, Mnemonics
Third Generation	High   Level   Language,   BASIC,   PASCAL,   COBOL, FORTRON
Fourth Generation	4th Generation Languages
Fifth Generation	Artificial Intelligence

Expand COBOL, BASIC, FORTRON and IBM

•  COBOL – Common Business Oriented Language

•  BASIC - Beginner‘s All Purpose Symbolic Instruction Code

•  FORTRON – Formula Translation

•  IBM – International Business Machine

Expand IC, SSI, MSI, LSI, and VLSI

•  IC – Integrated Circuit.

•  SSI - Small Scale Integration.

•  MSI - Medium Scale Integration.

•  LSI - Large Scale Integration.

•  VLSI - Very Large Scale Integration.

http://currentaffairs2you.blogspot.com/