Generation of computer

1.First generation of computer
The main features of first generation of computer are:-

• Vacuum tube technology
• Unreliable
• Supported machine language only
• Very costly
• Generated lot of heat
• Slow input and output devices
• Huge size
• Need of A.C.
• Non-portable
• Consumed lot of electricity

Some computers of this generation were:-

• ENIAC
• EDVAC
• UNIVAC
• IBM-701
• IBM-650

2.Second generation of computer
The main features of second generation of computer are:-

• Use of transistors
• Reliable in comparison to first generation of computers
• Smaller size as compared to first generation of computers
• Generated less heat ascompared to first generation of computers
• Consumed less electricity as compared to first generation of computers
• Faster than first generation computers
• Still very costly
• A.C. needed
• Supported machine and assembly languages

Some computers of this generation were:-

• IBM 1620
• IBM 7094
• CDC 1604
• CDC 3600
• UNIVAC 1108

3.Third generation of computer
The main features of third generation of computer are:-

• IC used
• More reliable in comparison to previous two generations
• Smaller size
• Generated less heat
• Faster
• Lesser maintenance
• Still costly
• A.C. needed
• Consumed lesser electricity
• Supported high-level language

Some computers of this generation were:-

• IBM-360 series
• Honeywell-6000 series
• PDP(Personal Data Processor)
• IBM-370/168
• TDC-316

4.Fourth generation of computer
The main features of fourth generation of computer are:-

• VLSI technology used
• Very cheap
• Portable and reliable
• Use of PC's
• Very small size
• Pipeline processing
• No A.C. needed
• Concept of internet was introduced
• Great developments in the fields of networks
• Computers became easily available

Some computers of this generation were:-

• DEC 10
• STAR 1000
• PDP 11
• CRAY-1(Super Computer)
• CRAY-X-MP(Super Computer)

5.Fifth generation of computer
The main features of fifth generation of computer are:-

• ULSI technology
• Development of true artificial intelligence
• Development of natural language processing
• Advancement in parallel processing
• Advancement in superconductor technology
• More user friendly interfaces with multimedia features
• Availability of very powerful and compact computers at cheaper rates

Some computers of this generation are:-

• Desktop
• Laptop
• Notebook
• Ultrabook
• Chromebook

Q.Define algorithm and state properties of it?
Algorithm is a finite set of instructions that,if followed accomplishes a particular task.

Algorithm should satisfy the following criteria:-
1.Input:Zero or more quantities are externally supplied.
2.Output:At least one quantity is produced.
3.Definiteness:Each instruction is clear and unambiguous.Ex.:Add B or C to A.
4.Finiteness:Algorithm should terminate after finite number of steps when traced in all cases.Ex.:Go on adding elements to an array.
5.Effectiveness:Every instruction must be basic i.e.,it can be carried out,by a person using pencil and paper

Algorithm must also be general to deal with any situation.