Types Of Computers

 

Computers are classified on the following two basis

1.   Based upon the speed
2.   Based upon the computation

Based upon the speed :-

Based upon the speed computers are classified in to 4 types

1. Super Computers 
2. Main frame Computers 
3. Mini Computers 
4. Micro Computers

1. Super Computer

 It is very fast and used for scientific applications. 

Uses :

• scientific simulations
•  animated graphics 
• analysis of geological data
• nuclear energy research and meteorology
•  computational fluid dynamics

2. Main frame Computer

It is a large general purpose computer and it is used to store large amount of data. 

Uses :

•  support hundreds or thousands of users, 
•   handling huge amounts of input, output, and storage.
•   It is used in large organizations to share data and programs between many users.
•   It is used as e-commerce servers
•   It is used to handle transactions over the Internet. 

3. Mini Computer-

   It is smaller than main frame computer and bigger than micro computer. It have multiple terminals. 

 Uses : 

•  Minicomputers may be used as network servers and Internet servers. 

4. Micro Computer-

It is commonly known as Personnel computer.

 Uses: 

• It can be used for single applications as well as multiple applications. 

Advantages / Uses of computer

The uses of computer are listed below :

• Word processing 

• Data processing and statistical analysis 

• Storage and retrieval device (medical records) 

• Communication device (E-mail, telephone, internet Websites) 

• Processing device for images, graphics and sounds. 

• Teaching device. 

• Medical diagnosis (Tele-radiology) 

• Prescriptions. 

GENERATIONS OF COMPUTER 

The evolution of modern computer is divided in to 5 generations.

1.   First generation (1942 -1958)
2.   Second generation (1959-1965)
3.   Third generation (1966-1975) 
4. Fourth generation (1976-1989)
5.   Fifth Generation (1989 Present and Beyond)

1.. First generation Computer :-

• In First generation Vaccum tubes were used as a component. 
• It used punched cards as input device, and it uses magnetic tapes and magnetic drums as secondary memory.
•  It uses Binary code or machine language for programming. 
• Only one programmer can access at same time 

        Ex. ENIAC, EDVAC

Disadvantages 

•  Too large in size
•  Unreliable  generated heat due to vacuum tubes 
•  Air conditioning required 
•  Frequent hardware failure 
•  Constant maintenance required 
•  Non-portable 
•  Very Expensive

 Advantages 

 It is used for Record keeping and payroll processing

2. Second Generation Computers 

• In Second generation Transistor were used as a component.
•  Transistor is an electronic device which consists of base, emitter and conductor.
•  It is mainly used for updating files and payroll processing. 

       Ex. PDP - 1

Advantages : 

•  Smaller size 
•  Less heat generation 
•  Less power consumption 
•  Less prompt to hardware failure 
• Faster 
•   Portable
•   Computational time reduced to milliseconds to micro seconds. 

Disadvantages : 

•  Air conditioning required 
•  Constant maintenance required
•   More Expensive

3. Third generation Computer-

In third generation Integrated Chip(IC) were used as a component. It replaces 1000 transistors = 1 IC. It is used for airline reservations, credit cards, billings. Ex. IBM – 360 

Advantages : 

• Smaller size 
• Less heat generation 
• Less power consumption
•  Less prompt to hardware failure 
•  Faster 
•   Portable
•   Computational time reduced to micro seconds to nano seconds.
•  Production is easier and cheaper

 Disadvantages :

•   High technology is required to manufacture IC. 
•  It requires temperature control. 

4. Fourth generation Computer-

In fourth generation VLSI(Very Large Scale Integration) were used as a component. It replaces 1million components = 1 single chip. This technology is known as VLSI.

 

Ex. IBM PC – INTEL 8088

• Advantages:  Smaller size 
•  Less heat generation 
•  Less power consumption 
•  Less prompt to hardware failure 
•  Faster 
•  Portable 
• Computational time reduced to micro seconds to nano seconds. 
•  Production is easier and cheaper  No A/C required 

5. Fifth generation Computer-

In fifth generation Artificial Intelligence is used for making “Expert Systems” which can perform task as much intelligence as human beings. 

  Ex: ROBOT

• Advantages :
•   Performance is equal to human expert 
•  It provide alternate solutions to a problem.