Wednesday, January 18, 2012

Types of Computers:Mainframe, Mini, Workstation,Supercomputers, Personal computers, Personal, Micro-controller, Server,


EMainframe computers:
§Are large-sized, powerful multi-user computers that can support concurrent programs.
§That means, they can perform different actions or ‘processes’ at the same time.
§Mainframe computers can be used by as many as hundreds or thousands of users at the same time.
§Large organizations may use a mainframe computer to execute large-scale processes such as processing the organization's payroll.
Mainframe computers
§Examples: IBM’s ES000, VAX 8000 and CDC 6600.
E  Mini-Computers:
   §Are mid-sized multi-processing computers.
   §Again, they can perform several actions at the same time and can support from 4 to 200 users simultaneously.
 §In recent years the distinction between mini-computers and small mainframes has become blurred.
   §Often the distinction depends upon how the manufacturer wants to market its machines.
  § Organizations may use a mini-computer for such tasks as managing the information in a small financial system or maintaining a small database of information about registrations or applications.
   §  Examples: PDP 11, VAX 7500, IBM(8000 series).

EWorkstation:
§Are powerful, single-user computers.
§They have the capacity to store and process large quantities of data, but they are only used by one person at a time.
§However, workstations are typically linked together to form a computer network
§called a local area network, which means that several people, such as staff in an office, can communicate with each other and share electronic files and data.
workstation
§A workstation is similar to a personal computer but is more powerful and often comes with a higher-quality monitor.
§In terms of computing power, workstations lie in between personal computers and mini-computers.
§Workstations commonly support applications that require relatively high-quality graphics capabilities and a lot of memory, such as desktop publishing, software development and engineering applications.

Personal computers:

(PCs), also called microcomputers, are the most popular type of computer in use today.
The PC is a small-sized, relatively inexpensive computer designed for an individual user.
Today, the world of PCs is basically divided between IBM-compatible and Macintosh-compatible machines, named after the two computer manufacturers.
Computers may be called ‘desktop’ computers, which stay on the desk, or ‘laptop’ computers, which are lightweight and portable.


Personal computer

Organizations and individuals use PCs for a wide range of tasks, including word processing, accounting, desktop publishing, preparation and delivery of presentations, organization of spreadsheets and database management.
Supercomputers:

§Supercomputers are fast because they are really many computers working together.
§Supercomputers were introduced in the 1960's as the world's most advanced computer.
§These computers were used for complex calculations such as forecasting weather and quantum physics.
§Today, supercomputers are one of a kind; they are fast and very advanced.
SuperComputer
§The term supercomputer is always evolving as tomorrow's normal computers are today's supercomputer

§Examples: CRAY-3, Cyber 205 and PARAM.
Microcontroller: 

§Microcontrollers are mini computers that enable the user to store data, do simple commands and tasks, with little or no user interaction with the processor.
§These single circuit devices have minimal memory and program length but can be integrated with other processors for more complex functionality.
§Many such systems are known as Embedded Systems. Examples of embedded systems include Smart phones or car safety systems.
§Microcontrollers are important, they are used everyday in devices such as appliances and automobiles.
Server:


§Similar to mainframes in that they serve many uses with the main difference that the users (called clients) do their own processing usually.
§The server processes are devoted to sharing files and managing log on rights.
§A server is a central computer that contains collections of data and programs. Also called a network server, this system allows all connected users to share and store electronic data and applications.
§Two important types of servers are file servers and application servers.