Lesson Notes By Weeks and Term - Junior Secondary School 2

SUBJECT: ICT

CLASS:  JSS 2

DATE:

TERM: 1st TERM

 
WEEK ONE

TOPIC: CLASSIFICATION OF COMPUTER BASE ON SIZE

Computer is classified base on size as follows:

1. Supercomputer
2. Mainframe computer
3. Mini-computer
4. Micro-computer

1. Supercomputers:
   supercomputers are widely used in scientific applications such as aerodynamic design simulation, processing of geological data.
   
   • Supercomputers are the most powerful computers. They are used for problems requiring complex calculations.
   • Because of their size and expense, supercomputers are relatively rare.
   • Supercomputers are used by universities, government agencies, and large businesses.

1.  Mainframe Computers: 
   mainframe computers are usually slower, less powerful and less expensive than supercomputers. A technique that allows many people at terminals, to access the same computer at one time is called time sharing. Mainframes are used by banks and many business to update inventory etc.
   • Mainframe computers can support hundreds or thousands of users, handling massive amounts of input, output, and storage.
   • Mainframe computers are used in large organizations where many users need access to shared data and programs.
   • Mainframes are also used as e-commerce servers, handling transactions over the Internet.

1.  Minicomputers: 
   Minicomputers are smaller than mainframe, general purpose computers, and give computing power without adding the prohibitive expenses associated with larger systems. It is generally easier to use.
   • Minicomputers usually have multiple terminals.
   • Minicomputers may be used as network servers and Internet servers.

1. Microcomputers or Personal Computers:
   Microcomputer or personal computer is the smallest, least expensive of all the computers. Micro computers have smallest memory and less power, are physically smaller and permit fewer peripherals to be attached.
   • Microcomputers are more commonly known as personal computers. The term “PC” is applied to IBM-PCs or compatible computers.
   • Desktop computers are the most common type of PC.
   • Notebook (laptop) computers are used by people who need the power of a desktop system, but also portability.
   Personal Computers (PC): Desktop, Laptop, Palmtop and PDA