# Lesson Notes By Weeks and Term - Senior Secondary 1

Classification of computers II

Term: 1st Term

Week: 6

Class: Senior Secondary School 1

Age: 15 years

Duration: 40 minutes of 2 periods each

Date:

Subject:      Data Processing

Topic:-       Classification of Computers II

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Discuss the classification of computers based on the size

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers, demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, pictures, Data Processing for senior Secondary Education by Hiit Plc, WAPB Computer Studies for Senior Secondary I by Adekunle et al, On-line Materials.

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

 PRESENTATION TEACHER’S ACTIVITY STUDENT’S ACTIVITY STEP 1 INTRODUCTION The teacher reviews the previous lesson on the classification of computers based on their type and functionality Students pay attention STEP 2 EXPLANATION He discusses the classification of computers based on their size; super computers and mainframe computers Students pay attention and participates STEP 3 DEMONSTRATION He discusses further the classification of computers based on their size; mini computers and micro computers Students pay attention and participate STEP 4 NOTE TAKING The teacher writes a summarized note on the board The students copy the note in their books

NOTE

CLASSIFICATION OF COMPUTERS

Computers can be generally categorized into four, namely

1. Super computers

1. Mainframe computers
2. Mini computers
3. Micro computers

SUPER COMPUTER

These are the largest, fastest and most expensive computers. The cost is several millions of dollars and the speed is between 600 million to 900 million instructions per second (MIP).

Another name for super computer is MONSTER. Scientists in weather forecasting, exploration make use of super computers. It can also be used for complex calculations e.g CRAY, X-MP etc.

MAINFRAME COMPUTERS

A mainframe computer is a large computer in terms of price, size of internal memory and speed. It has a variety of peripheral devices such as printers, plotters etc more than those found with small computers, except small computers with large amount of external storage.

Mainframe computers usually need a specialized environment to operate, with dust, temperature and humidity carefully controlled. They are used in large establishments e.g banks, airports etc. Examples of Mainframe computers are IBM 360/370,NCR-V 8800.

MINI COMPUTERS

Mini computers were developed in the 1970s for specialized tasks (i.e they are special purpose computers).

They are smaller and less powerful and less expensive than mainframes.

Mini computers, as they are called, are easier to install and operate e.g PDP II, VAX 750/6000, NCR 9300, DEC, HP 3000 etc.

MICRO COMPUTERS

A microcomputer is a computer whose central processing unit (CPU) is based on a microprocessor.

Micro computers are at present the most popular of computers. They are very small. The capability is generally not as many and not as complex as mini computers or Mainframe computers. They are easy to use. Another name for microcomputer is Personal Computer (PC).

REASONS WHY MICRO COMPUTERS ARE WIDELY USED

1. They are cheap.
2. They have small sizes.
3. They do not require special environment for their operations.
4. They can be used anywhere.

EVALUATION:    1. What is another name for super computer?

1. Mention TWO examples of mainframe computer.
2. Differentiate between mini and microcomputers.

1. Give two examples of minicomputer.
2. Mainframe computers are used for …….

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively