Unit - 1 : Introduction to Computers || BSc CSIT || BIM || BCA || Tribhuvan University - IIT Notes

1. Introduction to Computer

A computer is an electronic, programmable machine that accepts data, processes it, stores it, and displays meaningful information. It follows instructions called programs.

Basic Terms

• Data: Raw facts and figures.
• Information: Processed and meaningful data.
• Hardware: Physical parts of a computer.
• Software: Program that runs the hardware.
• User: Person who operates the computer.

IPO Cycle

1. Input
2. Processing
3. Output
4. Storage

2. Digital and Analog Computers

Digital Computers

They work with discrete values (0s and 1s) and provide accurate results.

Examples: Laptop, desktop, calculator, smartphone.

Analog Computers

They work with continuous data such as temperature, pressure, or speed.

Examples: Speedometer, thermometer, voltmeter.

Hybrid Computers

Combination of both digital and analog computers.

3. Characteristics of Computer

• Speed
• Accuracy
• Automation
• Storage Capacity
• Diligence
• Versatility
• Reliability
• Cost Effectiveness

4. History of Computers

Mechanical Era

• Abacus
• Napier’s Bones
• Slide Rule
• Pascal’s Calculator
• Leibniz Calculator
• Charles Babbage – Father of Computer

Electromechanical Era

Mark-I computer developed using relays.

Electronic Era

Development of electronic components started modern computing.

5. Generations of Computers

First Generation (Vacuum Tubes)

Examples: ENIAC, UNIVAC-1.

Second Generation (Transistors)

Examples: IBM 1401, IBM 7090.

Third Generation (Integrated Circuits)

Examples: IBM 360 series.

Fourth Generation (Microprocessors)

Examples: Personal computers, laptops.

Fifth Generation (AI & Quantum)

Focus on AI, NLP, robotics.

6. Classification of Computers

Based on Size

• Microcomputer
• Minicomputer
• Mainframe
• Supercomputer

Based on Purpose

• General Purpose Computers
• Special Purpose Computers

Based on Data Handling

• Digital
• Analog
• Hybrid

7. The Computer System

Hardware

Physical components such as CPU, keyboard, monitor.

Software

• System Software
• Application Software
• Programming Software

People, Procedures, Data, Connectivity

All elements work together to form a complete system.

8. Applications of Computers

• Education
• Business
• Banking
• Healthcare
• Science & Research
• Government
• Communication
• Entertainment
• Industry
• Transportation