Unit 1.1
Introduction to Computers
IT 231: IT and Application
🎯 Learning Objectives
By the end of this session, you will be able to:
- ✅ Define what a computer is and its fundamental process.
- ✅ Differentiate between digital and analog computers.
- ✅ List the key characteristics of a modern computer.
- ✅ Briefly describe the history and generations of computers.
What is a Computer?
An electronic device that processes data and performs tasks according to a set of instructions.
At its core, everything a computer does follows a simple, powerful cycle:
Input
➔
Process
➔
Output
This is the Input-Process-Output (IPO) model, the foundation of all computing.
Analog vs. Digital Computers
Computers are classified based on how they represent data.
Analog Computers 🌡️
- Process continuous, variable data.
- Measure physical quantities.
- Examples: A traditional mercury thermometer, a car's speedometer, a voltmeter.
Digital Computers 💻
- Process discrete data in binary format (0s and 1s).
- Perform logical and arithmetic operations.
- Examples: Laptops, smartphones, smartwatches, calculators.
Practical Application: Computers in Nepal
You use digital computers every day, often without thinking about it!
📱 Digital Payments
Using eSewa or Khalti to pay a utility bill is a perfect IPO example: You input the details, the app processes the payment, and you get a confirmation output.
🚌 Smart Public Transport
The digital ticketing systems used in some Kathmandu Valley buses are small, dedicated computers that process fares and track passenger data.
Key Characteristics of a Computer
What makes modern digital computers so powerful?
⚡ Speed
Performs billions of calculations per second. Far beyond human capability.
✅ Accuracy
Calculations are extremely precise. Errors are almost always due to human input or programming flaws.
⚙️ Diligence
Never gets tired or bored. Can perform repetitive tasks for hours with the same accuracy.
Key Characteristics (Continued)
🔄 Versatility
A single machine can be used for entertainment, scientific research, design, and communication.
💾 Storage Capacity
Can store vast amounts of data in a tiny physical space and retrieve it almost instantly.
Combined: These characteristics are why computers have revolutionized every aspect of modern life.
A Brief History: The Five Generations
The evolution of computers is marked by major technological shifts.
- 1st Gen (1940s-50s): Vacuum Tubes. Enormous, expensive, and unreliable machines that filled entire rooms.
- 2nd Gen (1950s-60s): Transistors. Replaced vacuum tubes, making computers smaller, faster, cheaper, and more reliable.
- 3rd Gen (1960s-70s): Integrated Circuits (ICs). Placed many transistors on a single silicon chip, drastically reducing size and cost.
- 4th Gen (1970s-Present): Microprocessors. An entire CPU on a single chip. This led to the Personal Computer (PC) revolution.
- 5th Gen (Present & Beyond): Artificial Intelligence (AI). Focuses on parallel processing and creating machines that can learn and reason.
The Game Changer: The Microprocessor
The Microprocessor (4th Gen) is arguably the most significant invention in computing history. It contains thousands or millions of Integrated Circuits on a single tiny chip.
How did it change the world?
- It made the Personal Computer (PC) possible and affordable.
- It put computing power into the hands of individuals, not just large organizations.
- It is the "brain" inside your smartphone, car, and countless other smart devices.
🔍 Chapter 1: Key Takeaways
- A computer is a device that follows the Input-Process-Output (IPO) model.
- Digital computers (using 0s and 1s) are the standard today, distinct from older analog computers.
- Core characteristics that make computers powerful are Speed, Accuracy, Diligence, Versatility, and Storage.
- Computer history is defined by generations based on key technology: Vacuum Tubes ➔ Transistors ➔ ICs ➔ Microprocessors ➔ AI.
Discussion & Questions
Think About It...
Which computer characteristic do you think is most important for scientific research? Why?
For Next Time...
Besides a laptop or phone, what is another digital computer you use daily? Be prepared to share.