Unit 2.8
Computers Past and Present: A Brief History
IT 231: IT and Application
Learning Objectives
By the end of this session, you will be able to:
- ✅ Name some early calculating devices that preceded modern computers.
- ✅ Describe the key characteristics of first-generation computers.
- ✅ Understand the major technological advancements that led to modern computers.
From Counting to Calculating
The idea of 'computing' is ancient. Long before electronic devices, humans created tools to help with calculations.
The Abacus (c. 2700 BC)
One of the earliest known calculating tools, used for basic arithmetic across ancient civilizations.
Pascaline (1642)
Invented by Blaise Pascal, this gear-driven device was one of the first mechanical calculators.
The Visionary: Charles Babbage
In the 1800s, Charles Babbage designed machines that were conceptual precursors to modern computers.
Difference Engine
A mechanical calculator designed to tabulate polynomial functions automatically.
Analytical Engine
A more ambitious, general-purpose computing machine that could be programmed with punched cards.
🔍 The Analytical Engine is considered a direct precursor to the modern computer because it had a form of memory (the "store") and a processor (the "mill").
The Electronic Era: Computer Generations
The history of modern electronic computers is categorized into "generations," each defined by a major technological breakthrough that fundamentally changed how they were built and operated.
Let's explore the first four generations...
First Generation (1940s-1950s)
Core Technology: Vacuum Tubes
These electronic components controlled current flow. Think of them as large, fragile light bulbs.
Key Characteristics
- ⚡ Massive in size (filled entire rooms)
- ⚡ Consumed enormous amounts of power
- ⚡ Unreliable and generated intense heat
- ⚡ Example: ENIAC
Second Generation (1950s-1960s)
Core Technology: Transistors
A semiconductor device that replaced the bulky vacuum tube. A revolutionary invention.
Key Advancements
- ✔️ Smaller and faster
- ✔️ More reliable and energy-efficient
- ✔️ Cheaper to produce
- ✔️ Computers became more common in business
Third Generation (1960s-1970s)
Core Technology: Integrated Circuits (ICs)
Placed many transistors, resistors, and capacitors onto a single tiny silicon chip.
Impact of Miniaturization
- ✔️ Drastically increased speed and efficiency
- ✔️ Allowed for even smaller machines (minicomputers)
- ✔️ Keyboards and monitors were introduced
Fourth Generation (1970s-Present)
Core Technology: Microprocessors
An entire Central Processing Unit (CPU) on a single integrated circuit. The brain of the computer.
The Personal Computer (PC) Revolution
- ✔️ Made computers small and cheap enough for homes
- ✔️ Led to the creation of Apple and IBM PCs
- ✔️ Foundation of all modern computing devices
Today & The Fifth Generation
The fourth generation continues, but we are entering a new era focused on intelligence.
Fifth Generation: Artificial Intelligence (AI)
The focus is on creating devices that can learn, reason, and interact with the world in more human-like ways.
- Modern computing is defined by mobile devices, the internet, and cloud computing.
- AI is being integrated into everything from smartphones to data analysis.
Practical Application: Computing in Nepal 🇳🇵
The Journey of IT in Nepal
- 1970s: The Mainframe Era
The first computer, an IBM 1401, was brought for the 1971 census. The National Computer Center (NCC) was established with larger mainframes for government data processing.
- 1990s: The PC Revolution
Personal computers became more common in businesses and homes. Computer institutes emerged in Kathmandu, training a new generation in programming and applications.
- 2000s-Today: The Connectivity Era
Widespread internet and mobile adoption has fueled a digital boom, leading to successful fintech (eSewa, Khalti), ride-sharing apps, and a growing software export industry.
🎯 Key Takeaways
- Charles Babbage's Analytical Engine was a key conceptual precursor to modern computers.
- The four main generations are defined by their core technology: vacuum tubes, transistors, integrated circuits, and microprocessors.
- The invention of the microprocessor ushered in the age of the personal computer (PC).
- The current and future generations of computing are increasingly focused on Artificial Intelligence (AI).