A computer is a machine or an electronic device that takes input (instructions/data) from you, processes that input, and then gives you output (results). It is composed of several parts:
- Input Devices: Such as the keyboard, mouse, through which you provide data.
- Processing Unit: This is your processor (CPU), which does the real work.
- Storage Devices: Such as RAM and hard drive, where data is stored.
- Output Devices: Such as the monitor, speakers, printer, through which you receive the results.
The Processor (CPU):
The Processor (also called CPU or Central Processing Unit) is a small chip that is called the Brain of the computer. Its main function is to understand, calculate, and complete every instruction given to the computer. When you click a mouse, play a game, or type something, the processor handles all that work.
Main Functions of the Processor:
- Fetch: Takes the instruction from memory.
- Decode: Understands what task needs to be performed.
- Execute: Completes the task by performing arithmetic, logical, and control calculations.
- Writeback: Sends the result back to memory.
The “First Computer”
Which was the “first computer” depends on which definition of a computer you use—whether it was mechanical, programmable, or electronic.
- The Father of Mechanical Computers: Charles Babbage
Charles Babbage is widely regarded as the “Father of the Computer.”
- Difference Engine:
- Time and Contribution: 1820s. It was an automatic, mechanical calculator designed to create accurate mathematical tables. It was steam-powered and built to reduce errors.
- Analytical Engine: 1830s, and it was his most important invention. It was the first design that contained all the fundamental parts of today’s computers:
- Mill: Which performed calculations like today’s CPU (Central Processing Unit).
- Store: Which held data like Memory.
- Input/Output: Via Punch Cards.
- It is considered the first General-Purpose computer design, although Babbage could not fully build it in his lifetime.
Ada Lovelace: She wrote notes for Babbage’s Analytical Engine and created an Algorithm. For this reason, she is recognized as the First Computer Programmer in the world.
- The First Electronic Digital Computer: ENIAC (Electronic Numerical Integrator and Computer)
The modern computing era began with electronic computers, and the ENIAC is the most significant in this category. Its construction began in 1943 and was completed in 1945 (publicly announced in 1946). It was the first fully electronic, programmable digital computer. It used Vacuum Tubes for calculation (approximately 18,000). It was 50 feet long, weighed 30 tons, and occupied the space of a large room. It was used by the US Army to calculate artillery firing tables.
The Concept of Program Storage: EDVAC (Electronic Discrete Variable Automatic Computer): After the ENIAC, Mauchly and Eckert worked on the EDVAC with John von Neumann.
- Contribution: EDVAC introduced the concept of the “Stored-Program Architecture,” meaning the computer could store both the program and the data in the same memory. This principle is still the foundation of every modern computer (your laptop or phone) today.
- If you talk about the ‘Father’: it is Charles Babbage.
- If you talk about the ‘First Programmable Electronic Computer’: it was ENIAC.
See this Post in Hindi : कंप्यूटर और प्रोसेसर: एक परिचय
Generations of Computers:
The development of the computer so far has been mainly divided into Five Generations. Each generation represents a major technological leap that completely changed the size, speed, and capability of the computer.
- First Generation (1940s – 1950s)
- Main Technology: Vacuum Tubes
- Characteristics:
- These computers were very large (occupying an entire room).
- They were very slow and generated a lot of Heat.
- Their use was mainly for scientific and engineering calculations.
- Examples: ENIAC, EDVAC, UNIVAC.
- Second Generation (1950s – 1960s)
- Main Technology: Transistors
- Characteristics:
- Transistors were smaller, faster, cheaper, and generated less heat compared to vacuum tubes.
- Computer size decreased and processing speed increased.
- The use of Assembly Language and early High-Level Languages like FORTRAN and COBOL began.
- Examples: IBM 7000 series, CDC 1604.
- Third Generation (1960s – 1970s)
- Main Technology: Integrated Circuits (ICs) or Chips
- Characteristics:
- Many transistors, resistors, and capacitors were packed onto a tiny silicon chip (an IC). This made the speed very fast and reduced the cost.
- Computer size became even smaller (e.g., desktop or mini-computers).
- The use of Operating Systems began, allowing multiple programs to run at the same time.
- Examples: IBM 360 series, DEC PDP-8.
- Fourth Generation (1970s – 2010s)
- Main Technology: Very Large Scale Integration (VLSI) or Microprocessor
- Characteristics:
- Thousands of ICs were fitted onto a single chip, leading to the development of the Microprocessor Chip. This put the computer’s entire Central Processing Unit (CPU) onto one chip.
- This led to the Personal Computer (PC) Revolution.
- The development of the Internet, Graphical User Interface (GUI), and computer networking occurred.
- Examples: IBM PC, Apple Macintosh, computers with Intel Pentium chips.
- Fifth Generation (2010s – Present)
- Main Technology: Artificial Intelligence (AI), Parallel Processing, and ULSI (Ultra Large Scale Integration)
- Characteristics:
- The main goal of this generation is to develop computing systems that can react like the human brain, such as: Artificial Intelligence (AI), Machine Learning (ML), and Deep Learning.
- Use of parallel processing and superconductor technology to increase computer performance.
- Research in Voice Recognition, natural language understanding, and Quantum Computing.
- Examples: Robotics, Neural Networks, Smartphones, and today’s AI-powered systems.
Thus, the computer has gone through five major technological transformations, from vacuum tubes to today’s powerful AI-based systems.
Generations of CPU (Central Processing Unit):
Like computers, the development of the CPU (Central Processing Unit) is also divided into generations, but this division is based on the major changes in the Architecture and design by CPU manufacturing companies like Intel or AMD. Broadly speaking, the CPU’s development is counted from the advent of the first microprocessor in the 1970s, which became the foundation of the fourth generation of computers.
Here is a division of CPU generations based on key technological changes:
Major Generations of Microprocessor CPUs
CPU generations are usually counted based on the following technology:
- First Microprocessor Generation (1970s): 4-bit and 8-bit CPU
- Main Change: Bringing the entire CPU onto a single chip (Microprocessor).
- Characteristics: 4-bit to 8-bit data processing. Very few transistors.
- Examples: Intel 4004 (the first commercial microprocessor in 1971), Intel 8080.
- Second Generation (1970s – 1980s): 16-bit CPU
- Main Change: 16-bit processing, which increased data handling capacity.
- Characteristics: Instrumental in the development of the Personal Computer (PC).
- Examples: Intel 8086, Motorola 68000.
- Third Generation (1980s – 1990s): 32-bit CPU (The x86 Era Begins)
- Main Change: 32-bit Architecture (IA-32), which made modern Operating Systems (like Windows and Mac OS) possible.
- Characteristics: Introduction of Cache Memory, better speed.
- Examples: Intel 80386, Intel 80486, and early Pentium processors.
- Fourth Generation (1990s – 2000s): Pipelining and High-Speed Clock
- Main Change: Complex instruction Pipelining and high Clock Speed (measured in GHz).
- Characteristics: Better capacity to handle multimedia and 3D graphics.
- Examples: Intel Pentium II / III / 4 (NetBurst Architecture).
- Fifth Generation (2000s – 2010s): Multi-Core Revolution
- Main Change: Instead of increasing clock speed, adding more than one processing core (Dual-Core, Quad-Core) onto the same chip.
- Characteristics: 64-bit Architecture (x86-64) became the standard. Focus on reducing power consumption.
- Examples: Intel Core 2 Duo, early Intel Core i-series (i3, i5, i7), AMD Athlon 64.
- Sixth Generation (2010s – Present): Integrated Graphics and Optimization
- Main Change: Integrating the CPU and Graphics Processing Unit (GPU) onto a single chip (APU).
- Characteristics: Better performance per watt, efficient designs for laptops. Continuous architectural improvements in the Intel Core i-Series (e.g., Skylake, Kaby Lake, etc.) and the rise of AMD Ryzen.
- Examples: All current Intel Core i9/i7/i5/i3 and AMD Ryzen processors.
There is no fixed international rule for counting the generations of CPUs. It depends on technological innovation. However, from the first microprocessor (1970s) to today’s multi-core, 64-bit, AI-centric chips, the CPU has gone through approximately six major generations of technological change.
We will learn about the different types of processors in the next post.
