Overview
This lecture outlines the evolution of computer hardware from vacuum tubes to modern microprocessors, explaining key components like transistors, logic gates, integrated circuits, and the five generations of computers.
Vacuum Tubes and Transistors
- Vacuum tubes (valves) were early electronic components used as switches in first-generation computers.
- Transistors, made from conductors, insulators, and semiconductors, replaced vacuum tubes due to smaller size and higher efficiency.
- A transistor has three pins (collector, emitter, base) and acts as a switch controlled by current at the base.
Logic Gates and Integrated Circuits
- Logic gates are basic circuits created by combining transistors to perform logic operations using binary (on/off) signals.
- Integrated circuits (chips or microchips) group many transistors on a single piece of semiconductor, allowing complex circuits in smaller, faster devices.
- More complex integrated circuits include adders for binary calculation and flip-flops for memory.
Microprocessors
- A microprocessor is a CPU on a single integrated circuit, processing binary data based on instructions.
- Microprocessors are multipurpose, clock-driven, register-based digital circuits that receive, process, and output binary data.
Generations of Computers
- 1st Generation: Used vacuum tubes, were large, expensive, and programmed with machine code; input/output via punch cards and magnetic tape.
- 2nd Generation: Utilized transistors, making computers smaller, cheaper, and more reliable; used assembly and early high-level languages.
- 3rd Generation: Employed integrated circuits, leading to smaller, more efficient computers; programmed with high-level languages.
- 4th Generation: Introduced microprocessors (VLSI technology), driving the PC revolution with affordable, compact computers.
- 5th Generation: Current computers use ULSI technology, fitting millions of components on a chip for high power and efficiency.
Moore's Law
- Moore’s Law states that the number of transistors on a chip doubles about every two years, greatly increasing computing power.
Key Terms & Definitions
- Vacuum Tube (Valve) — early electronic switch used in first-generation computers.
- Transistor — a three-pin electronic switch critical in modern circuits.
- Logic Gate — a circuit that performs basic logic operations on binary inputs.
- Integrated Circuit (Chip) — a small semiconductor with multiple electronic circuits.
- Microprocessor — a CPU contained within a single integrated circuit.
- Moore’s Law — observation that transistor count on chips doubles every two years.
Action Items / Next Steps
- Review examples of logic gates and integrated circuits.
- Explore the list of 7400 series integrated circuits for more on chip types.
- Study the evolution of programming languages across computer generations.