Computer Generations: Third, Fourth, and Fifth

Period: $1964 - 1970$
Advancements: Computers became even more advanced and significantly smaller, reducing to the size of a small filing cabinet.
Core Component: The Integrated Circuit (IC) chip.
- Capacity: Held thousands, and eventually millions, of transistors (circuits) on a single chip.
- Inventors: Jack Kilby (an employee of Texas Instruments) and Robert Noyce (an employee of Fairchild Corporation).
- Impact: Due to the high number of transistors per chip, computer power and speed increased while development costs decreased, making computers less expensive overall.

Vacuum Tubes: Slow.
Transistors: Much simpler, much smaller, much cheaper, more reliable, no warm-up time, and much faster than vacuum tubes.
Integrated Circuits: Added miniaturization to all existing benefits of transistors, enabling previously unthought-of possibilities.

More reliable and cheaper than their predecessors.
Less expensive for consumers.
Increased accuracy in calculations and operations.
Increased commercial use due to greater affordability and multi-purpose capabilities.
Smaller in size compared to the previous generation.
Input Devices: Introduction of the keyboard and mouse for input.
Programming: Introduction of high-level programming languages, allowing programming using English words and the base ten number system.
Used a fan to keep the machine cool and disperse heat, leading to faster speeds and calculations.
Required less energy compared to earlier generations.

Very few disadvantages existed for the third generation as they represented the most advanced computers created up to that point.
Primary Challenge: The need to create and mass-produce large numbers of high-level Integrated Circuit chips.

Period: $1971 - \text{Present}$
Physical Evolution: Computers no longer filled entire rooms and did not require huge air conditioners.
Main Electronic Component: The microprocessor chip.
Inventor: Ted Hoff (an employee at Intel).
Microprocessor Capacity: Contained hundreds to thousands of integrated circuits.
Integration Terminology:
- Large Scale Integration (LSI): The ability to hold hundreds of components on a single chip.
- Ultra Scale Integration: The ability to fit millions of components onto a single chip.
Microprocessor Capability: Had the ability to perform all the processing of a full-scale computer.
Initial Development: Initially developed for use in a calculator.
Impact: The placement of millions of transistors on a single chip led to a significant increase in speed, performance, and calculation capabilities.
Result: This small yet powerful chip resulted in the development of personal computers (PCs).
Commercial Availability: In the $1970s$ , personal computers became more affordable, leading people to begin purchasing them.
First PCs:
- Altair $8800$ computer kit: Available for purchase in $1975$
- Apple II: Sold to the public for the first time in $1977$
Networking: Since fourth-generation computers were smaller and more powerful, they could be linked together to form networks, which resulted in the development of the Internet.

Smaller in size compared to previous generations.
More powerful processing capabilities.
More reliable than predecessors.
Cheaper than all other previous generations.
Consumed less power and generated less heat.
Faster processing capabilities.
Totally general-purpose functionality.
High-level languages were used for programming.
Emergence of portable computers.
Development of various types of secondary memory with greater storage capacity and quicker access.
Development of the mouse and handheld devices.

Period: Present and beyond.
Basis: Artificial Intelligence (AI) serves as the foundation for devices and computers developed in this generation.
Primary Goal: To create devices capable of responding to natural language input (e.g., voice recognition).

Robotics: Designed to develop robots that can be programmed to follow instructions and autonomously decide how a task should be executed.
Advanced Control Systems: Used to control the route of a missile and provide warnings for impending attacks.
Language Processing: Devices possess the ability to understand and translate from one natural language to another.
Human-Computer Interaction: This technology enables humans to communicate with computers using everyday language.
Environmental Responsiveness: Devices can respond to their environment through the use of sensors.
- Sensor Applications: Sensors can be used to determine humidity levels, temperature, and detect sound and movement.

Siri: The virtual assistant found on Apple devices is a prime example of fifth-generation computing technology. Users can give Siri commands or ask questions like "How will the weather be tomorrow?" and she will respond.