The fourth generation computers started with the invention of Microprocessor. The microprocessor contains thousands of ICs. Ted Hoff produced the first microprocessor in 1971 for Intel. It was known as Intel 4004. The technology of integrated circuits improved very rapidly. The LSI (Large Scale Integration) circuit and VLSI (Very Large Scale Integration) circuit were designed. It greatly reduced the size of computer. The size of modern microprocessors is usually one square inch. It can contain millions of electronic circuits. The examples of fourth generation computers are Apple Macintosh and IBM PC.

Advantages:

1. More powerful and reliable than previous generations

2. Very small in size

3. Less power consumption and less heat generated

4. Fan for heat discharging and thus to keep cold

5. no air conditioning is required

6. Best speed and calculate data in one billionth per second

7. Less need of repairing

8. Cheapest among all generations

9. Commercial production

10. All types of high-level languages can be used in this type of computers.

Disadvantages:

The latest technology is required for manufacturing microprocessors.