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Unit 1 – Brief History of Computers

Items In This Unit


  • Important Computer Events
  • The Rise of Transistors
  • Computer Processors (CPUs) and Number of Transistors
  • Video Lecture
  • Assignment
  • Further Research

Important Computer Events

The rise of computers and computing devices dates back to the thirties of the 20th century. When we take a look at the computer history we can observe some of the most important events depicted in the diagram below.

The very first transistor was made in 1947 and was much bigger in size then today’s transistors. As the transistor size shrunk with the advancements in computer technology the computing power grew exponentially.

The Rise of Transistors

The rise of computers and computing devices dates back to the thirties of the 20th century.

In the digital context, a transistor is a binary switch and the fundamental building block of computer circuitry. Like a light switch on the wall, the transistor either prevents or allows current to flow through. A single modern CPU/processor can have hundreds of millions or even billions of transistors. Think of a transistor as an ON / OFF switch and memory (RAM) of the size of 1 bit (1/8 of a byte)! The transistor is the most basic unit of computing It represents 2 states ON or OFF. The ON state represents a numerical value of 1. The OFF state represents a numerical value of 0.

Computer Processors (CPUs) and Number of Transistors

Computer power typically grows with the number of transistors. The following table depicts various generations of computer processors (CPUs).

Processor Year CPU Bits Max Memory # of Transistors
4004 1971 4 640B 2,300
8008 1972 8 16KB 2,500
8080 1974 8 64KB 4,500
8086 1978 16 1MB 29,000
Intel286 1982 16 16MB 134,000
Intel386™ Processor 1985 32 4GB 275,000
Intel486™ Processor 1989 32 4GB 1,200,000
Intel® Pentium® Processor 1993 32 64GB 3,100,000
Intel® Pentium® II Processor 1997 64 64TB 7,500,000
Intel® Pentium® III Processor 1999 32 64GB 9,500,000
Intel® Pentium® 4 Processor 2000 64 64TB 42,000,000
Intel® Itanium® Processor 2001 64 18EB 25,000,000
Intel® Itanium® 2 Processor 2003 64 18EB 220,000,000
…and so on

Video Lecture

To learn more about transistors, please watch this amazing video by Gokul J. Krishnan titled “How transistors work”.

Assignment: Enhance your knowledge

  • Watch the following video and answer the question below:
    • What was the name of the first ever video game?
  • Search on Google or DuckDuckGo when the first “Floppy Disk” or “Floppy Drive” was made?
    • What was the purpose of the Floppy Disk?

Further Research & References

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