Classification of Computers by Generations – Basic 2 Computer Studies Lesson Note (Third Term)

Learning Objectives: By the end of this lesson, pupils should be able to:

• explain first and third generations of computers

Lesson Content:

Classification of Computers by Generations:

What are Computer Generations? Computer generations are different time periods when computers were built with different technologies. Each generation was better than the previous one.

First Generation Computers (1940s-1950s):

Technology Used:

• Vacuum tubes: Large glass bulbs that controlled electricity
• Very big and hot machines
• Used punch cards for input

Characteristics:

• Size: Very large, filled whole rooms
• Weight: Extremely heavy, several tons
• Speed: Very slow compared to today
• Cost: Very expensive, only big companies could afford
• Heat: Generated lots of heat, needed air conditioning

Examples:

• ENIAC: One of the first computers
• UNIVAC: Used for government work
• IBM 701: Used by businesses

Problems:

• Broke down frequently
• Used lots of electricity
• Difficult to program
• Only experts could use them

Third Generation Computers (1960s-1970s):

Technology Used:

• Integrated Circuits (IC): Many tiny electronic parts on small chips
• Much smaller than vacuum tubes
• More reliable and faster

Characteristics:

• Size: Much smaller, size of large cabinets
• Weight: Much lighter than first generation
• Speed: Much faster processing
• Cost: Less expensive, more companies could buy
• Reliability: Broke down less often

Examples:

• IBM System/360: Popular business computer
• PDP-8: Smaller computer for special tasks
• Honeywell 6000: Used in many offices

Improvements:

• Could do many tasks at same time
• Easier to program
• More people could learn to use them
• Used less electricity

Comparison:

• First Generation: Vacuum tubes, very big, very expensive
• Third Generation: Integrated circuits, smaller, more affordable

Why Generations Matter:

• Shows how computers improved over time
• Each generation solved problems of previous generation
• Led to computers we use today