Introduction to

D
Fourth generation (late 1970s,early 1989s,) 
• Greatly expanded storage capabilities and improved circuitry.
• Has a large-scale integrated circuits (LSI) which has several hundred 
thousands transistors placed on one tiny silicon chip.

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Unit 1: Introduction to Computer Systems
31
• Computer memory operates at speeds of nano seconds (billionths of a 
second) with large computers capable of adding 15 million numbers per 
second.
E
Fifth generation
The fifth generation computer development is still in progress. An architecture, which makes 
use of the changes in technology and allows a simple and natural methodology for solving 
problems, is being sought. These computers will have intelligent processors i.e., processors 
which can draw inferences. Users will also be able to interact with them in natural languages 
such as in plain English or a particular language of choice.
Activity Conclusion
The task of entering and altering programs for the ENIAC was extremely tedious. The 
limitations of early days computers were successfully addressed through the Von Neumann 
architecture which you will learn in the next unit. Computers evolution is grouped into four 
generations with each generation characterised by the dominant electronic component used, 
the type of programming language as well as the type of operating systems used.
Assessment: Reflective Activities
a. What was the type of electronic component used in the second generation of 
computers?
b. What type of operating system was used in the first generation of computers?
c. The type of operating system used in the third generation was a time sharing 
one, what does time sharing mean?
Answers
a. Vacuum tube
b. There was no notion of operating system then, it was programmer who also 
assumes the role of operating system by connecting or disconnecting wires
c. Time sharing operating systems are systems that enables program share the 
computer resources including the CPU based on a scheduled time.

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