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3. Multi-user operating system

A multi-user operating system allows multiple users, on different workstations, to access a single, powerful computer via a network.   This central computer, often a mainframe or super-computer,  contains the operating system which is used on all connected terminals.

The diagram below shows a typical multi-user system that includes a mainframe computer. Note that there is a single computer (the mainframe) with multiple terminals/workstations. The workstations are not running their own operating systems, but are controlled by a single larger one on the mainframe.

multi-user operating system


As you can see in the above diagram, a multi-user operating system handles the needs of different users by dividing up CPU time and assigning blocks to each user in turn. Since a computer works so quickly, these blocks are shorter than a human would notice (about a hundredth of a second).

A multi-user operating system carries out the following tasks

  • Each user logs on to the system and is presented with their workspace
  • Allocates resources for the jobs they want to run
  • Keeps logs of how much processing time and resources they use
  • Works out the most efficient use of computer processing cycles
  • Maintains security and privacy between the different users

Examples of multiuser operating systems include automated checkouts at a supermarket, a mainframe in an office, etc.

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