Page 17 - Viva ICSE Computer Studies 8 : E-book

Real-Time Operating System

A real-time operating system is a system in which the time interval required to process and
respond to input is so small that it controls the environment. It is used when there are rigid
time requirements on the operation of a processor or the fl ow of data. Such operating systems
must have well-defi ned and fi xed time constraints to prevent system failure. Medical imaging
systems, industrial control systems, weapon systems and air traffi c control systems are some
examples of real-time operating systems.

Distributed Operating System
Learn More
Distributed operating system uses multiple central
MS-DOS, developed by ‘Microsoft Inc.’
processors to serve multiple real-time applications
in 1981, has been the most widely used
and multiple users. The systems are located in diff erent
operating system of IBM-compatible
geographical areas and the processors communicate microcomputers.
with one another through various communication
lines (such as high-speed buses or telephone lines). These are referred to as loosely coupled
systems or distributed systems. Processor in a distributed system may vary in size and function.

User Interface

A point where two systems meet and interact with each other is called interface. For example,
an operating system acts as an interface between a user and hardware. A user cannot interact
with a computer without an operating system.

Types of User Interface
Think and Discuss
There are two types of user interface. Let’s discuss them in
detail. List some examples of character
user interface.
Character User Interface (CUI)
Character user interface is a command-based interface where the user needs to type commands
to interact with the computer system. The beginners are not comfortable with such interface
as they need to memorise the commands.

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