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TYPES OF OPERATING SYSTEM
TYPES OF OPERATING SYSTEM
Operating systems are there from the very first computer generation. Operating systems keep
evolving over the period of time. Following are few of the important types of operating system
which are most commonly used.
Batch operating system
The users of batch opera ting system do not interact with the computer directly. Each user
prepares his job on an off-line device like punch ca rds and submits it to the com puter operator. To
speed up processing, jobs with similar needs are batched together and run as a group. Thus, the
programme rs left their programs with the operator. The operator then sorts programs into batches
with similar requirements.
The problems with Batch Systems are following.
Lack of interaction between the user and job.
CPU is often idle, because the speeds of the mechanical I/O devices is slower than CPU.
Difficult to provide the desired prio rity.
Time-sharing operating systems
Time sharing is a technique which enables many people, located at various terminals, to use a
particular computer system at the same time. Time-sharing or multitasking is a logical extension
of multiprogramming. Processor's time which is shared among multiple users simultaneously is
termed as time-sharing. The main difference between Multiprogrammed Batch Systems and Time-
Sharing Systems is that in case of Multiprogrammed batch systems, objective is to maximize
processor use, whereas in Time-Sharing Systems objective is to minimize response time.
Multiple jobs are executed by the CPU by switching between them, but the switches occur so
frequently. Thus, the user can receives an immediate response. For example, in a transaction
processing, processor execute each user program in a short burst or quantum of computation.
That is if n users are present, each user can get time quantum. When the user submits the
command, the response time is in few seconds at most.
Operating system uses CPU scheduling and multiprogramm ing to provide each user with a small
portion of a time. Computer systems that were designed primarily as batch systems have been
modified to time-sharing systems.
Advantages of Timesharing operating systems are following
Provide advantage of quick response.
Avoids duplication of software.
Reduces CPU idle time.
Disadvantages of Timesharing operating systems are following.
Problem of reliability.
Question of security and integrity of user programs and data.
Problem of data communication.
Distributed operating System
Distributed systems use multiple central processors to serve multiple real time application and
multiple users. Data processing jobs are distributed among the processors acco rdingly to which
one can perform each job most efficiently.
