Batch OS ,Time Sharing OS , Real Time Operating System

Lists of Questions answers And Study notes

  • (1) Give the features of Batch Operating System.
  • (2) Explain the features of Time Sharing System. .
  • (3) Explain the features of Real Time Operating System.

 

Question-1 Give the features of Batch Operating System.

 

  • Batch operating system is one that processes routine jobs without any interactive user presents. Such as claim processing in insurance and sales reporting etc.
  • To improve utilization, the concept of batch operating system was developed.
  • Jobs with similar needs were batched together and were run through the computer as a group.
  • Thus, the programmer would leave their program with operator, who in turn would sort program into batches with similar requirements.
  • The operator then loaded a special program (the ancestor of today’s operating system), which read the first job from magnetic tape and run it.
  • The output was written onto a second magnetic tape, instead of being printed.
  • After each job finished, the operating system automatically read the next job from the tape and began running it.
  • When the whole batch was done, the operator removed the input and output tapes, replaced the input tape with the next batch, and brought the output tape for offline printing.
  • With the use of this type of operating system, the user no longer has direct access to machine.

 

Advantages:

  • Move much of the work of the operator to the computer.
  • Increase performance since it was possible for job to start as soon as the previous job finished.

 

Disadvantages:

  • Large Turnaround time.
  • More difficult to debug program.
  • Due to lack of protection scheme one batch job can affect pending jobs.

 

Question-2 Explain the features of Time Sharing System.
  • Time Sharing is a logical extension of multiprogramming.
  • Multiple jobs are executed simultaneously by switching the CPU back and forth among them.
  • The switching occurs so frequently (speedy) that the users cannot identify the presence of other users or programs.
  • Users can interact with his program while it is running in timesharing mode.
  • Processor’s time is shared among multiple users. An interactive or hands on computer system provides online communication between the user and the system.
  • A time shared operating system uses CPU scheduling and multiprogramming to provide each user with a small portion of a time shared computer. Each user has at least one separate program in memory.
  • A time shared operating system allows many users to share computer simultaneously. Since each action or command in a time shared system tends to be short, only a little CPU time is needed for each user.

 

Advantages :-

  • Easy to use
  • User friendly
  • Quick response time

 

Disadvantages:-

  • If any problem affects the OS, you may lose all the contents which have stored already.
  • Unwanted user can use your own system in case if proper security options are not available.

 

Question-3 Explain the features of Real Time Operating System.

A real time operating system is used, when there are rigid (strict) time requirements on the operation of a processor or the flow of data.

  • It is often used as a control device in a dedicated application. Systems that control scientific experiments, medical imaging systems, and industrial control system are real time systems. These applications also include some home appliance system, weapon systems, and automobile engine fuel injection systems.
  • Real time Operating System has well defined, fixed time constraints. Processing must be done within defined constraints or the system will fail.
  • Since meeting strict deadlines is crucial in real time systems, sometimes an operating is simply a library linked in with the application programs.
  • There are two types of real time operating system,

 

Hard real system:

  • This system guarantees that critical tasks complete on time.
  • Many of these are found in industrial process control, avionics, and military and similar application areas.
  • This goal says that all delays in the system must be restricted.

 

Soft real system:

  • In soft real-time system, missing an occasional deadline, while not desirable, is acceptable and does not cause any permanent damage.
  • Digital audio or multimedia systems fall in this category.

An example of real time system is e-Cos.