Operating System
Short Questions Answers
1. Explain the terms hardware interrupts and software interrupts.
An interrupt is a signal generated by hardware or software components when they require time of CPU. Interrupts are usually given high priority by OS. When an interrupts occurs, processing task of CPU is stopped, interrupting task is executed after which previous task will resume.
There are two types of interrupts:
- Hardware interrupt
- Software interrupt
Hardware interrupt
It is the interrupting signal generated from hardware components like I/O devices, network devices and memory device. It can be created due to malfunctioning of hardware, plug and play devices, I/O operation. It interrupts the CPU directly.
Software interrupt
It is the interrupting signal generated from software components like application programs, OS itself, process scheduling. It is also generated due to error in the software, memory overflow, context switching. It interrupts the kernel of the OS and kernel instructs the CPU to execute the interrupting signal.
2. Describe the terms spooling and buffering.
Spooling is the process of using SPOOL (Simultaneous Peripheral Operation On-Line). It is the concept of using the peripheral devices like input/output device at the same time when the CPU is busy executing other task. With the use of this concept, CPU doesn’t require to wait for the operation of peripheral devices to be completed for executing other task. This concept is commonly used in printing process. While printing multiple documents, CPU processes it and instructs the printer to print. Since, printing process is slow, if spooling is not used CPU has to wait to execute other task until the printing is over. But, due to concept of spooling, printing is handled by spool and CPU remains free for other jobs.
Buffering is concept of using buffer during input/output operations. A buffer is a temporary, high speed memory located in I/O devices. It stores data at the time of input/output operations. Buffering is used to balance the difference in operating speed of different devices and manage data transfer speed between them. The buffering is also used while accessing files like audio/video through Internet. In this case, it is the process of downloading sufficient data before it is played.
3. What is software?
Software is a collection of program. Program is a collection of instruction. An instruction is a command given to the computer to perform some specific task. So, software can be defined as the collection of instruction that instructs the computer to perform a particular task. It acts as the interface between user and the hardware and makes the hardware operate able.
4. Describe the types of computer booting.
Booting is the process of initializing the computer. It is the process of loading system files in the system memory. It is the process of loading the operating system files in the primary memory. This results in starting of the computer and making it ready to use it.
Types of Computer Booting Types of computer booting are:
- Cold booting
- Warm booting
Cold booting
It is the process of loading the system files in the system memory when the computer is previously in OFF state. It results in starting of the computer from OFF state. It is also called as hard boot.
Warm booting
It is the process of reloading the system file in the system memory when the computer is previously in ON state. It results in restarting or resetting of the computer from ON state. It is also called as soft boot.
5. List out the name of operating system. What are the main feature of GUI based operating system?
Some of the operating system are:
- Windows
- Mac OS
- Linux
- Android
- MS DOS
- iOS
- UNIX
- Ubuntu
Main features of GUI based operating system are:
- It contains graphics, colour, icon and picture.
- It is attractive and user friendly.
- It is easier to use.
- User doesn’t require remembering and understanding the commands.
- It supports pointing device like mouse, joystick and light pen.
- It has larger memory and processing requirement.
- It is usually 32 or 64 bit OS.
- It supports multitasking, multiprogramming, multiprocessing, multi user.
- It supports multimedia.
- It is slower than CUI based OS.
6. What is Real Time Operating System? Explain. [5]
Real time system is an online system in which processing times is critical. Every task has to be completed in a predefined time. Changes in the processing time can result in loss or accident. Real times operating system (RTOS) is used to operating controlling and managing real times systems.
RTOS has features like:
- It has very fast processing capabilities with very low delays.
- It performs actions within the known time frame and produce known output.
- It responds to input immediately.
- It can be either hard or soft real time.
- It can be either time sharing or event driven.
- It is highly reliable.
RTOS is used in robotics, complex multimedia animation system, communication, military, government system, industrial, aviation applications.
7. Define multi processing and multi tasking operating system.
- Multiprocessing OS
It supports execution of multiple processes at a same time. To execute multiple processes, multiple processors (CPU) are required. It is also called as parallel processing, in which multiple processors work in parallel to execute multiple task simultaneously. It is more costly and complex. It increases the program execution speed of the computer. Example: UNIX, MVS.
- Multitasking OS
This type of OS is capable of supporting multiple tasks at a time. For executing multiple task, it use time sharing concept. It increases the productivity of the users for use of computers, as user can perform multiple tasks simultaneously. Example: Windows, Linux, Mac OS.
8. Differentiate between single-user and multi-user operating system.
| Multi-User Operating System | |
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Long Questions Answers
1. What is an operating system? Why is GUI operating system more popular than text based operating system? Justify clearly.
Operating system (OS) is system software that manages hardware and software resources of the computer and makes it ready to use. It is a collection of programs that controls the overall operation of the computer. It acts as the interface between user and hardware. Example: MS Windows, MS DOS, Linux, Android.
GUI (Graphical User Interface) contains graphics, color, icon and picture. It is attractive and user friendly. It is easier to use. Example: Windows, Mac OS, Android. CUI (Character/Command User Interface) contains only the text with no graphics. It is difficult and not attractive for the beginners. Example: MS DOS, UNIX, Linux.
Reasons for Popularity of GUI than Text Based Operating System
GUI operating system is more popular than text based operating system because of:
- It contains graphics, color, icon and picture.
- It is attractive and user friendly.
- It is easier to use.
- User doesn’t require remembering and understanding the commands.
- It supports pointing devices like mouse, joystick and light pen.
- It supports multitasking, multiprogramming, multiprocessing, and multi-user.
2. What is an operating system? Describe GUI and CUI operating systems in detail.
Operating system (OS) is system software that manages hardware and software resources of the computer and makes it ready to use. It is a collection of programs that controls the overall operation of the computer. It acts as the interface between user and hardware. Example: Windows, MS DOS, Linux, Android.
GUI (Graphical User Interface) contains graphics, color, icon and picture. It is attractive and user friendly. It is easier to use. User doesn’t require remembering and understanding the commands. It supports pointing devices like mouse, joystick and light pen. It has a larger memory and processing requirement. It is usually a 32 or 64 bit OS. It supports multitasking, multiprogramming, multiprocessing, and multi-user. It supports multimedia. Example: Windows, Mac OS, Android.
CUI (Character/Command User Interface) contains only the text with no graphics. It is difficult and not attractive for the beginners. User needs to understand and remember the command. It doesn’t support pointing devices like mice. It has low memory and processing requirements. It is usually an 8 or 16 bit OS. It doesn’t support multimedia. Example: MS DOS, UNIX, Linux.
3. What is an operating system? Explain the functions of an operating system.
Operating system (OS) is system software that manages hardware and software resources of the computer and makes it ready to use. It is a collection of programs that controls the overall operation of the computer. It acts as the interface between user and hardware. Example: Windows, MS DOS, Linux, Android.
Functions of Operating System The functions of operating system are:
- Process Management: It refers to the management of CPU and its processing task. It includes creating processes, allocating resources for the process, scheduling, executing and terminating the process after the execution is over.
- Memory Management: It is the process of managing both primary and secondary memory of the computer. It includes allocating memory space for the process while creating the process and freeing it after the processing is over.
- Input/Output Management: It is the process of managing input/output devices and their operations. All the input/output operations are controlled and managed by the operating system. It allows computers to interact with peripheral devices.
- Virtual Memory Management: In a multiprogramming environment, when we multiple programs at the same time, the space of primary memory may not be enough for storing all the programs. In this case, the OS uses free space of secondary memory to store those contents. This space in secondary memory, used for storing the contents of primary memory, is called virtual memory. OS is responsible for creating, managing and using virtual memory. Modern OS like windows can increase or decrease the size of virtual memory automatically as per need.
- File Management: A file is a collection of data. File management function of the OS is related to all the file operations including: creating the file, storing data in the file, update, delete operations in the file, managing file attributes, keeping track of all file information.
4. What do you mean by the term ‘Virtual memory’? How does it differ from ‘main memory’ and ‘secondary memory’? Discuss,
In a multiprogramming environment, when we use multiple programs at the same time, the space of primary memory may not be enough for storing all the programs. In this case, the OS uses free space of secondary memory to store those contents. This space in secondary memory, used for storing the contents of primary memory, is called virtual memory. OS is responsible for creating, managing and using virtual memory. Modern OS like windows can increase or decrease the size of virtual memory automatically as per need.
Differentiation between Virtual Memory and Main Secondary Memory
| Virtual memory | Main memory and secondary memory |
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5. Define an operating system. What is its purpose? List the functions. [12.5]
Operating system (OS) is system software that manages hardware and software resources of the computer and makes it ready to use. It is a collection of programs that controls the overall operation of the computer. It acts as the interface between user and hardware. Example: MS Windows, MS DOS, Linux, Android.
The purposes of operating system are:
- It makes the computer operate able and ready to use by creating the environment to use application software.
- It acts as an interface between the user and the hardware.
- It hides the complexities of the hardware from the user.
- It manages process and processing components, both primary and secondary memory, Input/output devices and input/output operations.
- It provides a security mechanism for the protection of computing resources from unauthorized access.
- It handles interrupts.
- It prevents deadlock, detect and recover from the deadlock after it is detected.
- It creates and manages virtual memory.
- It interprets the command provided by the user and instructs it to execute those commands.
- It creates and manages files on the computer.
The functions of operating system are:
- Process management
- Memory management
- Input/Output management
- Virtual memory management
- File management
- Providing security
- Providing user interface
- Interrupt handling
- Deadlock prevention
- Command interpreter