The Abstract View of Components of a Computer refers to a conceptual framework that outlines the main parts of a computer system, including the CPU, memory, input/output devices, and storage, without delving into the specific details of each component.
Hardware provides basic computing resources, including CPU, memory, and I/O devices.
An Operating System (OS) is a resource allocator that manages all resources and decides between conflicting requests for efficient and fair resource use.
Varying properties include access speed, capacity, data-transfer rate, and access method (sequential or random).
A System Call is a programmed request to the operating system to perform a specific task, such as accessing hardware or managing processes.
A process is a program in execution and a unit of work within the system, distinguishing it as an active entity compared to a passive program.
If a Soft Real Time System misses deadlines consistently, the performance of the system will deteriorate, making it unusable for users.
Operating systems that enable multiple tasks to be executed at the same time by managing the CPU's time effectively.
Utilities are programs that perform specific tasks, such as file manipulation, text processing, and system monitoring, enhancing the functionality of the Unix system.
Unix Architecture refers to the design and structure of the Unix operating system, which includes its kernel, shell, and utilities, allowing for multitasking and multi-user capabilities.
'Create process' is a system call used to initiate a new process in the operating system.
'Wait event' is a system call that causes a process to wait until a specific event occurs.
An operating system (OS) is the interface between user and computer hardware, managing the hardware attached to the computer system and performing various tasks such as memory management, controlling peripheral devices, handling input and output, and file management.
File Management is the function of the operating system that manages files and directories, allowing users to create, delete, save, and edit files stored in the computer's memory.
A multi user operating system is designed to allow multiple users to work simultaneously on a single computer system.
A system is a group of peripherals connected to each other to process input data and provide output.
System Calls are typically written in high-level languages such as C or C++.
Examples of multiprocessor operating systems include Linux, Unix, and Windows 2000.
Device Management system calls include operations such as requesting a device, releasing a device, reading, writing, repositioning, getting and setting device attributes, and logically attaching or detaching devices.
Modularity in the Layered Approach ensures that each layer uses functions and services only from lower-level layers, promoting organization and separation of concerns within the operating system.
Data is the information processed by the computer, which can be in various forms such as text, images, or audio.
Communications system calls include creating or deleting communication connections, sending and receiving messages, transferring status information, and attaching or detaching remote devices.
The API (Application Programming Interface) offers the services of the operating system to user programs, typically allowing access to system calls in a more user-friendly manner.
Wide Area Network.
The Process Control Subsystem is responsible for managing processes, including their creation, scheduling, and termination.
The Layered Approach in OS Structure is a design methodology that organizes the operating system into a series of layers, each built on top of the lower layers, allowing for modularity and easier management.
An Operating System controls the execution of programs to prevent errors and improper use of the computer.
The first multitasking operating system was created in the 1960s.
An API (Application Programming Interface) is a set of routines, protocols, and tools for building software and applications, allowing different software components to communicate with each other.
The Traditional Unix System Structure is a layered architecture that includes the kernel, shell, and various utilities, allowing for efficient process management and user interaction.
A Soft Real Time System is one where meeting deadlines is not compulsory for every task, but processes should still be executed to provide results. However, missing deadlines frequently can degrade system performance.
Operating systems that allow multiple users to access and use the system resources simultaneously.
A process needs resources such as CPU, memory, I/O, and files to accomplish its task.
The bottom layer (layer 0) in the Layered Approach is the hardware.
Users are individuals or entities that interact with the computer system to perform tasks or access information.
A multi-threaded process has one program counter per thread, allowing multiple threads to execute instructions concurrently.
'Terminate process' is a system call that ends the execution of a specified process.
'Open file' is a system call that allows a process to access a file for reading or writing.
Device Drivers are specialized software that allow the operating system to communicate with hardware devices.
The Buffer Cache is used to temporarily store data that is being transferred between the disk and memory, improving performance.
In a defense missile system, meeting deadlines is critical because a delay can change the destination of the missile, potentially leading to catastrophic consequences.
A program that acts as an intermediary between a user of a computer and the computer hardware.
Users are people, machines, or other computers that interact with the computer system.
Processing time requirements for a real-time operating system are measured in tenths of seconds or shorter increments of time.
The kernel is the core component of the Unix operating system that manages system resources, including memory, processes, and hardware interactions.
File-system management involves organizing files into directories and implementing access control to determine who can access what.
Real-time operating systems can be either event-driven, which switch between tasks based on priorities, or time-sharing, which switch tasks based on clock interrupts.
A collection of separate, possibly heterogeneous, systems networked together.
TCP/IP.
Concurrency is achieved by multiplexing the CPUs among the processes or threads, allowing multiple processes to run simultaneously.
Personal Area Network.
Memory Management is the process of coordinating and handling computer memory, including allocation, deallocation, and swapping.
Device Management is a function of the operating system used to manage different devices connected to the computer system, interacting with hardware through specified device drivers.
A multitasking operating system allows a user to perform multiple tasks simultaneously on a single computer system, also known as multiprocessing or multiprogramming operating systems.
The OS provides a uniform, logical view of information storage and abstracts physical properties to logical storage units, such as files.
A real-time operating system (RTOS) is an operating system intended to serve real-time applications that process data as it comes in, typically without buffer delays.
Real time systems are systems that are time-dependent, processing input data and providing output within a specified time frame.
The OS activities include creating and deleting files and directories, providing primitives to manipulate files and directories, and mapping files onto secondary storage.
Software consists of the programs and applications that instruct the hardware on how to perform tasks.
The three most common APIs are Win32 API for Windows, POSIX API for POSIX-based systems, and Java API for the Java virtual machine (JVM).
The purpose of backing up files is to store them onto stable (non-volatile) storage media to prevent data loss.
Examples of Real Time Operating Systems include MTOS, Lynx, and RTX.
Process Control system calls manage the execution of processes, including operations such as creating, terminating, and modifying process attributes.
The System Call Interface is a set of functions that allows user programs to request services from the operating system's kernel.
Inter-process Communication (IPC) refers to mechanisms that allow processes to communicate and synchronize their actions.
The kernel is a central component of an operating system that acts as an interface between user applications and the hardware, managing communication between software and hardware.
Application programs define the ways in which the system resources are used to solve the computing problems of the users, such as word processors, compilers, and web browsers.
If a missile does not meet its deadline, it may arrive at the wrong destination, which can have serious implications for national security.
To execute user programs and make solving user problems easier, make the computer system convenient to use, and use the computer hardware in an efficient manner.
Examples of multitasking operating systems include Linux, Unix, Windows 2000, Windows XP, and Windows 10.
APIs serve as the interface through which applications make System Calls to the operating system, enabling the applications to request services and resources from the OS.
The shell acts as an interface between the user and the kernel, allowing users to execute commands and run programs.
The device-driver interface serves as a general interface between the operating system and hardware devices, facilitating communication and control.
Operating systems designed to process data as it comes in, typically used in environments where timing is critical.
The Unix Kernel is the core component of the Unix operating system that manages system resources, including memory, processes, and hardware interactions.
Unix Utilities are a collection of tools and programs that perform specific tasks, such as file manipulation, text processing, and system monitoring, enhancing the functionality of the Unix operating system.
The Scheduler determines the order in which processes are executed by the CPU, optimizing resource use and system performance.
User Level refers to the execution context of user applications, while Kernel Level refers to the execution context of the operating system's core functions.
Windows System Calls are the interfaces provided by the Windows operating system that allow applications to request services from the kernel, such as file operations, process management, and memory allocation.
Unix System Calls are the fundamental interfaces in Unix-like operating systems that enable user applications to interact with the kernel, performing tasks like file manipulation, process control, and inter-process communication.
System Calls are the programming interface to the services provided by the operating system, allowing programs to request services from the OS.
A computer system with multiple CPUs processes faster than a system that contains a single CPU.
A Real Time Operating System (RTOS) is an operating system specially designed to handle real time applications that must execute within a specific period of time, where time is a major constraint.
The Layered Approach in OS Structure divides the operating system into multiple layers, each built on top of lower layers, with the bottom layer being hardware and the highest layer being the user interface.
A real-time system is a time-bound system that has well-defined fixed time constraints, where processing must be done within these constraints to avoid system failure.
Information Maintenance system calls involve getting or setting the time or date, retrieving or updating system data, and getting or setting attributes for processes, files, or devices.
APIs are used rather than direct system calls because they provide a higher-level, more user-friendly interface for accessing OS services, simplifying programming tasks.
Examples of Soft Real Time Systems include personal computers, audio systems, and video systems.
Local Area Network.
Metropolitan Area Network.
It allows systems to exchange messages.
A Trap is an exception or interrupt that occurs during program execution, signaling the operating system to take control.
Memory Management is the process that determines what is in memory and when, ensuring that all (or part) of the instructions and data needed by a program are available in memory for execution.
Memory Management activities include keeping track of which parts of memory are currently being used and by whom, deciding which processes and data to move into and out of memory, and allocating and de-allocating memory space as needed.
The number of tasks processed simultaneously depends on the speed of the CPU, the capacity of memory, and the size of programs.
Operating systems that execute a series of jobs in batches without user interaction.
An Application Program Interface (API) is a set of routines, protocols, and tools for building software and applications, allowing programs to access system calls indirectly.
Processor Management is responsible for managing all the running processes in a computer system, where a process is defined as a program executed by a user.
The two types of Real Time Operating Systems are Hard Real Time Operating Systems and Soft Real Time Operating Systems.
Process termination requires the reclamation of any reusable resources.
A single-threaded process has one program counter that specifies the location of the next instruction to execute.
Operating systems specifically designed to operate on embedded systems, often with limited resources and specific functions.
The File Subsystem manages the reading, writing, and organization of files on storage devices, providing an interface for file operations.
The illusion of a single system.
A Hard Real Time System is a purely deterministic and time-constrained system that must produce output within a specified deadline, such as processing input data and providing output exactly by the 10th second.
An operating system performs various tasks regarding the computer system, including memory management, controlling peripheral devices such as disk drives and printers, handling input and output, and file management.
A hard real-time system is one where meeting deadlines is crucial; failure to meet a deadline can result in system performance failure.
A multiprocessor operating system allows the computer system to use more than one CPU in a single system for executing multiple processes simultaneously.
The four components of a computer system are hardware, software, data, and users.
Buffering is the temporary storage of data while it is being transferred, allowing for smoother data flow between devices.
In a batch processing operating system, jobs are combined in the form of batches and given to the system as input data.
Hard Real Time Systems are a category of real time systems that must meet strict timing constraints.
Spooling is the overlapping of output from one job with the input of other jobs, allowing for more efficient processing.
Security Management ensures the protection of a computer system from various threats and virus attacks, utilizing techniques such as authentication, authorization, and cryptography.
A system call is a mechanism that provides the interface between a process and the operating system, allowing a computer program to request a service from the kernel of the OS.
A Real Time Operating System is similar to a multitasking operating system in that it can manage multiple tasks, but it is specifically designed to handle real time applications.
A Unix Shell is a command-line interface that allows users to interact with the operating system by executing commands and running scripts.
'Create file' is a system call that generates a new file in the file system.
The main tasks of the kernel include process management, device management, memory management, interrupt handling, I/O communication, and file system management.
A batch processing operating system is capable of executing one job at a time, where jobs are combined into batches and processed on a first-come, first-served basis without human interaction.
Examples of multi user operating systems include Unix, Linux, Windows 2000, and VM – 386.
Memory Management optimizes CPU utilization by ensuring that the necessary instructions and data are in memory, which improves the computer's response time to users.
Memory Management is the process that manages the allocation of memory in a system for different processes, overseeing both primary and secondary memory.
Real time applications are those applications that must execute within a specific period of time, making time a critical constraint for their operation.
A system call is a programmatic way in which a computer program requests a service from the operating system's kernel.
Yes, a Soft Real Time System can miss deadlines, but it should do so according to the priority of the tasks involved.
Real Time Operating Systems are designed to manage hardware resources and process data within strict timing constraints.
Operating systems that support the use of multiple processors to perform tasks simultaneously, improving performance.
System calls are typically written in high-level languages such as C or C++.
It provides features between systems across a network.
'Set file attributes' is a system call that modifies the properties of a specified file.
The Operating System controls and coordinates the use of hardware among various applications and users.
The I/O Subsystem is a component of the operating system responsible for managing input/output operations, including memory management of I/O, device-driver interfaces, and drivers for specific hardware devices.
Jobs in a batch processing operating system are processed on a first-come, first-served basis, with the operating system fetching another job from input data after the completion of the current job.
Hardware refers to the physical components of a computer system, including the CPU, memory, storage devices, and input/output devices.
Caching refers to storing parts of data in faster storage to improve performance during data access.
No, there is no need for human interaction before fetching the next job after the completion of any job in a batch processing operating system.
Soft Real Time Systems are a category of real time systems where timing constraints are less strict and can be relaxed.
The sequence typically includes opening the source file, reading its contents, opening the destination file, writing the contents to the destination file, and then closing both files.
The highest layer (layer N) in the Layered Approach is the user interface.
The three most common APIs are Win32 API for Windows, POSIX API for POSIX-based systems (including UNIX, Linux, and Mac OS X), and Java API for the Java virtual machine (JVM).
Programs mostly access system calls via a high-level Application Program Interface (API) rather than using direct system call methods.
'Read' is a system call that retrieves data from a file into a process's memory.
Examples of security threats include denial-of-service attacks, worms, viruses, identity theft, and theft of service.
Examples of embedded operating systems include the Palm operating system and Windows CE.
An embedded operating system is similar to a real-time operating system in that both are designed to perform specific tasks within strict timing constraints.
The deadline in a Hard Real Time System is the specific time by which the system must complete processing and provide output; for example, if the deadline is 10 seconds, the output must be given exactly at that time, not earlier or later.
A User ID is an identifier that includes a name and an associated number, one per user, used to determine access control.
An embedded operating system is installed on an embedded computer system primarily used to perform computational tasks in electronic devices.
Privilege escalation allows a user to change to an effective ID with more rights.
Protection is any mechanism for controlling access of processes or users to resources defined by the OS.
Security refers to the defense of the system against internal and external attacks.
A Group ID allows a set of users to be defined and controls managed, and is associated with each process and file.
