Hello guys... okay today i'm gonna share about OP. What is that?
okay keep reading yaa.
Definition of Operating System:
1. An operating system (OS) is a software, that manages the computer hardware, and provides common services for execution of various application software [4]. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between application programs and the computer hardware [3].
2. An operating system (sometimes abbreviated as "OS") is the program that, after being initially loaded into the computer by a boot program, manages all the other programs in a computer [1].
Objectives of Operating System:
1. Convenience: makes computer user friendly.
2. Efficiency: allows computer to use resources efficiently.
3. Ability to evolve: constructed in a way to permit effective development, testing and introduction of new functions without interfering with service [6].
Functions of Operating System:
1. Resource Management: The resource management function of an OS allocates computer resources such as CPU time, main memory, secondary storage, and input and output devices for use [5].
a. Process Management: The operating system is responsible for the following activities in connection with process management:
i. Creating and deleting both user and system processes.
ii. Suspending and resuming processes.
iii. Providing mechanisms for process synchronization.
iv. Providing mechanisms for process communication [4].
v. Providing mechanisms for deadlock handling.
b. Memory Management: The operating system is responsible for the following activities in connection with memory management:
i. Keeping track of which parts of memory are currently being used and by whom.
ii. Deciding which processes and data to move into and out of memory.
iii. Allocating and deallocating memory space as needed [4].
c. Storage Management:
i. File – System Management: The operating system is responsible for the following activities in connection with the file management:
· Creating and deleting files
· Creating and deleting directories to organize files.
· Supporting primitives for manipulating files and directories.
· Mapping files onto secondary storage.
· Backing up files on stable (nonvolatile) storage media [4].
ii. Mass – Storage Management: The operating system is responsible for the following activities in connection with disk management:
· Free-space Management
· Storage Allocation
· Disk Scheduling [4].
d. Device Management: One of the purposes of operating system is to hide the peculiarities of specific hardware devices from the user.
2. Data Management: The data management functions of an OS govern the input and output of the data and their location, storage, and retrieval [5].
3. Job Management: The job management function of an OS prepares, schedules, controls, and monitors jobs submitted for execution to ensure the most efficient processing. A job is a collection of one or more related programs and their data [5].
4. Standard means of communication between user and computer: The OS establishes a standard means of communication between users and their computer systems. It does this by providing a user interface and a standard set of commands that control the hardware [5].
5. In a multitasking operating system where multiple programs can be running at the same time, the operating system determines which applications should run in what order and how much time should be allowed for each application before giving another application a turn [1].
6. It manages the sharing of internal memory among multiple applications [1].
7. It handles input and output to and from attached hardware devices, such as hard disks, printers, and dial-up ports [1].
8. It sends messages to each application or interactive user (or to a system operator) about the status of operation and any errors that may have occurred [1].
9. It can offload the management of what are called batch jobs (for example, printing) so that the initiating application is freed from this work [1].
10. On computers that can provide parallel processing, an operating system can manage how to divide the program so that it runs on more than one processor at a time [1].
11. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers [2].
12. The operating system is also responsible for security, ensuring that unauthorized users do not access the system [2].
Types of Operating System:
1. Batch Operating System: Batch operating system is the operating system which analyzes your input and groups them into batches i.e. data in each batch is of similar characteristics. And then it performs operation on each individual batch.
2. Real-time: A real-time operating system is a multitasking operating system that aims at executing real-time applications. Real-time operating systems often use specialized scheduling algorithms so that they can achieve a deterministic nature of behavior. The main object of real-time operating systems is their quick and predictable response to events. They either have an event-driven or a time-sharing design. An event-driven system switches between tasks based on their priorities while time-sharing operating systems switch tasks based on clock interrupts [3].
a. Hard real-time system: It has the most stringent requirements, guaranteeing that real-time tasks be completed within their deadlines. Safety-critical systems are typically hard real-time systems [4].
b. Soft real-time system: It is less restrictive, simply providing that a critical real-time task will receive priority over other tasks and that it will retain that priority until it completes. Many commercial operating systems – as well as Linux – provide soft real-time support [4].
3. Multi-user vs. Single-user: A multi-user operating system allows multiple users to access a computer system concurrently. Time-sharing system can be classified as multi-user systems as they enable a multiple user access to a computer through the sharing of time. Single-user operating systems, as opposed to a multi-user operating system, are usable by a single user at a time. Being able to have multiple accounts on a Windows operating system does not make it a multi-user system. Rather, only the network administrator is the real user. But for a Unix-like operating system, it is possible for two users to login at a time and this capability of the OS makes it a multi-user operating system [3].
4. Multi-tasking vs. Single-tasking: When a single program is allowed to run at a time, the system is grouped under a single-tasking system, while in case the operating system allows the execution of multiple tasks at one time, it is classified as a multi-tasking operating system. Multi-tasking can be of two types namely, pre-emptive or co-operative. In pre-emptive multitasking, the operating system slices the CPU time and dedicates one slot to each of the programs. Unix-like operating systems such as Solaris and Linux support pre-emptive multitasking. Cooperative multitasking is achieved by relying on each process to give time to the other processes in a defined manner. MS Windows prior to Windows 95 used to support cooperative multitasking [3].
5. Single-processor Systems: On a single-processor system, there is one main CPU capable of executing a general-purpose instruction set, including instructions from user processes [4].
6. Multi-processor Systems: A multiprocessing operating system allows a program to run on more than one central processing unit (CPU) at a time. This can come in very handy in some work environments, at schools, and even for some home-computing situations.
a. Asymmetric multiprocessing: In this each processor is assigned a specific task. A master processor controls the system; the other processors either look to the master for instruction or have predefined tasks. This scheme defines a master-slave relationship. The master processor schedules and allocates work to the slave processors [4].
b. Symmetric multiprocessing (SMP): In this each processor performs all tasks within the operating system. SMP means that all processors are peers; no master-slave relationship exists between processors [4].
7. Distributed: A distributed operating system manages a group of independent computers and makes them appear to be a single computer. The development of networked computers that could be linked and communicate with each other, gave rise to distributed computing. Distributed computations are carried out on more than one machine. When computers in a group work in cooperation, they make a distributed system [3].
8. Embedded: Embedded operating systems are designed to be used in embedded computer systems. They are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources. They are very compact and extremely efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems [3].
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Windows
Windows is a series of operating systems developed by Microsoft. Each version of Windows includes a graphical user interface, with a desktopthat allows users to view files and folders in windows. For the past two decades, Windows has been the most widely used operating system for personal computers PCs.
Microsoft Windows is designed for both home computing and professional purposes. Past versions of Windows home editions include Windows 3.0 (1990), Windows 3.1 (1992), Windows 95 (1995), Windows 98 (1998), Windows Me (2000), Windows XP (2001), and Windows Vista (2006). The current version, Windows 7, was released in 2009.
The first business-oriented version of Windows, called Windows NT 3.1, was in 1993. This was followed by Windows 3.5, 4.0, and Windows 2000. When Microsoft released Windows XP in 2001, the company simply created different editions of the operating system for personal and business purposes. Windows Vista and Windows 7 have followed the same release strategy.
Windows is designed to run on standard x86 hardware, such as Intel and AMD processors. Therefore, it can be installed on multiple brands of hardware, such as Dell, HP, and Sony computers, as well as home-built PCs. Windows 7 also includes several touchscreen features, that allow the operating system to run on certain tablets and computers with touchscreen displays. Microsoft's mobile operating system, Windows Phone, is designed specifically for smartphones and runs on several brands of phones, including HTC, Nokia, and Samsung.
t5e BIOS
(ba(basic input/output system) is the program a personal computer's microprocessor uses to get the computer system started after you turn it on. It also manages data flow between the computer's operating system and attached devices such as the hard disk, video adapter, keyboard, mouse and printer.
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BIOS is an integral part of your computer and comes with it when you bring it home. (In contrast, the operating system can either be pre-installed by the manufacturer or vendor or installed by the user.) BIOS is a program that is made accessible to the microprocessor on an erasable programmable read-only memory (EPROM) chip. When you turn on your computer, the microprocessor passes control to the BIOS program, which is always located at the same place on EPROM.
When BIOS boots up (starts up) your computer, it first determines whether all of the attachments are in place and operational and then it loads the operating system (or key parts of it) into your computer's random access memory (RAM) from your hard disk or diskette drive.
With BIOS, your operating system and its applications are freed from having to understand exact details (such as hardware addresses) about the attached input/output devices. When device details change, only the BIOS program needs to be changed. Sometimes this change can be made during your system setup. In any case, neither your operating system or any applications you use need to be changed.
Although BIOS is theoretically always the intermediary between the microprocessor and I/O device control information and data flow, in some cases, BIOS can arrange for data to flow directly to memory from devices (such as video cards) that require faster data flow to be effective.
SSTARTUP MENU
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The Microsoft Windows Start Menu is the primary location in Windows to locate your installed programs and find any files or folders. By default, the Start Menu is accessed by clicking the Start button, located in the bottom left-hand corner of the Windows Desktop screen. The picture to the right is an example of how the Windows 7 Start Menu may appear.
Note: In Windows 8 and Windows 8.1, the Start Menu has been replaced by the Start Screen. The Start Menu returned in Windows 10 and is discussed later on this page.
Tip: You can press the Windows key on the keyboard or the Ctrl+Esc keyboard shortcut to open the Start Menu.
What is accessible in the Start Menu?
Below is an overview of the Windows Start Menu found in Microsoft Windows XP and Windows 7. If you have Windows 10 Skip down to the Windows 10 Start Menu section.
Left Pane
The left pane shows recently-run programs or any pinned program shortcuts. In the above example, there is one pinned program separated by a line and then the recently ran programs.
All Programs
At the bottom of the left pane is the "All Programs" option, which displays all programs that have been installed on the computer.
Search
Directly below the All Programs option is the "Search" bar. This useful feature allows you to type in the name of the program or file you're looking for and have the results displayed above.
Right Pane
The right pane shows each of the more commonly accessed sections of the computer, such as your Computer, Control Panel, Documents, Music, and Pictures.
Tip: You can find the version of Windows on your computer if you right-click on Computerand select Properties. In the System window you can view basic system properties, including the Windows version and access the Device Manager.
Shut down
At the bottom of the right pane is the Shut down button, which allows you to turn the computer off. You can also click the arrow next to the Shut down button to switch user, Log off, Restart, Sleep, or Hibernate the computer.
Windows Installer
Windows Installer (previously known as Microsoft Installer,[3]codename Darwin[4][5]) is a software component and application programming interface (API) of Microsoft Windows used for the installation, maintenance, and removal of software. The installation information, and optionally the files themselves, are packaged in installation packages, loosely relational databases structured as COM Structured Storages and commonly known as "MSI files", from their default filename extensions. Windows Installer contains significant changes from its predecessor, Setup API. New features include a GUI framework and automatic generation of the uninstallation sequence. Windows Installer is positioned as an alternative to stand-alone executable installer frameworks such as older versions of InstallShield and NSIS.
Before the introduction of Windows Store, Microsoft encouraged third parties to use Windows Installer as the basis for installation frameworks, so that they synchronize correctly with other installers and keep the internal database of installed products consistent. Important features such as rollback and versioning depend on a consistent internal database for reliable operation. Furthermore, Windows Installer facilitates the principle of least privilege by performing software installations by proxy for unprivileged users.
Format
The term "format" has several meanings, related to 1) disk formatting, 2) page formatting, and 3) file formats.
1) Disk formatting
In order for storage media, such as a hard drive or flash drive to be recognized by your computer, it first needs to be initialized, or "formatted." Formatting a disk involves testing the disk and writing a new file system onto the disk. This enables the computer to read the disk's directory structure, which defines the way files and folders are organized on the disk.
You can use a disk utility program to format or reformat a disk. This will create a blank, empty disk for storing your files. Therefore, only format disks that don't contain important data or make sure you have backed up your data before reformatting a disk!
When you reformat a disk, it will appear to be empty. This is because the directory structure has been rewritten, making the entire disk space available for writing new data. However, the old files are still on the disk. They just don't show up since they are no longer included in the directory structure. So if you accidentally format a disk (which is pretty hard to do), you may be able to retrieve your files using a disk utility such as Norton Disk Doctor or DiskWarrior.
2) Page formatting
The term "format" can also be used to describe the page layout or style of text in a word processing document. When you format the layout of a page, you can modify the page size, page margins, and line spacing. When you format the text, you can choose the font and font size, as well as text styles, such as bold, underlined, and italics.
3) File formats
A file format refers to the way data is saved within a file. For example, some files are saved in a plain text format, while others are saved as binary files. Software developers often create proprietary file formats for their programs, which prevents the files from being used by other applications.
reyrsources;
http ~https://techterms.com/definition/windows
htt~~http://operatingsystemfundas.blogspot.com/2012/05/post1.html
~`yi~https://whatis.techtarget.com/definition/BIOS-basic-input-output-system
~G`~https://www.computerhope.com/jargon/s/startmen.html
`````~https://en.wikipedia.org/wiki/Windows_Installer
~~`~https://techterms.com/definition/format
w**Thanks for reading
~~`~https://techterms.com/definition/format
w**Thanks for reading
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