1) Process management and Scheduling:
The operating system manages various peripherals and resources of the computer, user’s requests and commands, and schedules the job for the CPU to carry out in a sequence. It also handles sudden interrupt requirements and reschedules it accordingly.
2)Device Management:
There are two kinds of devices connected to a computer:
(1) Sharable devices such as discs, tapes and main memory enable many users simultaneously and dynamically to use them.
(2) Non-Shareable devices are printers, monitors, keyboards, card readers and other input/output devices such as mouse, scanner, plotter etc Non-shareable is so called because the device is for the exclusive use of one user at any given point of time.
The operating system monitors the availability and working conditions or status of these devices, as sharable or non-shareable and takes care of illegal instructions or commands and reports errors accordingly. The device management software, which forms a part of the operating system is called the BIOS (Basic Input Output Control System). For example, if the printer is not switched on or is not working the operating system reports, ‘Printer not ready’ and similar messages for discs or tape errors.
3) File and Data Management:
A user can have two kinds of files stored in the disc. It can be Programs and data or packages as files. In managing user programs and data files the operating system performs the following activities:
(1) Sets up directories and stores user files.
(2) Blocks and stores records
(3) Transfers main memory contents in specific filenames to discs and vice versa.
(4) Displays the name of files stored their size requests permission for overwriting or erasing and warnings such as space not available etc.
4) File Directory:
This refers to a table created by the operating system, where the list of filenames and their location in the floppy, hard disc, tape along with their size is stored for reference. The user needs to know only the name of the file and not its actual or physical location in the disc/tape or floppy.
5) Blocking and storing records:
The operating system logically partitions a media into blocks and then stores the records instead of allocating records to tracks and sectors serially. The operating system, stores records block by block and allocates physical location by dynamic blocking. The records are not stored serially from track 1 to the last track or from sector 1 to the last sector of a track. It stores randomly, but maintains the storage information in the lookup tables.
6) File Management:
In a multiuser system the access to the files are protected against tampering by unauthorized users. The hard disc, tapes and backup media, end users and system files storage and retrieval are all taken care of by the operating system.
7) Memory Management:
The available memory for processing such as accepting the keyboard and media inputs, storing intermediate results or output are all managed by the operating system. The operating system partitions the memory for different users and programs. In single user systems such as PC’s or workstations memory address and allocation is fixed but in a multiuser system memory allocation is dynamic.
8) Handling Users:
The operating system stores user passwords, access permissions provided for any files and directories and allocates disc space, execute commands, and manage single or multiple users simultaneously.
9) Command Interpretation and Execution:
The operating system reads the commands entered by the user, checks for errors, interprets and translates them to machine instructions and gets them executed by the hardware. Any error status is reported at the terminal. Every Operating System accompanying the hardware, has provision for executing user commands like copying, printing, renaming, deleting, listing etc.,
10) Job Accounting and Log Maintenance:
The operating system with the help of an internal time clock computes the time each resource (peripherals and CPU) is used by different users. It computes the lines printed, cards read , disc space, memory used, CPU time utilized etc. It also maintains a log and keeps track of the login and logout time of a particular user the commands entered by the user, files used and jobs carried out such as compiling, saving on hard disc or any other media printout etc.
11) Security:
In a single user system, the security generally provided is to physically lock up the system and media, to protect it from unauthorized access. The working files are saved in floppies or cartridge tapes and locked. Recently and of late add-on cards and software’s are available even for single user systems to incorporate password protection and security to prevent access.
In a multiuser environment, security protects one user from other by encrypting passwords and access permissions. File security and access permissions for owner, group and others, can be fixed at different modes such as read only , write only, execute only, etc., to enable access or non-access of file by various levels of users.
12) Communication:
Communication refers to the provision and facility provided to users to communicate with each other in the same system, or in another system, by sharing, transferring or downloading of programs and data files.
Multiuser systems provide interaction among different authorized users by forwarding and storing mails.
The console operator or system manager can send mail or messages to all the users currently logged in the system, either as general instructions or to warn users while shutting down the system, switching to single user mode etc., as the case may be.
13) Fault Tolerance Management:
In critical applications, fault tolerance management is built-in with the operating system, providing replication and dual hard discs. In the event of any interface or peripheral device failure, the system automatically switches over to the substitutes and keeps the process on without causing a breakdown. Instructions as to the nature of fault, and faulty devices is also displayed. This is achieved by incorporating parallel or duplicate devices redundantly. Disc mirroring for example, copies all files and programs in two discs and switches to one disc, if the other disc fails.
JAVA, C#, VB.6.0, SQL, C, Computer Sci Free Computer Programming Tutorials: http://bagadhicomputersciencetutorials.blogspot.com/
Thursday 30 June 2011
Functions of an Operating System.
1) Process management and Scheduling:
The operating system manages various peripherals and resources of the computer, user’s requests and commands, and schedules the job for the CPU to carry out in a sequence. It also handles sudden interrupt requirements and reschedules it accordingly.
2)Device Management:
There are two kinds of devices connected to a computer:
(1) Sharable devices such as discs, tapes and main memory enable many users simultaneously and dynamically to use them.
(2) Non-Shareable devices are printers, monitors, keyboards, card readers and other input/output devices such as mouse, scanner, plotter etc Non-shareable is so called because the device is for the exclusive use of one user at any given point of time.
The operating system monitors the availability and working conditions or status of these devices, as sharable or non-shareable and takes care of illegal instructions or commands and reports errors accordingly. The device management software, which forms a part of the operating system is called the BIOS (Basic Input Output Control System). For example, if the printer is not switched on or is not working the operating system reports, ‘Printer not ready’ and similar messages for discs or tape errors.
3) File and Data Management:
A user can have two kinds of files stored in the disc. It can be Programs and data or packages as files. In managing user programs and data files the operating system performs the following activities:
(1) Sets up directories and stores user files.
(2) Blocks and stores records
(3) Transfers main memory contents in specific filenames to discs and vice versa.
(4) Displays the name of files stored their size requests permission for overwriting or erasing and warnings such as space not available etc.
4) File Directory:
This refers to a table created by the operating system, where the list of filenames and their location in the floppy, hard disc, tape along with their size is stored for reference. The user needs to know only the name of the file and not its actual or physical location in the disc/tape or floppy.
5) Blocking and storing records:
The operating system logically partitions a media into blocks and then stores the records instead of allocating records to tracks and sectors serially. The operating system, stores records block by block and allocates physical location by dynamic blocking. The records are not stored serially from track 1 to the last track or from sector 1 to the last sector of a track. It stores randomly, but maintains the storage information in the lookup tables.
6) File Management:
In a multiuser system the access to the files are protected against tampering by unauthorized users. The hard disc, tapes and backup media, end users and system files storage and retrieval are all taken care of by the operating system.
7) Memory Management:
The available memory for processing such as accepting the keyboard and media inputs, storing intermediate results or output are all managed by the operating system. The operating system partitions the memory for different users and programs. In single user systems such as PC’s or workstations memory address and allocation is fixed but in a multiuser system memory allocation is dynamic.
8) Handling Users:
The operating system stores user passwords, access permissions provided for any files and directories and allocates disc space, execute commands, and manage single or multiple users simultaneously.
9) Command Interpretation and Execution:
The operating system reads the commands entered by the user, checks for errors, interprets and translates them to machine instructions and gets them executed by the hardware. Any error status is reported at the terminal. Every Operating System accompanying the hardware, has provision for executing user commands like copying, printing, renaming, deleting, listing etc.,
10) Job Accounting and Log Maintenance:
The operating system with the help of an internal time clock computes the time each resource (peripherals and CPU) is used by different users. It computes the lines printed, cards read , disc space, memory used, CPU time utilized etc. It also maintains a log and keeps track of the login and logout time of a particular user the commands entered by the user, files used and jobs carried out such as compiling, saving on hard disc or any other media printout etc.
11) Security:
In a single user system, the security generally provided is to physically lock up the system and media, to protect it from unauthorized access. The working files are saved in floppies or cartridge tapes and locked. Recently and of late add-on cards and software’s are available even for single user systems to incorporate password protection and security to prevent access.
In a multiuser environment, security protects one user from other by encrypting passwords and access permissions. File security and access permissions for owner, group and others, can be fixed at different modes such as read only , write only, execute only, etc., to enable access or non-access of file by various levels of users.
12) Communication:
Communication refers to the provision and facility provided to users to communicate with each other in the same system, or in another system, by sharing, transferring or downloading of programs and data files.
Multiuser systems provide interaction among different authorized users by forwarding and storing mails.
The console operator or system manager can send mail or messages to all the users currently logged in the system, either as general instructions or to warn users while shutting down the system, switching to single user mode etc., as the case may be.
13) Fault Tolerance Management:
In critical applications, fault tolerance management is built-in with the operating system, providing replication and dual hard discs. In the event of any interface or peripheral device failure, the system automatically switches over to the substitutes and keeps the process on without causing a breakdown. Instructions as to the nature of fault, and faulty devices is also displayed. This is achieved by incorporating parallel or duplicate devices redundantly. Disc mirroring for example, copies all files and programs in two discs and switches to one disc, if the other disc fails.
The operating system manages various peripherals and resources of the computer, user’s requests and commands, and schedules the job for the CPU to carry out in a sequence. It also handles sudden interrupt requirements and reschedules it accordingly.
2)Device Management:
There are two kinds of devices connected to a computer:
(1) Sharable devices such as discs, tapes and main memory enable many users simultaneously and dynamically to use them.
(2) Non-Shareable devices are printers, monitors, keyboards, card readers and other input/output devices such as mouse, scanner, plotter etc Non-shareable is so called because the device is for the exclusive use of one user at any given point of time.
The operating system monitors the availability and working conditions or status of these devices, as sharable or non-shareable and takes care of illegal instructions or commands and reports errors accordingly. The device management software, which forms a part of the operating system is called the BIOS (Basic Input Output Control System). For example, if the printer is not switched on or is not working the operating system reports, ‘Printer not ready’ and similar messages for discs or tape errors.
3) File and Data Management:
A user can have two kinds of files stored in the disc. It can be Programs and data or packages as files. In managing user programs and data files the operating system performs the following activities:
(1) Sets up directories and stores user files.
(2) Blocks and stores records
(3) Transfers main memory contents in specific filenames to discs and vice versa.
(4) Displays the name of files stored their size requests permission for overwriting or erasing and warnings such as space not available etc.
4) File Directory:
This refers to a table created by the operating system, where the list of filenames and their location in the floppy, hard disc, tape along with their size is stored for reference. The user needs to know only the name of the file and not its actual or physical location in the disc/tape or floppy.
5) Blocking and storing records:
The operating system logically partitions a media into blocks and then stores the records instead of allocating records to tracks and sectors serially. The operating system, stores records block by block and allocates physical location by dynamic blocking. The records are not stored serially from track 1 to the last track or from sector 1 to the last sector of a track. It stores randomly, but maintains the storage information in the lookup tables.
6) File Management:
In a multiuser system the access to the files are protected against tampering by unauthorized users. The hard disc, tapes and backup media, end users and system files storage and retrieval are all taken care of by the operating system.
7) Memory Management:
The available memory for processing such as accepting the keyboard and media inputs, storing intermediate results or output are all managed by the operating system. The operating system partitions the memory for different users and programs. In single user systems such as PC’s or workstations memory address and allocation is fixed but in a multiuser system memory allocation is dynamic.
8) Handling Users:
The operating system stores user passwords, access permissions provided for any files and directories and allocates disc space, execute commands, and manage single or multiple users simultaneously.
9) Command Interpretation and Execution:
The operating system reads the commands entered by the user, checks for errors, interprets and translates them to machine instructions and gets them executed by the hardware. Any error status is reported at the terminal. Every Operating System accompanying the hardware, has provision for executing user commands like copying, printing, renaming, deleting, listing etc.,
10) Job Accounting and Log Maintenance:
The operating system with the help of an internal time clock computes the time each resource (peripherals and CPU) is used by different users. It computes the lines printed, cards read , disc space, memory used, CPU time utilized etc. It also maintains a log and keeps track of the login and logout time of a particular user the commands entered by the user, files used and jobs carried out such as compiling, saving on hard disc or any other media printout etc.
11) Security:
In a single user system, the security generally provided is to physically lock up the system and media, to protect it from unauthorized access. The working files are saved in floppies or cartridge tapes and locked. Recently and of late add-on cards and software’s are available even for single user systems to incorporate password protection and security to prevent access.
In a multiuser environment, security protects one user from other by encrypting passwords and access permissions. File security and access permissions for owner, group and others, can be fixed at different modes such as read only , write only, execute only, etc., to enable access or non-access of file by various levels of users.
12) Communication:
Communication refers to the provision and facility provided to users to communicate with each other in the same system, or in another system, by sharing, transferring or downloading of programs and data files.
Multiuser systems provide interaction among different authorized users by forwarding and storing mails.
The console operator or system manager can send mail or messages to all the users currently logged in the system, either as general instructions or to warn users while shutting down the system, switching to single user mode etc., as the case may be.
13) Fault Tolerance Management:
In critical applications, fault tolerance management is built-in with the operating system, providing replication and dual hard discs. In the event of any interface or peripheral device failure, the system automatically switches over to the substitutes and keeps the process on without causing a breakdown. Instructions as to the nature of fault, and faulty devices is also displayed. This is achieved by incorporating parallel or duplicate devices redundantly. Disc mirroring for example, copies all files and programs in two discs and switches to one disc, if the other disc fails.
Subscribe to:
Posts (Atom)