Programs that
control and direct the operation of the computer
Hardware are system software. System software consists of background programs that
enable application software to run smoothly. System Software includes:
Hardware are system software. System software consists of background programs that
enable application software to run smoothly. System Software includes:
Operating
System
Language
Processor
Utility
Program
Device
Drivers
Operating System
A computer is
simply a machine, developed by human beings to help do things to
other human beings. A computer only knows how to do a few (very few) little things.
If you want it to do something for you. all you need is to tell it. An operating system
is a program or a set of programs that controls and manages the other programs and
the operation of the computer. Operating system helps other programs to use the
hardware in a safe and controlling way. On all large computers and most micros, the
other human beings. A computer only knows how to do a few (very few) little things.
If you want it to do something for you. all you need is to tell it. An operating system
is a program or a set of programs that controls and manages the other programs and
the operation of the computer. Operating system helps other programs to use the
hardware in a safe and controlling way. On all large computers and most micros, the
operating system
is held on disk and has to be loaded into main memory once the
computer has been switched on, before any other programs can be run. The process of
loading the DOS system files into the computer’s memory is called Booting the System. The main files necessary to start up a computer are: IO.SYS, (Input/Output system file), MSDOS.SYS and the COMMAD.COM. The computer can be booted in one of the two ways:
computer has been switched on, before any other programs can be run. The process of
loading the DOS system files into the computer’s memory is called Booting the System. The main files necessary to start up a computer are: IO.SYS, (Input/Output system file), MSDOS.SYS and the COMMAD.COM. The computer can be booted in one of the two ways:
- Cold Booting : Booting a system by switching on the power, the computer reads its RAM space and searches for the DOS system files from disk drive(drive A: and drive C). As soon as it finds the system files, the DOS system files are loaded from the secondary media into the computer’s main memory is called cold booting.
- Warm Booting: A boot from power on by pressing CTRL+ALT+DEL key at the same time, the program in RAM gets deleted and searches for DOS system files and loads the system files into the main memory of the computer is called warm booting.
Human operators are not capable of
controlling the speed of today's computer without
the help of OS. Therefore the main role of OS can be said as resource management. The
primary resources it manages are:
the help of OS. Therefore the main role of OS can be said as resource management. The
primary resources it manages are:
- Processors
- Storage
- I/O Devices
- Data
- Programs
OS controls the way of using hardware by software. OS is in-between
hardware and
software. So software uses hardware with the help of OS. OS doesn't simply operate
computer but also does in a systematic, reliable and efficient manner.
software. So software uses hardware with the help of OS. OS doesn't simply operate
computer but also does in a systematic, reliable and efficient manner.
What an Operating System is not:
An operating
system is not:
• The hardware,
which provides the fundamental resources managed by the
operating system,
operating system,
• A programming
language, though a programming language is needed to write an
operating system.
operating system.
• A set of utility programs such as editors,
mailers, compilers and loaders, which
use the facilities provided by an operating system.
use the facilities provided by an operating system.
FUNCTIONS OF
OPERATING SYSTEM:
- The scheduling and loading of programs and subprograms to process and provide appropriate response to events.
- Controls over hardware and resources (e.g. Devices use for input, output or storage)
- Most multi-user systems provide the ability to assign login codes and passwords to different users for security purpose, (protecting hardware, software and datafrom improper use).
- Passing of control from one job (program) to another under the system of priority when more than one application program occupies main storage.
- Creation, updating, and deletion of files. A directory of files has to be maintained so that they can be quickly located when required.
- Furnishing (prepare) a complete record of all that happens during processing (usually in the form of a printed log)
- Communication with the computer operator usually by means of the Keyboard, mouse, printer etc. The operator communication with the operating system by means of a JCL (Job control Language), which is translated and executed by an interactive command interpreter.
- Most operating systems contain utility programs for the management, editing files. Recognizing disk space, making backups and so on.
What we see from
the OS is the human interface (or user interface) that takes care of us. The OS
allows us to communicate with the computer through many different means:
Keyboard,
screen, mouse, etc. by knowing how to handle each of these devices. It also
helps us (hut does not force us) to keep our information and data organized.
helps us (hut does not force us) to keep our information and data organized.
- Files / Documents
- Directories / Folders
- Disks / Archives'...
It also tries to make it easy for us to shape it to our own personal
taste, giving it our preferred look and feel, conforming it to suit our needs:
We can configure many aspects
of the functioning of the computer and how it will work (e.g. the kind of keyboard, or
language we are using, loudness of sounds, speed of mouse.etc.). And obviously we can tell it about the peripherals we are using and how we want it to communicate with them or handle them, and even about other computers, or remote resources so that it remembers our preferences and makes the computer work consistently as we like or need. In brief, what the operating system does is to provide an abstraction for programs (and hence for us) to access ail the computer resources in a simple and comfortable way,
hiding all the details of the underlying hardware. This way programs do not need to know about the specifics of the machine and can be simpler, saving a lot of work and space.
of the functioning of the computer and how it will work (e.g. the kind of keyboard, or
language we are using, loudness of sounds, speed of mouse.etc.). And obviously we can tell it about the peripherals we are using and how we want it to communicate with them or handle them, and even about other computers, or remote resources so that it remembers our preferences and makes the computer work consistently as we like or need. In brief, what the operating system does is to provide an abstraction for programs (and hence for us) to access ail the computer resources in a simple and comfortable way,
hiding all the details of the underlying hardware. This way programs do not need to know about the specifics of the machine and can be simpler, saving a lot of work and space.
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