Good day all!
What is Operating System?
An operating system is a collection of system programs that control and coordinate the overall operations of a computer system. These programs act as an interface between the hardware and the application programs. The operating system has been described as the "traffic cop", "supervisor", or "office manager". The operating system manages the resources of the computer, namely, the CPU, Memory and Input/Output devices. The OS performs it's tasks without intervention; the user is usually unaware that the operating system is quietly at work assisting in various ways.
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Fig. 1.0 The systems programs within an operating system act as an interface among hardware, application programs, files and the user.
Functions performed by an operating system include:
- Providing for human computer interaction
- Booting process or starting the computer operation
- Scheduling jobs
- Controlling input and output operations
- Managing data and file storage
- Assigning different tasks to the CPU
- Providing security and control
Component Parts of an Operating System
An operating system is made up of "Control" and "Service" programs.
1) Control Programs: Control Programs permit user-computer communications, log jobs, and oversee the overall computer operation to ensure that the various activities run smoothly and to completion. The principal control program are:
- Command Processor
- Supervisor
- Interrupt handler
- Input Output control system.
2) Service Programs: Service programs perform a variety of labour-saving tasks and functions for the programmer. Whenever a specific task is required, the appropriate service program is accessed and executed by the operating system.
There are two types of service programs, they include:
- Utility programs, and
- Library programs.
Common Operating System Features
There are a multitude of operating system currently available. Some of them such as Disk Operating System (DOS) and the Macintosh operating system are designed for use with microcomputers, others, such as the IBM 4381 operating system, are implemented on large computer; and still others, such as UNIX, are used at all levels for microcomputers, minicomputer, and mainframes.
Some common features of operating system are discussed below:
1) Multiprogramming and Multitasking
In multiprogramming, several programs are placed in the computer's memory storage at the same time. The CPU then divides its time among these programs. It executes one program for a short period of time, then switches to another, and so forth, until each program is completed.
Multitasking is a variation of multiprogramming implemented on many high level ended microcomputers. It allows the user to access several programs at the same time. You can tell the computer to print a word processing file, sort a database file, and calculates spreadsheet simultaneously, for example.
Typically, multitasking is used to allow a single user to perform numerous tasks. Multiprogramming, however, is usually applied to situations in which several users want to access different applications at the same.
2) Multiprocessing
Multiprocessing involves linking two or more CPUs to optimize the handling of data. While one CPU is executing one set of instructions, another CPU can be executing a different set. This technique differs from multiprogramming, which executes only one program at a time but switches quickly between the different programs currently in memory. In Multiprocessing, the system can actually execute instructions and programs at the same time.
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Next time, I will bring to you the different types of Operating System! Thanks for enjoying my teaching, I will see you in my next one!
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