Computer Operating systems

An operating system, or “OS”, is software that communicates with the hardware and allows other programs to run. An operating system is a software that manages the computer hardware and provides common services for execution of various application software operating system acts as an intermediary between application programs and the computer hardware. An operating system is the program that after being loaded into the computer by a boot program, manages all the other programs in a computer.

OBJECT 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.

EVALUATION:

1. Define operating system
2.  Mention the objectives of OS.

TYPES OF OPERATING SYSTEM

1. Single user operating system
2. Multi – user operating system
3. Multi – tasking operating system
4. Distributed operating system
5. Batch processing operating system
6. Real – time operating system
7. Command based OS
8. Network operating system
9. GUI

1. Single – User Operating System: A single user operating system is an operating system that is designed to manage the computer resource and allocates them to one user. Examples are MS – DOS, Some versions of windows operating system etc.
2. Multi – User Operating System:  is an operating system that allows access by multiple users of a computer. This operating system allows more than one user to run several programs at the same time. The process of running more than one program concurrently or at the same time is known as multiprogramming. Examples are : UNIX, XENIX etc.
3. Multi – Tasking Operating System: this type of OS, several application maybe simultaneously loaded and used in the memory.

While the processor handles only one application at a particular time, it is capable of switching between the applications effectively to apparently execute each application. Examples are all windows operating system.

• Distributed Operating System: In a distributed system, software and data may be distributed around the system, programs and files may be stored on different storage devices which are located in different geographical locations and maybe accessed from different computer terminals.
• Batch Processing Operating System: In a batch process operating system, interaction between the user and processor is limited or there is no interaction at all during the execution of work. Data and programs that need to be processed are bundled and collected as a “batch” and executed together. Batch processing operating systems are ideal in situation where:
• There are large amounts of data to be processed.
• Similar processing is involved when executing the data.

• Real – Time Operating System: A real time OS processes inputs simultaneously, fast enough to affect the next input or process. It is used to control complex systems that require a lot of processing like machinery and industrial systems.
• Dos: It is operating system software used in most computers that provides the abstraction and management of secondary storage devices and the information on them.
• GUI (Graphical User Interface): operating systems of this class have interactive features which make them user friendly, easier to use, etc. examples are: Ms Windows, Linus etc.
• Network Operating System: A network operating systems links computers and users together to share resources and communicate with one another. Common examples includes: windows NT, Windows server 2003 etc.

In summary, operating system can be categorized into two, namely:

1. Command based operating system.
2. Graphical user interface (GUI)

Each of the types of operating system either falls under command based operating system or Graphical user interface (GUI).

EXAMPLES OF OPERATING SYSTEM

Common examples of operating system

1. Ms Windows (Microsoft window):   It is a single user GUI operating system. That is, only one person can use the system at a time.

Versions of windows operating system:

1. Windows 95
2. Windows 98
3. Windows 2000
4. Windows ME ( millennium edition)
5. Windows XP ( Experience)
6. Windows NT ( New Technology)
7. Windows Vista
8. Windows 7
9. Windows 8
10. Windows 10

2. UNIX ( A multiuser command line operating system)
3. Novell Netware  (is a command line Network Operating System)
4. Linux:  A GUI/ Command li ne multiuser and network operating system.
5. XENIX:  A Unix based multiuser operating system.
6. MS DOS  ( Microsoft Disk operating system):  This is a single user operating system.

FUNCTIONS OF OPERATING SYSTEM

Operating system performs the following functions:

1. Storage Management: Operating system also controls all the storage operations. This means how the data or files will be stored intro the computers and how the file will be accessed by the users etc. Creation of files, Directories.  Basically, operating  system performs the following :
2. It allows creation of files and directories.
3. It allows the reading of data from and writing of data to files and directories.
4. It copies the contents of the files and directories from one place to another.

• Process Management:  The operating system also treats the process management. That is, it is the duty of operating system to handle processes given it by the users; the system own process as well.
• Memory Management:  It manages the sharing of internal memory among multiple applications. E.g Primary Memory :  RAM , ROM ;  Secondary Memory :  Hard disc, CD,  DVD  etc.
• Resources Management:   Operating system manages all the resources of the computer system. Both the hardware ( Input, Output and Peripheral) and the software resources.
• Security Management:  these include: Virus management, Alert messages, passwords, Access protection etc.
• Load and run application software:  the operating system determines which application should run in what order and how much time should be allowed for each application before giving another application a turn.

EVALUATION

1. Define operating system.
2. State six functions of operating system.

GENERAL EVALUATION:

1. What is operating system?
2. List functions of operating system.
3. What do you understand by memory management?
4. Without operating system, what would happen to a computer?

READING ASSIGNMENT

Hiit @ Schools, Data Processing for Senior Secondary Education, pgs 31 – 32.

WEEKEND ASSIGNMENT

1. Which function of operating system deals with the creation of files and directories.  A.  Memory management  B.  Resources management   C.  Storage management   D.  All of the above
2. Control of the right and access to file is ………  function of  O.S.  A.  Memory management   B.  Resources management    C.  Storage management   D.  Process management
3. ……… handles processes in computer.  A.  DBMS    B.  O.S    C.  Software    D.   Hardware
4. The …….. part of a computer is synchronized to perform tasks.   A.   Monitor   B.   Keyboard   C.   CPU    D.   System unit
5. The hardware part of computer has ………   A.   2    B.   3   C.   5    D.   7

THEORY

1. Explain the security management functions of operating system.

Mention four examples of secondary memory.

EVALUATION:

1. Mention Eight versions of windows operating system.
2. What is the full meaning of GUI?

GENERAL EVALUATION :

1. State the full meaning of :  Windows XP,  Windows NT.
2. What is the difference between GUI and Command based operating system?
3. Mention the latest version of windows operating system.
4. The full meaning of Ms DOS is  ………

READING ASSIGNMENT

Hiit @ Schools Data Processing for Senior Secondary Education, pg 27.

WEEKEND ASSIGNMENT

1. Windows ME stands for  …….  A.  More experience   B.  Millennium Edition   C.   More Millennium    D.  None of the above
2. In windows NT, NT there stands for ……….  A.  New technology   B.  New Technical   C.  Now Technology   D.   Non Technology
3. ‘XP’ in windows XP stands for ……….   A.  Professional   B.  Exceptional   C.  Experience   D.   Expert
4. DOS stands for  ………  A.  Disk operating system   B.   Do operating system   C.  Disk open system   D.  Diskette operating system
5. ……… is an example of windows command line operating system.   A.   Novell   B.   Ms DOS   C.  Linux   D.   XENIX

THEORY

1. List the different versions of  windows operating system.
2. Give any two examples of GUI/Command line multiuser operating system.

GENERAL EVALUATION

1. List the types of operating system.
2. What is operating system?
3. Differentiate between command based operating system and GUI
4. What do you understand by batch processing operating system?
5. State the objectives of OS.

READING ASSIGNMENT

HIIT (a) School Data processing for senior secondary Education, pages 30 – 32.

WEEKEND ASSIGNMENT

1. Types of operating system can be categorized into ………… A. 4 B. 2 C. 3 D. 7
2. ………. type of OS processes input simultaneously. A. Dos B. Real – time C. GUI        D. Single – user OS
3. The operating system fits for computer networking is ……… A.  Single user B. multi user C.  Real – time D.  Batch processing
4. ………helps us in loading programs into the computer. A.  Hardware B.  software

C.  Operating system D.  DBMS

• Example of the command based operating system is ………. A.  Single – user

B.  GUI  C.  Dos     D.  Batch processing

THEORY

1. What is operating system?
2. List various types of