system SOFTWARE

Brain Teaser What is an operating system? List some types of operating system What do you think are the functions of an operating system? What do you think are software utilities? What do you think are the purpose of software utilities?

What is an operating system? An Operating System (commonly abbreviated OS and O/S) is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the limited resources of the computer. An operating system is a program designed to run other programs on a computer Operating systems are responsible for everything from the control and allocation of memory to recognizing input from external devices and transmitting output to computer displays.

Discussion What are the functions of the operating system?

Functions of the OS It manages the sharing of internal memory among multiple applications It handles input and output to and from attached hardware devices, such as hard disks, printers and dial-up ports. It sends messages to the applications or interactive users (or to a system operator) about the status of operations and any errors that may have occurred. It can offload the management of what are called batch jobs (for example, printing) so that the initiating application is freed from this work

CLASSIFICATION OF OS Multi-user: Allows two or more users to run programs at the same time. Some operating systems permit hundreds or even thousands of concurrent users. Multiprocessing: Supports running a program on more than one CPU Multitasking: Allows more than one program to run concurrently Multithreading: Allows different parts of a single program to run concurrently Real time: Responds to input instantly. General-purpose operating systems, such as DOS and UNIX, are not real-time.

Discussion List some types of operating system What are the advantages and disadvantages of using the operating system you have listed?

TYPES OF OPERATING SYSTEM Microsoft Disk Operating System (MSDOS) Windows 3.x Windows 95 OPERATING SYSTEM 2 (OS/2) UNIX Operating System APPLE MACINTOSH (MAC OS)

Microsoft Disk Operating System (MSDOS This is a single user, single processing operating system created by Microsoft for use in personal computers. MSDOS uses a command-driven interface.

Advantage of MSDOS Once the commands are known, MSDOS is the OS of choice because of the speed at which tasks can be performed

Disadvantages of MSDOS MSDOS is command-driven; therefore it is not very user friendly. The user has to memorize all the commands or constantly refer to a command manual. It is a single user, single tasking operating system i.e. it only facilitates the running of one program at a time.

Windows 3.X This is a GUI based operating environment created by Microsoft. This operating environment uses MSDOS as the platform on which it operates. Thus it was usually called “DOS with windows”. This software is no longer on the market

Advantages of Windows 3.X It allows for multitasking capability It has dynamic data exchange function. Dynamic data exchange allows one program to access data from another program that is currently running. It provides a GUI making it very user friendly. User are able to use icons or pull down menus, mouse, pointers

Disadvantages of Windows 3.X It does not work well in a network environment It can handle multitasking, but it is really switching between tasks. If the program does not go back to a task quickly enough data can be lost.

WINDOWS 95 Windows 95 is an upgrade of windows 3.X. MSDOS is integrated into the software making it one complete system.

Advantages of Windows 95 Windows 95 is a multitasking operating system Graphical user interface makes it easy to use and easier to learn It provides compatibility with existing windows and DOS programs It works efficiently in “single user’ (stand alone) environment as well as in a network environment

Disadvantage of Windows 95 Windows 95 does not realise its full potential when running 16 bit applications

Operating System 2 (OS/2) Operating System 2 (OS/2) is a single user, multitasking operating system with a graphical user interface. It provides a dual boot feature that allows a user to boot up in either DOS or OS/2

Advantages of OS/2 It’s a multitasking operating system with both single user and network capabilities It supports disk drives as large as 256gigs

Disadvantages of OS/2 OS/2 interface is similar to that of Windows so it might take a while to adjust to some of the differences. Compared to Windows, there are not as much application software available

UNIX Operating System UNIX was first developed in 1969 by K. Thompson, R. Canaday, and D. Ritchie for minicomputers. UNIX is a multiuser, multitasking system that runs on many different computer systems from microcomputer to mainframe.

Advantages of UNIX UNIX is portable i.e. it can be used with many different types of computers, from microcomputers to supercomputers. It is a multiuser and multitasking operating system Networking is another strong feature of a UNIX operating system. UNIX can be connected through several different kinds of equipment and can share files among them.

Disadvantages of UNIX UNIX is a difficult software for novice microcomputer users to understand Limited amount of application programs are available for UNIX It is not standardized, therefore an application program written for one UNIX system might not work with another.

APPLE MACINTOSH (MAC OS) The Apple Macintosh is a multitasking operating system that was the first graphical user interface to achieve commercial success The Macintosh operating system has two (2) major files. They are the System files and the Finder The system file manages the user interface. Both files work together to achieve the operating system procedures such as formatting disks, copying files and running application programs.

Advantages of MAC OS It provides high quality graphics processing that makes Macintosh popular for desktop publishing. The Apple Mac is easy to use

Disadvantage of MAC OS Macintosh operating system is incompatible with DOS and Windows PC applications.

What is software utilities? is a type of computer software It is specifically designed to help manage and tune the computer hardware, operating system or application software, and perform a single task or a small range of tasks; as opposed to application software which tend to be software suites

Software Utilities cont’d The System Utilities directory includes a variety of PC utilities for managing and optimizing your computer system, including the Registry, start-up applications, desktop, and other settings The software in this catalogue may clean your local drives, create backups and recover lost files, improve system performance, securely delete documents, and monitor your hardware.

Class Activity Define the term operating system List four functions of the operating system List four types of operating system, giving a brief description of each Give one example of an operating system that uses a command driven interface

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