Computer Systems Nat 4/5 Computing Science Operating Systems Lesson Aims By the end of this lesson: All pupils will be able to: Describe what an operating system is Describe what an application program is Describe the functions of an operating system Nat 4/5 Types of software There are two main types of software: Applications These are pieces of software that perform a particular task such as word processing or desktop publishing Systems Software (Operating Systems) These types of software control the running of hardware and the running of other software Nat 4/5 Applications Software Application software are programs that are designed to do a particular task. For example the Word Processor your revision notes were written in is an application program. Even games are application programs. Nat 4/5 Operating Systems An operating system is a piece of software that controls the operation of the systems hardware and the running of other software. Two of the more popular operating systems used at present are Microsoft® Windows Apple® OSX. Nat 4/5 Why is it important? You Which operating system do you write it for? IOS® Android ® Windows ® ? Why If are writing an app for a smartphone do you need to bear this in mind? I buy Office 2010 for windows – can I install it on a Mac? Nat 4/5 Operating Systems: Functions All operating systems have certain common functions: Provision of an Interface • This is the means of interacting with the user. Most modern operating systems provide a GUI (Graphical User Interface) Input Output • Controls the sending and receiving of data to and from peripherals Memory Management •Controls the systems RAM, controlling which locations in RAM programs are loaded into File Management • Controls where and how files are saved onto backing storage. Error Reporting • Providing useful feedback to users when errors do occur. Emulators An emulator is a utlility program which allows a computer to run a different operating system. This gets round the problem of not being able to run software because it has been written for a different operating system. An example is “Parallels Desktop” which allows an Apple computer to run Windows software Nat 4/5 Summary The Operating System (OS) of a computer is a program which manages the hardware and the running of other software on a computer system. The standard functions of an OS are: Provision of a human/computer interface Input/Output File Management (backing Storage) Memory management (RAM) Error Reporting Nat 4/5 Summary (2) An application program is a piece of software that performs a particular task such as games, word processers. An emulator is a utlility program which allows a computer to run a different operating system.