COSC1078 Introduction toInformation Technology: COSC1078 Introduction to Information Technology Bao Quoc Vo vqbao@cs.rmit.edu.au http://www.cs.rmit.edu.au/~vqbao 10.11.14


In today lecture …: In today lecture … Operating Systems Our focus Desktop Operating systems Microsoft Windows, Linux, MacOS Desktop applications


Operating Systems: Operating Systems An operating system (OS) is a set of computer programs that manage the hardware and software resources of a computer. At the foundation of all system software, an operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking, and managing file systems. Most operating systems have a command line interpreter as a basic user interface, but they may also provide a graphical user interface (GUI) for ease of operation.


OS interfaces: OS interfaces


Computer System Structure: Computer System Structure HARDWARE


Closer look to computer system: Closer look to computer system


Example (Simple Error Box): Example (Simple Error Box) Device Drivers APIs Application Software Kernel Call API Draw an error box with text 'Error' and 'OK' button Draw a gray and a blue box Draw a button Render 'OK' and 'Error' and display them Necessary Calculations Call the Kernel Memory locations for X and Y Low level basic logic


Operating Systems:Basic responsibilities and services: Operating Systems: Basic responsibilities and services Process management: Processes are running instances of programs on a computer. Modern operating systems enable concurrent execution of many processes at once via multitasking even with one CPU. Memory management: Modern computer's memory is arranged in a hierarchical manner: registers, CPU cache, random access memory and disk storage. An operating system coordinates the use of various types of memory by tracking which one is available, which is to be allocated or deallocated and how to move data between them.


Basic responsibilities and services: Basic responsibilities and services Disk and file systems: Files containing data and programs on a computer are organised into file systems and stored on storage devices, such as disks. Networking: Most current operating systems are capable of using some networking protocols to allow a computer to be connected to a network and enable resources, e.g. files, printer, scanners, etc. to be shared between different computers


Basic responsibilities and services: Basic responsibilities and services Security Graphical user interface Device drivers


OS Categories: OS Categories Operating Systems are divided into three Categories: Desktop Operating Systems Server Operating Systems Specialist Operating Systems


Desktop Operating Systems: Desktop Operating Systems Fairly reliable Kernel design Plug and Play Highly featured API User friendly Interface Popular Desktop Operating Systems Microsoft Windows Linux Apple MacOS X


Desktop OS Popularity: Desktop OS Popularity Microsoft Windows Linux and Others More than 85%


Linux: Linux


About Linux: About Linux Open Source Developed for the first time in 1991 by a Finnish student Written in C Red Hat, SUSE, Mandrake (Mandriva) Red Hat 7.1 has more than 30 million lines of source code GNOME and KDE LAMP (Linux, Apache, MySQL, Perl/PHP/Python) Routers and Firewalls Picture from Wikipedia


About Windows: About Windows Add-on to MS-DOS in 1985 Multi-tasking The Most Popular OS Security issues Windows Vista 2007 Picture from Wikipedia


About MacOS: About MacOS Macintosh Operating System Introduced by Apple in 1984 Graphical user interface (unlike MS-DOS) Unix Based MacOS X x86 (Jan 2006) Graphical features Picture from Wikipedia


Operating Systems (continued): Operating Systems (continued) Server Operating Systems Highly reliable Usually Microsoft Windows Server or Unix Specialist Operating Systems Mainframe operating systems, e.g. IBM’s z/OS Real-time scheduling embedded operating systems such as VxWorks, eCos, Palm OS, etc. Small size


Example of application software: Graphics & Design: Example of application software: Graphics andamp; Design