Presentation on theme: "Operating Systems: Software in the Background"— Presentation transcript:
1 Operating Systems: Software in the Background Chapter 2Operating Systems: Software in the Background
2 Types of Software Systems software Application software programs related to coordinating computer operationsincludes operating systems, language translators, and utility programsApplication softwaresoftware designed to accomplish a specific taskincludes word processors, electronic spreadsheets, etc.
3 What is an operating system? The OS is a set of programs that controls access to the hardware and software resources of the computer.kernel - the part of the OS that supervises the overall operation of the OSresident when computer is on (stored in main memory)
4 Booting the systemWhen the computer it turned on, the resident portions of the OS must be loaded into main memory from the hard disk.A small program in ROM makes internal hardware checks then starts the booting process.
5 Popular operating systems PC’sMS WindowsMac OSLinux - Unix-like system for PC’sMultiuser systemsUnix - not tied to a specific platform, primary OS for the Internet
6 Terms platform - combination of hardware and OS used by a computer software is designed for a specific platformprompt - a signal displayed on screen to indicate that the system is waiting for a command or inputicon - a picture that represents a program, hardware device, or data object (file)
7 More termsmenu - a list of options from which a command can be selectedoperating environment (shell) - a program that overlays a program (often an OS) to provide a more user friendly interface
8 Operating System Functions Management of the computer’s hardware resourcesmultiprogramming - single CPU runs two or more programs concurrentlytime sharing - special form of multiprogramming in which each user is allotted a time slicemultiprocessing - multiple CPUs run programs simultaneouslyvirtual memory - currently active part of program in memory, the rest on disk, swapped in and out as needed
9 Operating System Functions Execution and provision of services for application softwareproviding access to peripheralsspooling - print jobs are written temporarily to disk until the printer is readyretrieval of files for useallocating space for and storing files
10 Operating System Functions Establishment of a user interface - the way a user communicates with a program2 major types for operating systemscommand line interfacetext-based, older, harder to learnMS-DOS, Unix, Linuxgraphical user interfaceuse icons and menus to allow command input, popular interface for PC’s, easy to learnWindows, Mac OS
11 Utility programs some may be included with the OS file manager - organizes files for easy accessprovides the ability to display, copy, name, delete, and move filesformat and copy disksbackup and restoreduplication of important materials for safe storage
12 More utility programs disk defragmentation file compression reorganization of files on disk to improve system performancefile compressionprograms to reduce the size of files for storage or transmission purposesdevice driverprogram that makes it possible for the OS to communicate with peripheral devices