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The University of Akron Summit College Business Technology Department Computer Information Systems. 2440: 145 Operating Systems Introduction to UNIX/Linux Instructor: Enoch E. Damson. Operating System. The most important program running on a computer It helps: Store information
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The University of AkronSummit CollegeBusiness Technology DepartmentComputer Information Systems 2440: 145 Operating Systems Introduction to UNIX/Linux Instructor: Enoch E. Damson
Operating System • The most important program running on a computer • It helps: • Store information • Process data • Use application software • Access all hardware attached to a computer • Control all the computer’s resources • Provide the basis upon which application programs can be used or written Introduction to UNIX/Linux
Types of Operating Systems • Different computer systems can have different operating systems • For example: • Operating Systems for Desktop PCs • Microsoft Windows • Mac OS • Linux • Operating Systems for Server Computers • Microsoft Windows 2000 Server • Microsoft Windows Server 2003 • UNIX/Linux • NetWare • Mac OS X Server Introduction to UNIX/Linux
Types of Operating Systems… • Other operating systems include: • Operating Systems for Mainframes • IBMS’s MVS (Multiple Virtual Storage) • z/OS • Operating Systems for Network Servers • Novell NetWare • UNIX/Linux, Windows 2000/XP • Windows Server 2000 Introduction to UNIX/Linux
Types of Operating Systems… • Other operating systems include: • Operating Systems for Cellphones • Google Android • Symbian • Palm OS (HP WebOS) • RIM Blackberry OS • Apple iOS (iPhone) • Windows Mobile Introduction to UNIX/Linux
Operating System Components • Some of the components of operating systems include: • Application Programming Interface (API) – software designed to communicate with the application software and the user • Basic Input/Output System (BIOS) – provides the basic input/output functions to communicate with system devices, such as monitors, keyboard, disks, etc • Kernel – the core of the operating system that coordinates operating system functions, such as controlling memory and storage • Communicates with the BIOS, device drivers, and the API to perform these functions and also interface with the resource managers Introduction to UNIX/Linux
Operating System Components… • Other operating system components include: • Device drivers – programs that take requests from the API via the kernel and translate them into commands to manipulate specific hardware devices, such as disks, keyboards, monitors, printers, etc • Resource managers – programs that manage computer memory and central processor use • Optional drivers – for other functions and devices, such as sound Introduction to UNIX/Linux
Characteristics of Operating Systems • One way to look at a computer and operating systems is to consider them in terms of one or more of the following characteristics: • Single-tasking • Multi-tasking • Time-sharing • Batch processing • Real-time • Multiuser Introduction to UNIX/Linux
Single Tasking Systems • Executes only one process at a time • Generally restricted to microcomputers and certain specialized applications Introduction to UNIX/Linux
Multi-tasking Systems • Executes more than one program at a time for a user • It can run several programs in the background while users are working on another task in the foreground Introduction to UNIX/Linux
Time-sharing System • A central computer system that is used by multiple users and applications simultaneously • Mainframe computers typically fall into this category • Most of the work is done in batches or batch processes Introduction to UNIX/Linux
Batch Processing Systems • Execute programs (batch process) that do not require active user intervention • Normally uses a noninteractive I/O devices such as disks or document scanners for input and returns results to those same devices Introduction to UNIX/Linux
Real-time Systems • An operating system that interacts directly with the user and responds in real time (immediately or almost immediately) with required information • Windows XP and Mac OS X are examples of these systems Introduction to UNIX/Linux
Multi-user Systems • Supports multiple users who are accessing the computer’s and operating systems’ hardware and software facilities • Both time-sharing and real-time systems can be multiuser systems Introduction to UNIX/Linux
Operating Systems Platforms • The main operating system platforms include: • Windows: by Microsoft Corporation • Mac OS: by Apple • UNIX • Linux • Solaris Introduction to UNIX/Linux
The UNIX Operating System • Multiuser, multitasking operating systems with built-in network functions • Can be used on systems functioning as: • Dedicated servers in a server-based network • Client workstations connected to a server-based network • Client/server workstations connected to a peer-to-peer network • Standalone workstations not connected to a network • UNIX/Linux are: • Multiuser systems – allow many people simultaneous access and share the resources of a server computer • Portable – can be used in a variety of computing environments Introduction to UNIX/Linux
A Brief History of UNIX/Linux • Developed in the 1970s by a group of inventive scientists at Bell Laboratories. The created an operating system consisting of: • Kernel – main program to control the CPU and all other hardware • Utilities – a collection of user and system programs • Filesystem – a structure for keeping and locating data in files on the hard drive Introduction to UNIX/Linux
UNIX Versions • There are two major versions of UNIX: • AT&T UNIX version V • Berkeley UNIX Introduction to UNIX/Linux
Other UNIX Systems • There are several versions of UNIX running on Sun, HP, IBM, etc that are slightly different: • Linux • Solaris • UnixWare Introduction to UNIX/Linux
Linux • Linus Torvalds and other Internet accomplices wrote Linux (a UNIX look-alike OS) and made it available for free in its basic form • Versions of Linux include: • Ubuntu • OpenSolaris • Fedora • Red Hat • OpenSuse • Knoppix • Debian Introduction to UNIX/Linux
Linux Shells • Versions of UNIX shells include: • sh – Bourne shell (UNIX 7th Edition) • bash – Bourne-again shell (GNU) • tcsh – Popular extension of the C shell • csh – C shell (BSD) • jsh – Job control shell (SVR4) • ksh – Korn shell (Bell Labs) • rsh – Remote shell (TCP/IP) • zsh – Popular extension of the Korn shell Introduction to UNIX/Linux
Linux GUI Desktops • Mainstream desktop environments for Unix-like operating systems using the X Window System include: • KDE • GNOME • LXDE • Xfce Introduction to UNIX/Linux