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Systems Software The Power Behind the power Yuh-Jzer Joung Systems Software User Applications Software word processing, spreadsheet, communications, database, etc. External utility program Systems software Operating System Language translators Hardware (computer plus peripheral devices) Yuh-Jzer Joung Systems Software The Operating System The operating system consists of the master system of programs that manage the basic operations of the computer. • Booting • Housekeeping tasks • User interface • Managing computer resources • Managing files • Managing tasks Yuh-Jzer Joung Systems Software Operating System vs. Operating Environment An operating environment is a user interface built on top of an operating system. It is often a graphical user interface or a menudriven interface. E.g., Windows 3.1 on top of DOS. Hardware Yuh-Jzer Joung Systems Software Booting The operating system begins to operate as soon as you turn on, or “boot,” the computer. The term booting refers to the process of loading an operating system into computer’s main memory from diskette or hard disk. Housekeeping Tasks Perform common repetitious “housekeeping tasks” such as formatting a diskette. User Interface The user interface is the part of the operating system that allows you to communicate, or interact, with it. Yuh-Jzer Joung Systems Software User Interface C:\>VER • Command-driven: requires you to enter a command by typing in codes or words. MS-DOS Version 6.22 • Menu-driven: allows you to choose a command from a menu. C:\>_ • Graphical: the graphical user interface (GUI) uses images to represent options. Icons are small pictorial figures that represent tasks, functions, or programs. Close… File Edit View Layout Tool Open… Save… Ctrl+F12 Save As... F10 (C:) Yuh-Jzer Joung Systems Software Shft+F10 (D:) (E:) Friendly interfaces Some microcomputer makers provide interface software that uses familiar objects or cartoon characters in order to make systems software easy for novices to use . Yuh-Jzer Joung Systems Software Managing Computer Resources Behind the user interface, the operating system acts like a police officer directing traffic. This activity is performed by the supervisor, or kernel, the central component of the operating system. The supervisor, which manages the CPU, resides in main memory while the computer is on and directs other programs to perform tasks to support applications programs. Managing Tasks Among the ways operating systems manage tasks in order to run more efficiently are multitasking, multiprogramming, time sharing, and multiprocessing. Yuh-Jzer Joung Systems Software Managing Tasks • Multitasking: executing more than one program concurrently. • Multiprogramming: concurrent execution of different users’ programs. • Time-sharing: round-robin processing of programs for several users. The key to time-sharing is time slicing. • Multiprocessing: simultaneous processing of two or more programs by multiple computers. Two approaches: --- co-processing --- parallel processing. Yuh-Jzer Joung Systems Software Microcomputer Operating Systems & Operating Environments • • • • • DOS Macintosh System 7.X Windows 3.X for DOS OS/2 Warp Windows 95/98 Yuh-Jzer Joung • • • • Windows NT Unix NetWare Coming attractions Systems Software DOS-for Disk Operating System-runs primarily on IBM and IBM-compatible microcomputers Microsoft’s MS-DOS: The”MS” stands for Microsoft. Microsoft launched its original version, MSDOS 1.0, in 1981 and there have been several upgrades since then. IBM’s PC-DOS: The”PC” stands for Personal Computer. The most recent version is PC-DOS 7, released March 1995. Yuh-Jzer Joung Systems Software For the love of Mac The icons, pull-down menus, and windows of the Apple Macintosh System 7 operating system give the Mac a look and feel that makes many users say they love their machines. Yuh-Jzer Joung Systems Software Windows for DOS Windows is an operating environment made by Microsoft that lays a graphical user interface shell around the MS-DOS or PC-DOS operating system . Yuh-Jzer Joung Systems Software Windows 95 & Later Windows 95, the successor to Windows 3.1 for DOS, is a true operating system for IBM-style personal computers rather just an operating environment . • • • • • • Clean “start” Better menus Long file names The “Recycle Bin” 32-bit instead of 16-bit Plug and play (PnP) Yuh-Jzer Joung Systems Software Windows NT • Unveiled by Microsoft in May 1993, Windows NT, for New Technology, is an operating system intended to support large networks of computers. • Primary designed to run on the more powerful microprocessors, both Intel’s Pentium and Motorola’s PowerPC. • Use client/server architecture. Yuh-Jzer Joung Systems Software Unix • Developed at AT&T Bell Lab in the 1960s. AT&T then has licensed Unix to many Universities and companies, producing several versions of Unix. • Unix is an operating system for multiple users and has built-in networking capability, the ability to run multiple tasks at one time and versions that can run on all kinds of computers. • Is “portable” because it can run with relatively simple modifications on different types of computers. • Recent versions, BSD4.1.3, Solaris, Linux, FreeBSD, ... Yuh-Jzer Joung Systems Software NetWare • Developed by Novell during the 1980s, NetWare has become the most popular operating system for coordinating microcomputer-based local area network (LAN) throughout a company or campus. • Allows remote disks to be accessed as local disk (like C:\>, D:\>, F:\> ). • Microsoft is trying to beat NetWare with its Windows NT. Yuh-Jzer Joung Systems Software Operating System Types of Microprocessors Single User Intel 8088,8086, Yes 80286,80386 80486,Pentium Macintosh Motorola 8030, Yes System 8040,68030, Software 68040,PowerPC Windows3.1 Intel 80286,80386, Yes 80486,Pentium OS/2 Intel 80286,80386, Yes 80486,Pentium, PowerPC Windows95 Intel 80386,80486, Yes Pentium WindowsNT Intel 80386,80486, Pentium,PowerPC, DEC Alpha RISC Unix Almost all processors NetWare Yuh-Jzer Joung Intel 80386,80486,Systems Software Pentium Multitask Multiuser MS-DOS PC-DOS Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes External Utility Programs External utility programs are special programs that provide specific useful services not performed or performed less well by other systems software programs. Examples include: • • • • • • • Screen saver Data recovery Backup Virus protection File defragmentation Data compression Memory management Yuh-Jzer Joung Systems Software • Virus protection: A virus consists of hidden programming instructions that are buried within an applications or systems program. They copy themselves to other programs, causing havoc. Fortunately , anti-virus software is a utility program that scans hard disks, diskettes, and the microcomputer’s memory to detect viruses. • File defragmentation: Fragmentation is the scattering of portions of files about disk in non-adjacent areas, thus greatly slowing acess to the files. • Memory management : Memory-management utilities are programs that determine how to efficiently control and allocate memory resources. They may be activated by software drivers. A driver is a series of program instructions that standardizes the format of data transmitted between a computer and a peripheral device . Yuh-Jzer Joung Systems Software Personal computing today Provided by online services User’s responsibility: Purchasing, installing, upgrading, using Applications software Data Data Personal computer Operating system software Applications software Data Applications software Data Applications software Yuh-Jzer Joung Systems Software Data Personal computing tomorrow User’s responsibility Provided by online services Purchasing,using Applications software Personal computer Universal browser Applications software Applications software Data Data Data Data Applications software Yuh-Jzer Joung Systems Software Data Bloatware or the network computer • • • • • • Would the browser really become the OS? Would communications functions really take over? Would an NC really be easy to use? Aren’t high-speed connections required? Doesn’t the NC run counter to computing trends? Would users go for it? Yuh-Jzer Joung Systems Software