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System Software Chapter 5 The Director © The McGraw-Hill Companies, Inc., 2000 Overview • System software • Applications software • System software components • Platforms • Web and Java Ch 5 © The McGraw-Hill Companies, Inc., 2000 2 CCI What is system software and applications software? Ch 5 © The McGraw-Hill Companies, Inc., 2000 3 CCI System Software • Works behind the scene – starts up computer – provides interface between the machine language the computer understands and hardware and applications – system software must be loaded into RAM at start up Ch 5 © The McGraw-Hill Companies, Inc., 2000 4 CCI Applications Software • Designed for user’s requirements – – – – – Ch 5 word processing spreadsheets database management graphics multimedia © The McGraw-Hill Companies, Inc., 2000 5 CCI Applications Software • Productivity software – word processing, spreadsheet, financial management, database management, communications, suites, browsers • • • • Ch 5 Business/specialty software Education reference software Home/personal software Entertainment software © The McGraw-Hill Companies, Inc., 2000 6 CCI Applications Software • Has a user interface – communicates with other software components such as the operating systems and application programming interface • communicating to hardware Ch 5 © The McGraw-Hill Companies, Inc., 2000 7 CCI Determine Needs Before Buying • What applications software do you use? – – – – – – word processing browser multimedia graphics financial management database management • Choose a computer system based on software requirements Ch 5 © The McGraw-Hill Companies, Inc., 2000 8 CCI System Software Components • What functions does system software perform? Ch 5 © The McGraw-Hill Companies, Inc., 2000 9 CCI Basics • Interprets data and instructions • Communicates with peripherals • Manages files Ch 5 © The McGraw-Hill Companies, Inc., 2000 10 CCI System Software Components • Operating system • Utilities • Language translators Ch 5 © The McGraw-Hill Companies, Inc., 2000 11 CCI OS • Master programs – supervisor in RAM – auto loads during boot routine using the master boot record on the primary hard disk – POST performed • Software interfaces to hardware frequently remain resident • BIOS manages keyboard, screen, drives, ports, time, and date Ch 5 © The McGraw-Hill Companies, Inc., 2000 12 CCI OS • BIOS stored on one or more ROM chips • Later editions of BIOS may be flash updated according to motherboard manufacturer’s instructions Ch 5 © The McGraw-Hill Companies, Inc., 2000 13 CCI Managing Programs and Data • Multitasking (single user) – concurrent program running – foreground and background running • Multiprogramming (multi-user) – concurrent use by different users Ch 5 © The McGraw-Hill Companies, Inc., 2000 14 CCI Managing Programs (continued) • Time-sharing – time slicing tasks • Multiprocessing – simultaneous processing of two or more programs by multiple processors • coprocessing • parallel processing, sharing memory – called fault-tolerant systems Ch 5 © The McGraw-Hill Companies, Inc., 2000 15 CCI Memory Management • Virtual memory – hard disk space – when processor needs more RAM space, swaps data onto designated hard drive space – improves flexibility but is slower than RAM which has direct access to the processor Ch 5 © The McGraw-Hill Companies, Inc., 2000 16 CCI Drivers • Handle I/O for specific hardware Ch 5 © The McGraw-Hill Companies, Inc., 2000 17 CCI Utilities Programs • Utilities better than those that are native to an operating system can be purchased Ch 5 © The McGraw-Hill Companies, Inc., 2000 18 CCI System Software Utilities • Types – – – – – Ch 5 backup: system, registry, e-mail, files data recovery virus protection data compression defragmentation © The McGraw-Hill Companies, Inc., 2000 19 CCI Data Compression • Lossy – loss of accuracy, high degree of compression • Lossless – retained accuracy but lower compression ratios Ch 5 © The McGraw-Hill Companies, Inc., 2000 20 CCI Lossy Compression • JPEG – Joint Photographers Experts Group – video storage and editing but not for transmission • MPEG – Motion Pictures Experts Group – storage, editing, and transmission of video Ch 5 © The McGraw-Hill Companies, Inc., 2000 21 CCI Lossless Compression • PC – PKZIP, WINZIP – ARC – PAK .ZIP .ARC .PAK • Mac – StuffIt – PackIt Ch 5 .SIT .PIT © The McGraw-Hill Companies, Inc., 2000 22 CCI Frag and Defrag • Fragmentation refers to the storage of a file in fragments in many areas on a disk • Defragmentation is a utility process that endeavors to bring each file into one whole area within the disk, contiguously Ch 5 © The McGraw-Hill Companies, Inc., 2000 23 CCI Language Translators • These are the compilers and interpreters used to connect programs into machine language to communicate with the processor Ch 5 © The McGraw-Hill Companies, Inc., 2000 24 CCI System Software Interfaces • Command driven • Unix, Linux • Graphical User Interface (GUI) • Microsoft:Windows 9x, Millennium/Neptune, NT, and 2000 • MacOS • GNOME interface to Linux • use of icons, windows (little “w”), high use of keyboard and mouse Ch 5 © The McGraw-Hill Companies, Inc., 2000 25 CCI GUI • Generally, GUI runs on top of operating system to assist users • Some memory is used to provide the GUI Ch 5 © The McGraw-Hill Companies, Inc., 2000 26 CCI OS Platforms • How does Windows 9x/Millennium/ Neptune compare to other operating systems? Ch 5 © The McGraw-Hill Companies, Inc., 2000 27 CCI Common OSs • Mainframe – IBM MVS, VM, DEC VAX/VMS • Midframe – IBM OS-400, Linux, Sun Solaris • Network – Novell NetWare, Lotus Dominoes, Microsoft Windows NT Ch 5 © The McGraw-Hill Companies, Inc., 2000 28 CCI Common Microprocessor OSs • Microcomputer – Microsoft Windows 9x/Millennium/Neptune – Microsoft Windows NT/2000 – Linux – Apple MacOS Ch 5 © The McGraw-Hill Companies, Inc., 2000 29 CCI Windows 9x/Millennium/Neptune • The first customer 32-bit operating system • Windows 98 and 98 SE provide support for printers, video cards, DVD, and USB Ch 5 © The McGraw-Hill Companies, Inc., 2000 30 CCI Windows NT • • • • Network system Scalable to large local area network Multitasking, multiprocessing, multiuser Windows NT Workstation – 1-2 processors • Windows NT Server – up to 32 processors Ch 5 © The McGraw-Hill Companies, Inc., 2000 31 CCI Other Windows OSs • Windows CE provides support for palmtop computers • Windows Millenium, due third quarter 2000, could be the last stand-alone consumer version of Windows 9x, with Windows 2000 in various capabilities coming to the forefront Ch 5 © The McGraw-Hill Companies, Inc., 2000 32 CCI OS/2 Warp • OS/ 2 never established an installed base large enough to attract application developers • Poor marketing, but still supported Ch 5 © The McGraw-Hill Companies, Inc., 2000 33 CCI UNIX • Portable and scalable • Can handle large volumes, such as needed on large Web sites • Strong in medium-to-large businesses Ch 5 © The McGraw-Hill Companies, Inc., 2000 34 CCI Linux • Linux emulates UNIX • Many UNIX programs have been ported to Linux • Open development – can recompile source code • Single user and small to medium Web server support • Since code written for 386, can rehabilitate older systems out of use Ch 5 © The McGraw-Hill Companies, Inc., 2000 35 CCI NetWare • Established network operating system with strong printer and application server functions • Small business edition for up to 25 users priced under NT • Can sustain e-mail traffic through IPX protocol • NT gain in ground, but NetWare a strong base Ch 5 © The McGraw-Hill Companies, Inc., 2000 36 CCI Web • What is a network computer, and how does it involve the Internet and Java? Ch 5 © The McGraw-Hill Companies, Inc., 2000 37 CCI Specialization • Isolation of customer and corporate needs • Software versions by operating systems • Emergence of accessing applications and systems online not just web pages – idea of renting applications only for time used Ch 5 © The McGraw-Hill Companies, Inc., 2000 38 CCI Bloatware • Large percentage of applications have features not used • Network PC – approximates mainframe terminal – sometimes with limited additional capabilities – also called thin client Ch 5 © The McGraw-Hill Companies, Inc., 2000 39 CCI Progress Issue: Bandwidth • Sun’s control of Java Virtual Machine diminishing as computer companies provide optimized VM • Bandwidth increasing substantially through cable, digital subscriber service (DSL) on telephone lines, and the potential of more low-level satellites Ch 5 © The McGraw-Hill Companies, Inc., 2000 40 CCI Java • Developed by James Gosling’s group at Sun • Promise of compile-once, run everywhere not totally realized • Becoming more universal as run times decrease Ch 5 © The McGraw-Hill Companies, Inc., 2000 41 CCI Some Generalities • UNIX and Windows NT on high-end workstations • Mac still used for intensive graphics and desktop publishing • While Linux will not run Microsoft Office, such programs as ApplixWare provides filters to Office 2000 files, so the incompatability is disappearing Ch 5 © The McGraw-Hill Companies, Inc., 2000 42 CCI