Class #2

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Class #2

  1. 1. Intro to Information Systems I System & Application Software ISYS 101 Glenn Booker
  2. 2. System Software <ul><li>System software includes the operating system (OS) and utilities </li></ul><ul><li>The operating system performs the basic functions for a computer to be a computer </li></ul><ul><ul><li>Communicate between software and hardware </li></ul></ul><ul><ul><li>Read from and write to storage </li></ul></ul><ul><ul><li>Manage memory </li></ul></ul><ul><ul><li>Run applications </li></ul></ul>
  3. 3. Operating System <ul><li>The main part of the operating system is the kernel, which is always in memory (“resident”) when the computer’s running </li></ul><ul><li>Other parts of the operating system are called upon as needed (“non-resident”) </li></ul><ul><li>Operating systems are CPU-specific </li></ul><ul><ul><li>You can’t run Windows on a G4 processor </li></ul></ul>
  4. 4. Operating System <ul><li>DOS was a single tasking operating system – you could only run one program at a time </li></ul><ul><li>Most OS’s are multitasking – they can run many programs at once </li></ul><ul><ul><li>One is the foreground application, the others are background applications </li></ul></ul>
  5. 5. Multitasking <ul><li>Older OS’s (Windows 3.1) used cooperative multitasking – the foreground application uses all of the CPU’s attention </li></ul><ul><li>Newer OS’s (MacOS 8-X, Win NT) use preemptive multitasking, which isolates each application in memory </li></ul><ul><ul><li>Even if an application crashes, the operating system doesn’t </li></ul></ul>
  6. 6. Multithreading, Multiprocessing <ul><li>Within one application, multithreading allows several tasks (“threads”) to be done at the same time </li></ul><ul><ul><li>Most modern OS’s use multithreading </li></ul></ul><ul><li>Multiprocessing (MP) is when the computer has more than one CPU </li></ul><ul><ul><li>For symmetric MP, each thread can be assigned to a different CPU </li></ul></ul>
  7. 7. Memory Management <ul><li>Memory (RAM) is divided into partitions for each application </li></ul><ul><li>If RAM is limited, part of the hard drive can become virtual memory </li></ul><ul><li>Chunks of memory are divided into “pages” to pass in and out of virtual memory </li></ul><ul><li>Pages are written in a swap file on hard disk </li></ul>
  8. 8. Interfaces <ul><li>Hardware interfaces are controlled by programs called device drivers </li></ul><ul><ul><li>Most are installed automatically </li></ul></ul><ul><li>User interfaces are </li></ul><ul><ul><li>Command line (DOS, UNIX) </li></ul></ul><ul><ul><li>Menu-driven (CMOS – see later) </li></ul></ul><ul><ul><li>Graphical user interface (MacOS, Windows) </li></ul></ul>
  9. 9. User Interface <ul><li>The user interface lets the user </li></ul><ul><ul><li>Gain access to the computer (log in) </li></ul></ul><ul><ul><li>Run applications </li></ul></ul><ul><ul><li>Manage disks and files </li></ul></ul><ul><ul><li>Shut down the computer safely (necessary since DOS) </li></ul></ul>
  10. 10. Types of Operating Systems <ul><li>UNIX is a 30+ year old family of operating systems </li></ul><ul><li>Mostly used for servers and workstations </li></ul><ul><li>Dependable and very powerful, but hard to learn and somewhat obtuse (rename = mv) </li></ul><ul><li>Two major subfamilies: IBM System V and Berkeley BSD </li></ul>
  11. 11. Major UNIX Brands On Intel-based computers, SCO and BSD are also available. Tru64 UNIX DEC/ Compaq HP/UX HP Irix SGI MacOS X Apple Solaris, SunOS Sun AIX IBM
  12. 12. Types of Operating Systems <ul><li>MS-DOS powered the IBM PC in 1981, and is still partially the basis for Windows ME </li></ul><ul><ul><li>Command line interface </li></ul></ul><ul><ul><li>Copied by PC-DOS, DR-DOS </li></ul></ul><ul><ul><li>640 kB RAM limit originally </li></ul></ul><ul><li>While Xerox invented the GUI in the late 70’s, Apple capitalized on it with the Macintosh, now running MacOS 9 or X </li></ul><ul><ul><li>32-bit System 7 released in 1991 </li></ul></ul>
  13. 13. Types of Operating Systems <ul><li>Microsoft Windows </li></ul><ul><ul><li>Windows 3.x added GUI on top of DOS, but treated CPU as though it were 16-bit </li></ul></ul><ul><ul><li>Windows 95, 98, and ME are all still DOS-based, but try hard to be 32-bit operating systems </li></ul></ul><ul><ul><li>Windows NT and 2000 are clean 32-bit OS’s, which emulate DOS if needed </li></ul></ul>
  14. 14. Types of Operating Systems <ul><li>Windows CE (WinCE?) is used for small portable devices (palmtops) (Windows lite) </li></ul><ul><li>Linux is a clone of UNIX, developed starting in 1991 by Linus Torvalds </li></ul><ul><ul><li>A third of Web servers run Linux </li></ul></ul><ul><ul><li>New GUI’s (Gnome and KDE) help reach desktop market </li></ul></ul>
  15. 15. Types of Operating Systems <ul><li>Mainframe or minicomputer operating systems include Unix and: </li></ul><ul><ul><li>IBM’s OS/390 for S/390 computers </li></ul></ul><ul><ul><li>IBM’s OS/400 for AS/400’s </li></ul></ul><ul><ul><li>Compaq’s VMS for VAX/VMS or OpenVMS-based computers </li></ul></ul>
  16. 16. Types of Operating Systems <ul><li>Windows XP (“Whistler”) will be first Windows operating system for home and office which is 32-bit clean </li></ul><ul><ul><li>It’s about time! </li></ul></ul><ul><ul><li>A special 64-bit version will be made for Itanium </li></ul></ul><ul><li>BeOS (www.be.com) is a free OS for graphic and multimedia applications </li></ul>
  17. 17. Computer Startup <ul><li>Starting a computer is “booting” it </li></ul><ul><ul><li>From turned off, it’s a “cold boot” </li></ul></ul><ul><ul><li>From already running, it’s a “warm boot” </li></ul></ul><ul><li>First see the BIOS (Basic Input/Output System) screen </li></ul><ul><ul><li>BIOS controls what the computer boots from (floppy, hard drive, CD) and helps initially configure the hard drives </li></ul></ul>
  18. 18. Computer Startup <ul><li>After the BIOS is happy, the Power On Self Test (POST) makes sure the hardware is attached </li></ul><ul><ul><li>Checks RAM, hard drive, floppy, keyboard, and mouse </li></ul></ul><ul><li>Then the OS loads into RAM </li></ul><ul><li>Then you can log in </li></ul>
  19. 19. Profiles <ul><li>If your OS supports multiple logins, then when you log in you get: </li></ul><ul><ul><li>Unique desktop appearance as defined in your user profile </li></ul></ul><ul><ul><li>A home directory for your files </li></ul></ul><ul><ul><li>Varying privileges for running applications </li></ul></ul>
  20. 20. Utilities: File Management <ul><li>Basic file management utilities (like Windows Explorer) help organize files </li></ul><ul><li>Files under Windows have a file name (myfile), a period, and extension (doc) </li></ul><ul><ul><li>The extension is used to associate files with the application used to open them </li></ul></ul><ul><li>Files are kept in directories (folders) </li></ul>
  21. 21. Utilities: Backup <ul><li>Backup utilities help archive the contents of your hard drive(s) in case of disaster or severe corruption of the disk </li></ul><ul><li>Full backup copies everything in the disk (or specified folders) </li></ul><ul><li>Incremental backup copies only those files which changed since the last backup </li></ul>
  22. 22. Utilities: File Compression <ul><li>File compression utilities squash files and directories to make backup or transfer (e.g. via floppy or email) easier </li></ul><ul><li>WinZip and StuffIt are the most common </li></ul><ul><li>Pkzip was an early DOS/Windows version </li></ul><ul><li>Text files and bitmaps compress the best; some formats are already compressed (JPG) </li></ul>
  23. 23. Utilities: Disk Scanning & Defragmenting <ul><li>Some utilities help manage the physical hard drives, including defragmenting </li></ul><ul><li>They also scan, erase, and format drives </li></ul><ul><ul><li>Windows has built-in “scandisk” & defrag tools </li></ul></ul><ul><ul><li>DiskKeeper is used for Windows NT or 2000 </li></ul></ul><ul><ul><li>FWB Hard Disk Toolkit for Mac </li></ul></ul>
  24. 24. Application Software <ul><li>Application software is broken into horizontal and vertical apps </li></ul><ul><ul><li>Horizontal apps are widely used across many types of work (Word, Excel, etc.) </li></ul></ul><ul><ul><li>Vertical apps are designed to manage one entire business function (e.g. manufacturing) </li></ul></ul><ul><li>Custom software is needed if one of the above doesn’t meet your needs ($$$$) </li></ul>
  25. 25. Application Software Types <ul><li>Three major categories of horizontal apps used for business </li></ul><ul><ul><li>Personal productivity (Office) </li></ul></ul><ul><ul><li>Multimedia & graphics (Photoshop, Fireworks, Paint Shop Pro, PageMaker, Quark) </li></ul></ul><ul><ul><li>Internet (Outlook, FrontPage, Internet Explorer, Netscape) </li></ul></ul><ul><ul><li>Plus personal finance & tax software for home </li></ul></ul>
  26. 26. Software Requirements <ul><li>The required hardware and software for running an application typically includes </li></ul><ul><ul><li>Type of CPU </li></ul></ul><ul><ul><li>Type of operating system </li></ul></ul><ul><ul><li>Amount of RAM </li></ul></ul><ul><ul><li>Amount of hard drive space free </li></ul></ul><ul><ul><li>Other special needs (mouse, CD-ROM, etc.) </li></ul></ul>
  27. 27. Software Licensing <ul><li>Commercial software is often charged per copy of the software, or per CPU </li></ul><ul><li>Shareware is free, but you should send in money if you use it a lot </li></ul><ul><li>Freeware is free </li></ul><ul><li>Some software is public domain </li></ul>
  28. 28. Software Licensing <ul><li>Linux falls under the GNU Public License (GPL) </li></ul><ul><li>Some demos or beta versions are time or feature-limited </li></ul><ul><li>Academic software might have time or feature limits </li></ul><ul><li>Site licenses help manage large facilities </li></ul>
  29. 29. Software Distribution <ul><li>Software may be distributed on CD-ROM or downloaded via the Internet </li></ul><ul><li>Documentation may be electronic (PDF) and/or paper </li></ul><ul><li>Versions (3.0) indicate a major revision; </li></ul><ul><li>Maintenance releases (3.1) indicate minor improvements and fixes </li></ul>
  30. 30. Software Installation <ul><li>Software is installed using a special program for that purpose </li></ul><ul><li>Installers uncompress files, and copy them to your hard drive </li></ul><ul><li>Windows apps add entries in the Registry, and in the Control Panel called Add/Remove Programs </li></ul>
  31. 31. Software Installation <ul><li>Registration of the software is expected immediately after installation </li></ul><ul><li>Some apps come with uninstall programs, too – otherwise use Add/Remove Programs to delete them (please!) </li></ul>
  32. 32. Visual Metaphors <ul><li>Good software is based on familiar visual appearances </li></ul><ul><ul><li>Word processing looks like a letter </li></ul></ul><ul><ul><li>Spreadsheet looks like that used by an accountant </li></ul></ul><ul><ul><li>Databases look like file cards </li></ul></ul><ul><ul><li>Contact managers look like an address book </li></ul></ul><ul><ul><li>Personal finance program looks like checkbook </li></ul></ul>
  33. 33. Integrated Applications <ul><li>Often applications from a single vendor are integrated to work more closely with each other </li></ul><ul><ul><li>MS Office, Works </li></ul></ul><ul><ul><li>Lotus SmartSuite, Corel Office </li></ul></ul><ul><li>On a larger scale, this leads to vertical applications (e.g. SAP) </li></ul>
  34. 34. Windows Environment <ul><li>A typical window has: </li></ul><ul><li>Title bar at the top, with minimize, maximize, and close window controls on the right of the title bar </li></ul><ul><li>Then a Menu bar (File, Edit, …) </li></ul><ul><li>Then one or more Toolbars </li></ul><ul><li>Your work is in the Application workspace </li></ul>
  35. 35. Windows Environment <ul><li>The right side of the window has the scroll bars, arrows, and boxes </li></ul><ul><li>Under the workspace is the status bar (which tells you when you’re printing, etc.) </li></ul>
  36. 36. Word Processing <ul><li>Word processing allows composition of letters, reports, and other major documents with few formatting needs </li></ul><ul><ul><li>If you need complex formatting, use a desktop publishing program instead </li></ul></ul><ul><li>Basic word processing allows for creating, editing, formatting, and printing a document </li></ul>
  37. 37. Word Processing <ul><li>One document might be broken into Sections </li></ul><ul><ul><li>Each section can have its own margins, orientation (landscape vs portrait), page numbering, headers and footers </li></ul></ul><ul><li>Within a section, the paragraph is the next major element </li></ul>
  38. 38. Word Processing <ul><ul><li>Each paragraph may have styles associated with it, as well as line spacing, indenting, and spacing before and after the paragraph </li></ul></ul><ul><li>Below the paragraph, the character is the next unit </li></ul><ul><ul><li>Each character may have a font size, style, color, and other effects (shimmer, etc.) </li></ul></ul><ul><ul><li>Symbols and images are characters </li></ul></ul>
  39. 39. Word Processing <ul><li>Word processing programs can add other features, like: </li></ul><ul><ul><li>Footnotes and endnotes, page numbers, tables of contents, indexes, etc. </li></ul></ul><ul><ul><li>Tracking changes for document review </li></ul></ul><ul><li>Beware of grammar and spelling checkers! </li></ul><ul><ul><li>Many errors won’t be caught be them </li></ul></ul>
  40. 40. Spreadsheets <ul><li>Spreadsheets mimic an account’s spreadsheet – used to add rows and columns of numbers </li></ul><ul><li>Now they also do charts and help analyze data </li></ul><ul><li>Data are in columns (for each type of data) and rows (for each record or transaction) </li></ul>
  41. 41. Spreadsheets <ul><li>Excel limited to 256 columns and 65,536 (64k) rows </li></ul><ul><li>One spreadsheet document can have many “sheets” (up to available memory) </li></ul><ul><li>Spreadsheets calculate based on cell name references = A1 + B3*C3 </li></ul>
  42. 42. Spreadsheets <ul><li>Spreadsheets recognize three types of data </li></ul><ul><ul><li>Numbers (including percent, integers, real numbers) </li></ul></ul><ul><ul><li>Dates and/or times </li></ul></ul><ul><ul><li>Text (“Hi this is a text cell”) </li></ul></ul><ul><li>Fill handles or autofill help enter patterns of data quickly </li></ul>
  43. 43. Spreadsheets <ul><li>Fixed, or absolute cell references can be defined = $A$1 + B3*C3 (fixes A1) </li></ul><ul><li>Math functions can be used (beware of weak statistical functions) = SUM(B1:G1) </li></ul><ul><li>Formatting of fonts, rows, columns, page breaks, etc. can be done too </li></ul>
  44. 44. Spreadsheets <ul><li>Most charts can be generated using the Chart Wizard </li></ul><ul><ul><li>Also can embed Excel objects, including data and charts, in a Word document </li></ul></ul><ul><li>Macros can be used for more complex programming in Excel </li></ul><ul><li>Be sure to check sample calculations! </li></ul>
  45. 45. Presentations <ul><li>Presentation graphics (PowerPoint) are generally for less technical work than analytical graphics (Excel or SPSS) </li></ul><ul><li>Images are based on vu-graph slides </li></ul><ul><li>Slides can be viewed together (slide sorter), or view an outline of the presentation </li></ul><ul><li>The Notes view reminds you what to say </li></ul>
  46. 46. Presentations <ul><li>A master slide can contain common elements you want in the background for every slide (logos, copyright data, presentation or presenter name, etc.) </li></ul><ul><li>Now presentations can have headers and footers too, like Word documents </li></ul>This stuff is in the footer!
  47. 47. Presentations <ul><li>Templates can provide a set of predefined layouts and fonts, but generally do so at the expense of contrast (use a good projector!) </li></ul><ul><li>Entire presentations are outlined in the AutoContent Wizard (under File / New) </li></ul><ul><li>Animation and movement can also be used </li></ul><ul><li>But sometimes </li></ul>badly
  48. 48. Presentations <ul><li>Sound, video, and Internet content are possible </li></ul><ul><li>Keep the content focused on each slide </li></ul><ul><li>Some recommend no more than five lines, with 5 words per line (the 5x5 rule) </li></ul><ul><li>Fonts generally shouldn’t go below 24 point </li></ul><ul><li>This is 32 point Times, with 44 point titles </li></ul>
  49. 49. Databases <ul><li>Databases are used for storing, sorting, and analyzing lots of data </li></ul><ul><li>Data is stored in tables </li></ul><ul><li>Forms are used for displaying and entering data </li></ul><ul><li>Reports are used for output of data </li></ul><ul><li>Queries are used to select data from tables </li></ul>
  50. 50. Database Tables <ul><li>Tables have records; records are like rows in Excel </li></ul><ul><li>Each record (customer) has one or more fields in it (name, address, zip code); fields are like columns in Excel </li></ul><ul><li>Each field has a data type (text, number (integer or real), money, date, T/F, etc.) </li></ul>
  51. 51. Databases <ul><li>Each table is one type of information which can be associated with one unique identifier </li></ul><ul><ul><li>A person has a SSN </li></ul></ul><ul><ul><li>A purchase order has a PO number </li></ul></ul><ul><li>That unique identifier is the “primary key” </li></ul><ul><li>One event (a purchase) may involve data from several different tables </li></ul>
  52. 52. Databases <ul><li>For example, one customer may have placed many orders </li></ul><ul><li>A single order may have many items in it </li></ul><ul><li>But a customer might have only one shipping address </li></ul><ul><li>Those one-to-many and one-to-one relationships make a relational database </li></ul>
  53. 53. Databases <ul><li>The use of relational data prevents duplication of data, and allows analysis in many ways otherwise not possible </li></ul><ul><li>Reports can be generated which draw from many tables </li></ul><ul><li>Forms may accept input which goes into several tables </li></ul>
  54. 54. Databases <ul><li>Queries draw from many tables to find, for example, a particular type of data, e.g. </li></ul><ul><ul><li>Find all of the customers in the Delaware valley </li></ul></ul><ul><ul><li>Determine the total sales for each sales person last month </li></ul></ul><ul><ul><li>Which suppliers have been most reliable? </li></ul></ul><ul><ul><li>When do we need to reorder tuna fish? </li></ul></ul>
  55. 55. Other Database Considerations <ul><li>Validation: databases can check their inputs and outputs to make sure they are the correct format and range </li></ul><ul><li>Data integrity refers to data being a correct possible value (gender = M or F, not Q) </li></ul><ul><li>Database independence refers to the ability to keep the data when the database program needs to be updated or replaced </li></ul>
  56. 56. Other Database Considerations <ul><li>Data should be kept in only one place (no redundancy) </li></ul><ul><li>Data needs to be secure, so that only those who need to get to it may do so </li></ul><ul><li>Maintenance issues need to be addressed, such as adding or deleting data or users of the database </li></ul>
  57. 57. Other Database Considerations <ul><li>Large scale databases need to consider the need for replication , where several copies of data are maintained in different servers </li></ul><ul><ul><li>Local replication is also done (e.g. sales staff maintaining a replica of product features and costs) </li></ul></ul><ul><li>The location where computation is done may be distributed to different servers </li></ul>
  58. 58. Other Database Types <ul><li>A flat file database is like using multiple spreadsheets (FileMaker Pro, or COBOL) </li></ul><ul><li>Object-oriented databases exist; some are cross-bred with relational databases to make object-relational databases </li></ul><ul><li>Groups of databases can form warehouses or data marts, and support data mining </li></ul>
  59. 59. Database Architecture <ul><li>Databases can be client/server architecture (users run a client program, which asks the server for data as needed) </li></ul><ul><li>Or many databases are becoming web-based (typically using CGI, ASP (Microsoft), or JSP (Sun) programs to query the database) </li></ul>

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