7. INFORMATION SYSTEMS SOFTWARE 7.1

LEARNING OBJECTIVES DESCRIBE MAJOR TYPES OF SOFTWARE EXAMINE SYSTEM SOFTWARE & OPERATING SYSTEMS EXPLAIN SOFTWARE EVOLUTION ANALYZE MAJOR APPLICATION LANGUAGES DESCRIBE APPROACHES TO SOFTWARE DEVELOPMENT IDENTIFY SOFTWARE ISSUES * 7.2

SOFTWARE DETAILED INSTRUCTIONS TO CONTROL COMPUTER OPERATION PROGRAM: SET OF INSTRUCTIONS TO THE COMPUTER STORED: PROGRAM MUST BE IN PRIMARY STORAGE SYSTEM SOFTWARE: MANAGES COMPUTER RESOURCES APPLICATION SOFTWARE: SPECIFIC BUSINESS APPLICATION * 7.3

SOFTWARE 7.4 OPERATING SYSTEM: APPLICATION SOFTWARE OPERATING SYSTEM: SCHEDULED COMPUTER EVENTS ALLOCATES COMPUTER RESOURCES MONITORS EVENTS LANGUAGE TRANSLATORS: INTERPRETERS COMPILERS UTILITY PROGRAMS: ROUTINE OPERATIONS MANAGE DATA SYSTEM SOFTWARE HARDWARE PROGRAMMING LANGUAGES: ASSEMBLY LANGUAGE; FORTRAN; COBOL; PL / 1; QBASIC; PASCAL; C; C++; “FOURTH GENERATION” LANGUAGES 7.4

OPERATING SYSTEM MANAGES & CONTROLS ACTIVITIES ALLOCATION & ASSIGNMENT SCHEDULING MONITORING SYSTEM RESIDENCE DEVICE: SECONDARY STORAGE DEVICE STORING OPERATING SYSTEM * 7.5

TRADITIONAL SINGLE-PROGRAM SYSTEM MULTIPROGRAMMING TRADITIONAL SINGLE-PROGRAM SYSTEM OPERATING SYSTEM UNUSED MEMORY PROGRAM 1 PROGRAM 2 PROGRAM 3 MULTIPROGRAMMING ENVIRONMENT OPERATING SYSTEM UNUSED MEMORY PROGRAM 1 7.6

MULTITASKING MULTIPROGRAMMING ON A SINGLE-USER SYSTEM SUCH AS A MICROCOMPUTER * 7.7

VIRTUAL STORAGE METHOD OF HANDLING SEVERAL PROGRAMS IN PRIMARY STORAGE: PROGRAM DIVIDED INTO FIXED LENGTH PORTIONS (PAGES) OR VARIABLE LENGTH (SEGMENTS) CURRENT PORTIONS RESIDE IN PRIMARY STORAGE PORTIONS SWAPPED OUT WHEN DONE * 7.8

TIME SHARING MANY USERS SHARE LARGE CPU: TIME IN CPU DIVIDED INTO SLICES (e.g.: 2 MILLISECONDS) EACH USER HAS ACCESS TO CPU DURING SLICE SINCE CPU IS FAST, CAN DO MUCH DURING TIME SLICE USER’S JOB SWAPPED OUT AT END OF SLICE * 7.9

MULTIPROCESSING TWO OR MORE PARALLEL PROCESSORS IN SYSTEM PROGRAM CAN BE DIVIDED TO BE PROCESSED BY MULTIPLE CPUs CAN PROCESS LARGE PROGRAMS MORE RAPIDLY * 7.10

LANGUAGE TRANSLATION SOURCE CODE: HIGH-LEVEL LANGUAGE INSTRUCTIONS COMPILER: TRANSLATES HIGH-LEVEL CODE INTO MACHINE LANGUAGE OBJECT CODE: TRANSLATED INSTRUCTIONS READY FOR COMPUTER * 7.11

OTHER OBJECT CODE MODULES SOURCE CODE PROGRAM COMPILER OBJECT CODE LINKAGE EDITOR LOAD MODULE TRANSLATION PROCESS OTHER OBJECT CODE MODULES 7.12

GRAPHICAL USER INTERFACE (GUI) OPERATING SYSTEM USES: GRAPHIC ICONS (Icons, Buttons, Bars, Boxes) MOUSE TO ISSUE COMMANDS MAKE SELECTIONS * 7.13

MICROCOMPUTER OPERATING SYSTEMS FEATURES Windows 98 & 95 32-bit operating system; GUI; Multitasking. Networking Windows NT & 2000 32-bit operating system not limited to Intel chips. Multitasking; Multiprocessing; Networking Windows CE Paired-down for handheld computers, wireless communication devices OS/2 32-bit. Developed for IBM PS/2. Multitasking; Networking 7.14

MICROCOMPUTER OPERATING SYSTEMS FEATURES UNIX For powerful Microcomputers, Workstations, Minicomputers. Multitasking; Multi-user Processing; Networking. Portable to various Computer Platforms Mac OS For Macintosh computers. Multitasking. Powerful Graphics; Multimedia For IBM (PC-DOS) and PC (MS-DOS). Program Memory: 640K DOS 7.15

GENERATIONS OF PROGRAMMING LANGUAGES 1st. Since 1940s. MACHINE LANGUAGE: binary code 2nd. Since early ’50s. ASSEMBLY LANGUAGE: mnemonics for numeric code 3rd. Since mid ‘50s. HIGH-LEVEL LANGUAGES 4th. Since late ‘70s. MODERN APPLICATION PACKAGES * 7.16

HIGH-LEVEL LANGUAGES FORTRAN (FORmula TRANslator). Scientific, Engineering applications COBOL (COmmon Business Oriented Language). Predominant for Transaction Processing BASIC (Beginners All-purpose Symbolic Instruction Code). General Purpose PC Language * 7.17

HIGH-LEVEL LANGUAGES PASCAL. Used to Teach Structured Programming Practices. Weak in File Handling, Input / Output C and C++. Powerful PC Language for Developing Applications. Efficient Execution; Cross Platform PL/1 (Programming Language 1). Powerful IBM Language for Business & Science ADA. Designed for Weapon Systems. Can be used on many Platforms. Structured. Can be used for Business * 7.18

ARTIFICIAL INTELLIGENCE LANGUAGES LISP (LISt Processor). Began late ‘50s at MIT. Preferred in US. Require Specially Configured Machines PROLOG. Began in early ‘70s. Preferred outside US. Cross Platform CREATE MEANINGFUL LISTS OF SYMBOLS (Operations; Variables; Data) * 7.19

FOURTH GENERATION LANGUAGES (4GL) CAN BE EMPLOYED BY END USERS NONPROCEDURAL CAN DEVELOP APPLICATIONS QUICKLY NATURAL LANGUAGES SIX CATEGORIES * 7.20

FOURTH GENERATION LANGUAGES (4GL) 1. QUERY LANGUAGES: rapidly retrieve data interactive/ on-line may use NATURAL LANGUAGE support special requests for data from relational databases * 7.21

FOURTH GENERATION LANGUAGES (4GL) 2. REPORT GENERATORS: create customized reports wide range of formats 3. GRAPHICS LANGUAGES: can manipulate drawings, graphs, photos, videos presentation managers * 7.22

FOURTH GENERATION LANGUAGES (4GL) 4. APPLICATION GENERATORS: user specifies computer needs generator creates logic and code for application greatly reduces development time * 7.23

FOURTH GENERATION LANGUAGES (4GL) 5. VERY HIGH-LEVEL PROGRAMMING LANGUAGES: professional programmer productivity tool uses fewer instructions reduces development time * 7.24

FOURTH GENERATION LANGUAGES (4GL) 7. SOFTWARE PACKAGE: commercially available set of programs... WORD PROCESSING SPREADSHEETS DATA MANAGEMENT PRESENTATION MANAGEMENT INTEGRATED SOFTWARE PACKAGES NOW COMBINE THESE TO SIMPLIFY LEARNING AND USE * 7.25

SOFTWARE TOOLS WORD PROCESSING SPREADSHEETS DATA MANAGEMENT PRESENTATION GRAPHICS INTEGRATED SOFTWARE SUITES E-MAIL WEB BROWSERS GROUPWARE * 7.26

GROUPWARE CAPABILITIES GROUP WRITING & COMMENTING ELECTRONIC MAIL DISTRIBUTION SCHEDULING MEETINGS, APPOINTMENTS SHARED FILES & DATABASES SHARED TIMELINES, PLANS ELECTRONIC MEETINGS & CONFERENCES * 7.27

OBJECT-ORIENTED PROGRAMMING COMBINES DATA & PROCEDURES INTO A SINGLE OBJECT PROGRAM SENDS MESSAGE TO OBJECT TO PERFORM EMBEDDED PROCEDURE OBJECT’S DATA ENCAPSULATED FROM REST OF SYSTEM CREATES REUSABLE CODE REDUCES TIME AND COST OF WRITING SOFTWARE * 7.28

OBJECT-ORIENTED PROGRAMMING VISUAL PROGRAMMING: SELECT AND ARRANGE OBJECTS RATHER THAN WRITE CODE CLASS: ALL OBJECTS OF A CLASS HAVE ALL FEATURES OF THAT CLASS INHERITANCE: SPECIFIC CLASS RECEIVES FEATURES OF A MORE GENERAL CLASS OVERRIDE: SUBCLASS MAY OVEERRIDE INHERITED METHOD (e.g.: Printout of an HOURLY worker Pay Check may differ from that of a WEEKLY worker * 7.29

OBJECT-ORIENTED PROGRAMMING JAVA: Sun Microsystems OBJECT-ORIENTED PROGRAMMING LANGUAGE APPLET: TINY PROGRAM TO EXECUTE SMALL FUNCTION APPLETS DOWNLOADED FROM NETWORK RUN ON ANY COMPUTER & OPERATING SYSTEM RESULT SAVED ON NETWORK, NOT ON PC ONLY NETWORK VERSION OF SOFTWARE NEEDS UPGRADE * 7.30

OBJECT-ORIENTED PROGRAMMING ActiveX: CONTROLS FOR WINDOWS SOFTWARE ENVIRONMENT to enable OBJECTS: e.g., CHARTS TABLES ANIMATIONS to be EMBEDDED IN A WEB PAGE * 7.31

Connect to the INTERNET PRESS LEFT MOUSE BUTTON ON ICON TO CONNECT TO THE LAUDON & LAUDON WEB SITE FOR MORE INFORMATION ON THIS CHAPTER 7.32

7. INFORMATION SYSTEMS SOFTWARE 7.33