Session 7 Computer Software

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Session 7 Computer Software

• PART I Introduction to the Foundation of
  Information Technologies

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SOFTWARE
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• PROGRAM Set of instructions to the computer
• STORED Program must be in primary storage
• Software Detailed instructions to control
  computer operation of a computer systems. Without
  software, the computer hardware could not perform
  any tasks.The functions of software are to
• (1) manage the computer resources of the
  organization,
• (2) provide tools for human beings to take
  advantage of the these resources
• (3) act as intermediary between organizations and
  stored information.

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SOFTWARE
HARDWARE
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Operating system

• Allocates and assigns
• memory
• e. g., file system, virtual memory
• processor time
• e. g., multitasking, multiprocessing
• input- output devices
• e. g., printer, keyboard, etc.
• May also provide other capabilities useful to
  many users or programs
• Graphical User Interface (GUI) capabilities
• Fonts, network protocols, ...

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Operating system as magician(???)

• The four illusions
• Many separate computers, one for each process
  Multitasking
• Large memory Virtual memory
• Disks and other secondary storage are organized
  as collections of files File systems
• Windows and menus Graphical User Interface
  (GUI)

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Operating Systems Capabilities Multiprogramming,
Multitasking
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Operating Systems Capabilities Virtual Storage

• Virtual Storage is the 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.

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Operating Systems Capabilities time sharing

• MANY USERS SHARE LARGE CPU
• Time in CPU divided into slices (e.g. 2
  microseconds)
• Each user has access to CPU during slice.
• Single CPU is fast, can do much during time slice
  
• Users job swapped out at end of slice

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Operating Systems Capabilities Multiprocessing

• Links together two or more CPUs to work in
  parallel in a single computer systems to execute
  two or more instructions.
• Program can be divided to be processed by
  multiple CPUs.
• Can process large programs more rapidly

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Operating Systems Capabilities File Systems

• Reality
• Disks are sets of tracks(??)
• Tracks are sets of sectors(??)
• Sectors can store fixed- sized byte blocks
• Illusion
• Disks are sets of directories (??)
• Directories contain other directories or files
• Files are variable- size byte sequences
• Directories and files have names

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Operating Systems Capabilities Windows and Menus

• Reality Screen is an array of pixels(????)
• Illusion 1 Menus
• Depending on where you click, different action
  happens
• Technique OS looks up location where mouse was
  clicked, executes appropriate action
• Illusion 2 Overlapping windows
• A window may cover part or all of another
• When a window is uncovered, its contents are
  redisplayed
• Technique OS saves bitmap(??) of covered
  windows
• Application does not need to know how to redraw
  the contents of its window

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MICROCOMPUTER OPERATING SYSTEMS
OPERATING SYSTEM
FEATURES

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MICROCOMPUTER OPERATING SYSTEMS
OPERATING SYSTEM
FEATURES
Unix
For powerful microcomputers, workstations,
minicomputers. Multitasking, multi-user
processing, networking. Portable to various
computer platforms
Linux
Free, reliable alternative to Unix, Windows. Runs
on many Platforms. Open-source
Mac OS
For Macintosh computers. Multitasking. Powerful
graphics, multimedia
DOS
For IBM (PC-DOS) and PC (MS-DOS). Program
memory 640K
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Selecting an Operating System

• Is our existing software compatible with the
  OS?
• Does the OS have a large base of compatible
  software?
• How reliable is the OS? Does it crash
  frequently?
• Is the OS available for a wide variety of
  hardware?
• How quickly does it run?
• How easy it is to learn and use?
• How easy is it to install and configure?
• How much does it cost?

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SOFTWARE
HARDWARE
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Computer System Operating Process
How to operate in computer ?
71017 ?
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EXAMPLE 710?
Machine Language
Assembly language
Instruction Program 0011 1110 ???(LD A) 0000
0111 ???(7) 1100 0110 ???(ADD A) 0000 1010
???(10) 0111 0110 ???(HALT)
Program LD A, 7 ADD A,10 HALT
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INSTRUCTION EXECUTION CYCLE
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TRANSLATION PROCESS
High-level language instructions
Translates high-level code into machine language
Ready for computer
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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.

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SOFTWARE
HARDWARE
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Utility Programs

• Routine operations
• Eg., Sort, list, print,.
• Manage data
• Eg., create file, merge file, .

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Application Software and Programming Languages

• Programming languages
• evolved from machine language to high-level
  languages for business and scientific work
• Important programming languages for business
  today COBOL, C, C, and Visual Basic, so on

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Programming Languages
C Operating systems application software
C Object-oriented application software
COBOL Business administration alphanumeric processing
Visual Basic Visual tool Windows applications
FORTRAN Processing numeric data scientific, engineering programs
BASIC Used for teaching
Pascal Used primarily for teaching programming
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Fourth-Generation Languages

• Fourth-generation language
• Can help end users develop software with little
  or no assistance from IS specialists, less
  procedural
• 6 CATEGORIES
• Natural languages
• Close to human language

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FOURTH GENERATION LANGUAGES (4GL)
eg.
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CONTEMPORARY TOOLS FOR SOFTWARE DEVELOPMENT

• Object-oriented programming
• Approach to software development that combines
  data and procedures into a single object
• Objects are independent, reusable building blocks
• Based on concepts of class and inheritance
• Visual programming
• Construction of software programs by selecting
  and arranging programming objects

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Class and inheritance
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CONTEMPORARY TOOLS FOR SOFTWARE DEVELOPMENT

• Java
• Object-oriented Programming language,
• Delivers the software functionality needed for a
  particular task
• Runs on any computer and operating system,
  Platform-independent
• Hypertext Markup Language (HTML)
• Page description language, creates Web pages and
  other hypermedia documents
• XML (eXtensible Markup Language)
• Describes the structure of a document, supports
  links to multiple documents, allowing data

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Application Software Packages and Productivity
Software

• PC software tools
• Word processing software Create, format, print
  documents
• Desktop publishing software Produce
  professional-quality documents with greater
  formatting, design capabilities
• Spreadsheets Display data in grid for
  recalculating numerical data
• Data management software Store, manipulate data
  in lists and databases
• Presentation graphics Create professional-quality
  graphics and multimedia presentations
• Integrated Software Packages and Suites Combine
  two or more applications easy data transfer
• Other productivity software
• E-mail software Computer exchange of messages
• Web browsers Access and display Web, Internet
  resources
• Groupware Support activities of workgroups

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Software Package for Enterprise Integration

• Enterprise (business) software
• Eg., ERP, SCM, CRM, .
• Set of integrated modules for major business
  functions
• Allows data to be used by multiple functions and
  business processes
• Legacy system
• System in place for long time

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SELECTED EXAMPLES OF APPLICATION Software Packages

• ENTERPRISE RESOURCE PLANNING MATERIAL
  REQUIREMENT PLANNING MNAUFACTURING RESOURCE
  PLANNING E-COMMERCE, CUSTOMER RELATIONSIP
  MANAGEMENT BUSINESS INTELLIGENCEACCOUNTS
  PAYABLE/RECEIVABLE ARCHITECTURAL DESIGN
  BANKING SUPPLY CHAIN MANAGEMENT
  COMPUTER-AIDED-DESIGN DOCUMENT IMAGING TRAVEL
  AGENCY E-MAIL FINANCIAL CONTROL FORECASTING
  FORMS DESIGN GRAPHICS HOTEL MANAGEMENT HUMAN
  RESOURCES INSTALLMENT LOANS INVENTORY CONTROL
  JOB COSTING/SCHEDULING LIFE INSURANCE HOTEL
  MANAGEMENT SYSTEM MATHEMATICAL / STATISTICAL
  MODELING ORDER ENTRY PAYROLL PROCESS CONTROL
  REAL ESTATE MANAGEMENT SALES DISTRIBUTION
  SAVINGS SYSTEMS STOCK MANAGEMENT TAX
  ACCOUNTING UTILITY CONTROLS WORD PROCESSING

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Software for Enterprise Integration

• Middleware
• Allows two disparate applications to communicate
  to exchange data
• Enterprise application integration (EAI) software
• Ties together multiple applications to support
  enterprise integration

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Enterprise application integration (EAI) software
versus traditional integration
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Software for Enterprise Integration

• Web services
• Universal standards using Internet technology for
  exchanging data between systems
• Web server
• Manages requests for Web pages on computer where
  they are stored
• Application server
• Middleware software handling application
  operations between user and back-end business
  systems

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A multitiered architecture for e-commerce and
e-business
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Software Trends

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• Open Source Development

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Open Source Development

• There is an increasing trend toward using this as
  a method of software development.
• In this method source code is distributed and
  developers can improve and add to code as they
  see fit, good ideas are then included into the
  product.
• This method allows software products to grow and
  improve in a natural organic way.

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Moving your company from products to services

• Supporting the software
• Improving the software
• Integrating the software
• Problems with open source
• anybody, nobody responsible

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Total Cost of Ownership (TCO) of Technology Assets

• Includes both direct and indirect costs
• Hardware and software acquisitions account for
  only 20 of TCO
• TCO for a PC may run to three times original
  purchase price
• Hidden costs can make distributed architecture
  more expensive than centralized mainframes

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Total Cost of Ownership (TCO) Cost Components

• Hardware acquisition
• Software acquisition
• Installation
• Training
• Support
• Maintenance
• Infrastructure
• Downtime
• Space and energy

Managing Hardware and Software Assets
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Rent or Build Decisions Using Technology Service
Providers

• Storage service provider SSP, SAN
• Provides online access to storage devices and
  storage area network technology
• Application service provider ASP
• Delivers applications over networks on
  subscription basis
• Management service provider
• Manages applications, systems, security, storage,
  Web sites, system performance

Managing Hardware and Software Assets
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Model of an Application Service Provider (ASP)
Figure 6-15
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Assignment for Session 7

• Individual Review for session 7
• Reading Materials Textbook chapter 4
• Individual Prepare for session 8
• Reading Materials Textbook chapter 5
• P206-207. Review Quiz
• Write down in your book, not submit
• Group Assignment bring to class
• Please design the software architecture for Mr.
  Wangs Pottery Company, including system
  software, application software.
• Prepare for the CASE QUESTIONS on P.121.
• Prepare for the CASE QUESTIONS on P.139.