SOFTWARE TECHNOLOGIES

Transcription

1 SOFTWARE TECHNOLOGIES (Week 2, Thursday 1/18/2007) BUS300 - Abdou Illia, Spring LEARNING GOALS Identify the different types of systems software. Explain the main functions of operating systems. Describe the various types of applications software and how they are used. Describe the software development process. 2 Example of Computer configuration Intel Pentium 4 Processor 40 (3.20GHz) 12MB SDRAM PC3200 (400MHz), Dual Channel 160GB Serial ATA 7200rpm Hard Disk Drive 16x Multi-Format DVD Writer (DVD±R/±RW) Gateway 7-Bay Tower Case Integrated Ultra ATA Controller (1) PCI-E x16 Expansion Slot, (1) PCI-E x1, (3) PCI in which 2 are available for use (7) USB 2.0 (6 in back and 1 in front in the media card reader), (2) IEEE 1394 Firewire Ports, Parallel, Serial and (2) PS/2 1" Black LCD Flat Panel Display (1" viewable) Gateway Premium 104+ Keyboard Two-Button PS/2 Wheel Mouse (no mouse pad included) Napster 2.0 and 10 Song Sampler Intel High Definition Audio GMAX Speakers with Subwoofer 6K PCI data/fax modem 10/100/1000 (Gigabit) Ethernet Microsoft Office 2003 on CD Processing I/O Output Input 3 1

2 4 Main Types of Software Systems software Systems Software Application Software Programs that manage computer hardware and application software Three types of systems software: Operating systems (e.g. Windows, Linux) Language translators (C++ compiler, VB compiler) Utility programs (Norton Utilities) Main Types of Software Application software Programs that allow users to accomplish specific tasks Examples Word processing Web browser Tax preparation 6 2

3 Operating Systems (OS) Software platform on which other programs run Provides a connection between application programs and the computer hardware Major tasks Starting the computer Managing files Managing Programs and Memory (RAM) Ensuring security Providing a user interface 7 How OS work? System software routines that sits between application programs and hardware to provide: Interface function Key support services Examples of support services: -Communications w/peripheral devices -Launching a program -Copying a file User -Creating a directory -Opening a file Application program Operating system Hardware Interfaces User communicates w/app. Prg. App. Prg communicates w/os OS communicates w/hardware All App. Prg access Hardware through OS according to rules imposed by OS 8 OS: Primary components User interface (shell) Processor (or process) File Memory Device Communication services Shell File Device Provides mechanism for user and App. Prg to communicates w/os and request OS support Allows the user to create, delete, modify, and manipulate files. Controls communications w/peripheral devices Processor Memory Communication services Manages processor s time Manages system s memory Manages comm. Between OS layers and intercomputer communications. 9 3

4 OS at work Line command interface Operating System User interface layer Graphical User interface Voiceactivated interface Other OS layers Open Shell [Open] File Device Hardware Application program Operating system Steps for opening a file 1. User select File/Open from menu 2. App. Prg. calls the [Open] routine in the OS s Shell 3. The [Open] routine passes the Open request to File programs 4. File programs determine where the requested file is located. If file on local computer, request is passed to Device 6. Device communicates with Hardware; i.e. the secondary storage device where the file is. 10 Managing Files OS keeps track of where all files are located Manage disk space usage Free space Used space Creates and manages directory structure 11 Program and Memory Management OS is responsible for Sending programs to the CPU Allocating primary storage (RAM) to programs Controlling devices that programs requires Multiprogramming and Multitasking More than one program in memory at once OS keeps track of memory for each program One program runs until it needs data from the user, then the OS switches to the other program Virtual memory Extending the computer RAM by using secondary storage Used when RAM insufficient to hold programs to be used 12 4

5 13 A technique that extends primary memory (RAM) by using secondary storage devices Needed when there is not enough RAM to hold programs 14 Security Access control Who has access to the computer File permissions Read and/or Modify permissions on files Logging, i.e. auditing the computer Who has accessed the computer What actions they performed 1

6 Providing a User Interface Text or command line interfaces Graphical User Interfaces (GUIs) Voice interface Choosing an OS Must support the applications the business needs to run!! Other considerations Stability How often does OS crash? How does the OS recover from crashes? Security Does the OS provide the required level of security? Ease of use Is the OS easy to learn and to use? 18 6

7 Utility Software Accomplish common tasks and maintenance jobs Defragmentation Virus protection Edit the Windows registry Remove Web cookies from HDD 19 Summary Questions Malaga Notes 1) What are the two main types of software? 2) What are the three types of systems software? 3) What are the functions of the Operating System? 4) (a) Name some Operating Systems. (b) Name some Application software programs. ) What does Multiprogramming mean? 6) What is the major consideration when purchasing an Operating System? 7) What are utility programs used for? 7 6,17 12, Programming Language Generations Programming languages English Machine Language 21 7