it fundamentals1 think about your computer applications –surfing the web –creating reports...
TRANSCRIPT
IT Fundamentals 1
Think about your computer
applications– Surfing the web– Creating reports– Analyzing data– Storing information– Making presentation
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Think about behind your computer
Loading and running programsCoordinating networksOrganizing filesProtecting from virusPerforming periodic maintenanceControlling hardware devices
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Think about “what if”s
New application programs can not run on current system
Get a computer virusHard disk failsA new video camera can not store
and edit image on our computerStart and run slower and slower
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SoftwareSoftwareSoftware, also called a program, is a series of
instructions that tells the computer what to do and how to do it.
Two general categories :
1. System Software (Operating System)
a set of programs that interacts directly with hardware (eg: Windows)
2. Application Software:
programs such as Word, Excel and Access these use OS for disk read/writes, display on screen etc.
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Categories of Software
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System Software
Difference between system software and application software
3 basic functions of any operating system
3 categories of operating systemPurpose of utilities and utility suites5 most essential utilitiesDefine device driversLanguage translators
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System Software
Handle the majority of technical details– Where to store in memory– How commands convert– Where a document or file is saved– How the output is printed
Consist of 4 kinds of programs– Operating systems– Utilities– Device drivers– Language translators
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System SoftwareSystem Software1.1 BIOS (basic input/output system) Is stored in the ROM chip
Contains the computer's startup instructions
1.2 Operating System (OS) A series of programs to perform certain functions.
Low level functions loaded on boot-up: read/write disksallocate memory to programsnetwork communicationsinput/output support (eg:device drivers)system security
Higher level functions usually separate programs (utilities): provide initial user interfaceDisk/file managementMonitor system performanceeditorNetwork administration
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Operating systems
Every computer has an operating system3 basic functions of operating system
– Managing resources•Keyboard, mouse, printer, monitor,
storage devices, memory– Providing a user interface
•GUI: graphical user interface– Running applications
•Multitasking: run more than one application at a time
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System SoftwareSystem Software
User interface Manage programs
Manage
security
Schedule jobs and configure devices
Access the webMonitor performanceControl network
Administer
security
Start the computer
Manage memory
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System SoftwareSystem SoftwareStarting up an OS is called BOOTING-UP
Steps in booting up:
•Turn on the computer. Power supply sends electrical signals to all parts of the computer.
•The processor chip looks for the BIOS in the ROM chip.
•BIOS executes POST (power on self test), checks components eg keyboard, drives etc.
•POST results are compared to data in CMOS chip.
•BIOS searches for system files from A: drive , then from C: drive.
•System files are loaded in memory. (RAM)
•Finally, the OS is loaded into memory. (RAM)
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System SoftwareSystem Software
1.3 Categories of OS• users/tasks (a) A single user/single tasking operating system
(b) A single user/multitasking operating system.CPU allows a single user to work on two or more programs that reside in memory at the same time.
Eg. Windows 3.X, windows 95/98
OS allows only one user to run one program at a time eg: DOS
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Categories of OS
• users/tasks
(c) A multi-user operating systemsupports two or more simultaneous users. All mainframes and minicomputers are multi-user systems, but most personal computers and workstations are not. Another term for multi-user is time sharing.Eg. Unix, Linux (multitasking)
(d) A multiprocessing operating system CPU’ssupports two or more Central Processing Units (CPUs) running programs at the same time within a
single computer system Eg. Win NT/2000/XP, Unix, Linux
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Categories of OS
• stand-alone/network/embedded
(a) stand-alone
•works on a desktop computer, notebook computer, or mobile computing device. •Some are called client operating systems because they also work in conjunction with a network operating system. •Client operating systems can operate with or without a network.•Eg. DOS, Windows XP, Mac OS X, OS/2 Warp Client, UNIX, and Linux.
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Categories of OS
(b) Network (NOS) is designed specifically to control a
network and its message (e.g. packet) traffic and queues, controls access by multiple users to network resources.
Eg. NetWare, Windows Server 2003, OS/2 Warp Server for e-business, UNIX, Linux, and Solaris.
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Categories of OS
(c) Embeddedis an operating system for embedded
computer systems.designed to be very compact and
efficient, forsaking many functions that non-embedded computer operating systems provide, and which may not be used by the specialized applications they run.
They are frequently also real-time operating systems.
on most PDAs and small devicesreside on a ROM chip. e.g. Windows CE .NET; Pocket PC 2002,
Palm OS, and Symbian OS.
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Operating SystemsOperating Systems
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Operating SystemsOperating Systems
Windows XP
Mac OS X
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System SoftwareSystem Software
1.4 Features of an OS (a) multi-user
(b) Virtual Memory Management RAM can seemingly be expanded by using some of a hard disk to act as extra 'main memory
(c) Scheduling jobs•OS determines the order in which jobs are done.•Not always first in first done.•Some jobs have higher priority.
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Virtual Memory Maps to Physical Memory
The copying of virtual pages from disk to main memory is known as paging or swapping
To facilitate copying virtual memory into real memory, the operating system divides virtual memory into pages, each of which contains a fixed number of addresses
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System SoftwareSystem Software
1.5 Command Based vs Graphical Unusable if do not know commands eg. copy A:afile.doc C:\bak\newname.doc Graphical presents commands via pull-down menus
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Utility Programs • Type of system software that
allows a user to perform maintenance-type tasks usually related to managing a computer, its devices, or its programs
Programs that make computing easier– Hard disks can crash– Virus can invade a system– Computers can freeze up– Operations can slow down
Five most essential utilities– Troubleshooting programs– Antivirus programs– Uninstall programs– Backup programs– File compression programs
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Windows UtilitiesStart->All programs->accessories->system toolsBackup
– Protect from hard disk failureDisk cleanup
– A trouble-shooting utility– Identifies and eliminates nonessential files– Frees up valuable disk space– Improves system performance
Disk defragmenter– Eliminates unnecessary fragments– Rearranges files and unused disk space
Disk Scanner– detects and corrects both physical and logical
problems– searches for and removes unnecessary files
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Utility Suites
• Combine several programs into one package
(1)Personal Computer Maintenance
(2)Antivirus programs(3)File Compression
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Utility Suites
2 best known utility suites– McAfee Office– Norton System works
•A suite of five separate program groups
•Each can be purchased separately or as part of the suite
– Norton Utilities– Norton AntiVirus– Norton CleanSweep– Norton CrashGuard– Norton Web Services
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Device Drivers
Specialized programs that allow devices to communicate with the rest of the computer system
When computer started, the OS loads all of the device drivers into memory
A new device added, its driver must be installed before it can be used– From windows– From product’s manufacturer
Install drivers in Windows OS– Control panel-Add/Remove Hardware
Wizard
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Programming LanguagesProgramming Languages
•a vocabulary and set of grammatical rules for instructing a computer to perform specific tasks.•Each language has a unique set of keywords and a special syntax for organizing program instructions.
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Programming LanguagesProgramming Languages
1st. Generation
· Machine language· Written in the language of the computer – 0’s and 1’s· The language to which all other generations of languages must be converted. Each different type of CPU has its own unique machine language
Languages improved in parallel with hardware developments.
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Programming LanguagesProgramming Languages
2nd. Generation· Assembly language· Used simple abbreviations or codes to represent a number of machine language instructions· Codes converted to machine language by a special program called an assembler. Eg. SUB STA LDA
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Programming LanguagesProgramming Languages3rd. Generation· High level languages· More English like· Single command generates 100s of machine language instructions· Allow concentration on logic of solving problem rather than controlling computer· Compiler program converts instructions into machine language, stored as an EXEcutable file. Eg. BASIC, COBOL, C
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Programming LanguagesProgramming Languages4th. Generation· Very high-level languages· Non-procedural. Programmer tells computer what to do but not how to do it.· Programmer can be 10 times more productive than in 3rd generation language.· Eg. databse query language (SQL, dBase, Prolog) LIST name FOR town=”Bendigo”
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Programming LanguagesProgramming Languages
5th. Generation
Provides a visual or graphical interface for creating source code.
Use of Natural language
Visual basic is an example
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Which is the best?
• The question of which language is best is one that consumes a lot of time and energy among computer professionals.
• Every language has its strengths and weaknesses. – FORTRAN is a particularly good
language for processing numerical data, but it does not lend itself very well to organizing large programs.
– Pascal is very good for writing well-structured and readable programs, but it is not as flexible as the C programming language.
– C++ embodies powerful object-oriented features, but it is complex and difficult to learn.
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Language Translators
Computers only understand machine language consisting of 0’s and 1’s– Tedious, difficult
Programming language more closely to human language were developed
Language translator– convert programming statements
into zeros and ones– Make computer be able to process
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Application SoftwareApplication Software
2. Application Software • performs some specific application required by the user • current program and data stored in RAM • RAM memory for program allocated by OS • Program stores data within its allocation
2 types ... 1. Specialist eg. Information Systems
ECNU Student Records2. General eg. Word
AccessExcelGamesCADProgramming Language
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Exercise
Finish Tutorial 3: Secondary StorageSave the answer in StuIDNameT3.doc
Prepare for Tutorial 4: Operating System