describe the ring topology?discuss the Advantage and disadvantage .

describe the ring topology?discuss the Advantage and disadvantage .

Ring Topology                           In a ring topology, each computer is connected to the next computer and the last computer is connect... 21:03

Ring Topology
                          In a ring topology, each computer is connected to the next computer and the last computer is connected to the first. thus, shape of network is formed just like a ring. Data on the network flows in one direction around the ring until it reaches to destination.

Working of Ring Topology
                   In ring topology, a token is passed around the network. the computer that has control of the token can transmit data/message. When  computer sends a message to another computer on the network, the message flows one computer to the next computer. Every computer receives message from  previous computer and re-transmits it to the next computer until the destination computer receives the message. the

destination computer sends an acknowledgement of receiving  message to the sender computer. the sender computer then releases the token back to the network. this method of controlling access to the shared network cable is called Token Passing.

Advantages
the main advantages of ring topology are as follows:
1-    it is less expensive then star topology.
2-     it is easy to install and to maintain.
3-    All computers have equal access to the network.
4-    Every computer regenerates/refreshes the data single that's why it can travel over longer distance.

Disadvantages
the main disadvantages of ring topology are as follows:
1-   if one node fails (or ring is broken at any point), the entire network stops functioning.
2-   Adding or removing a computer in the network affects the whole network.  

what is computer networks?what are server computer and terminals or nodes used in computer network?

what is computer networks?what are server computer and terminals or nodes used in computer network?

Computer network A collection of computers and other devices that are linked together by communication channels or lines for sharing informa... 22:28

Computer network
A collection of computers and other devices that are linked together by communication channels or lines for sharing information and other resources is called computer networks. The resources may include printers, scanners, and hard disks etc. computer networks is also called the information network are simply net. The most popular information network is the internet.

   Ina computer network, two important technologies:computing and telecommunication work together.The computers on a network may be linked through cables,telephone lines, radio waves (wireless), and satellites etc. Figure 2.1 shows the computer network.

      In a computer network, network operating system is used that cables the connected computes to communicate with each other. the example of these operating system are: Windows NT, UNIX, and Novell etc.

Server Computer & Terminals

      A computer and the network that controls the overall functioning of a network is called server computer. it is also known as central computer. in addition to control the network, all data files and software are stored on server computer. A powerful computer is installed as server computer in the network.

                  The devices other than server computer within the network are called terminals. Terminals are also known as nodes. A node may be personal computer, printer,scanner, monitor etc. The users in the computer network access data and other resources through terminal computers.

what is a secondary storage device?list different type of secondary storage devices used in computers.

what is a secondary storage device?list different type of secondary storage devices used in computers.

Secondary Storage Device the main memory or RAM of the computer is volatile. It cannot be used permanent storage because when computer is sw... 21:31

Secondary Storage Device
the main memory or RAM of the computer is volatile. It cannot be used permanent storage because when computer is switched off, its contents are erased. storage capacity is also very small.

A secondary storage device is a computer hardware component. it is used to storage data and programs permanently for later use. secondary storage devices are also called auxiliary storage devices or backing storage devices. Examples of secondary storage devices are floppy disk, USB driver, hard disk, CD/DVD ROMs etc.

A secondary storage device performs two functions. these are writing and reading data to and from the storage media.
1-  Writing data means recording data form memory  to a storage medium.
2-   Reading or retrieving data means transferring data form storage medium in to computer's memory       for use by the operating system or application program.

Types Of Secondary Storage Devices
Following are important types of secondary storage devices:
1- Magnetic tape
2- Magnetic disk

Magnetic tape
Magnetic tape is the most popular and oldest storage medium.it is used to store large amount of data and instructions permanently. the magnetic tape is a plastic ribbon with width of 0.50 inch to 1 inch. one side of tape is coated with magnetic recording material. the storage capacity of tape is up to 100GB and offers an inexpensive way to store a lot of data on a single cassette.
Magnetic Disk
Magnetic disk is a device that write/reads data to and form a magnetic tape. it has two heads. these are write head and read head. the write head encodes the magnetic signals on the tape as it moves across the write head. similarly, the read head reads the stored data from tape and transfers it into the RAM.

write short notes on the following memory devices?

write short notes on the following memory devices?

Random Access Memory (RAM) A type of memory on with CPU can perform read and write operations randomly is called Random Access Memory (RAM).... 04:31

Random Access Memory (RAM)
A type of memory on with CPU can perform read and write operations randomly is called Random Access Memory (RAM). it is read and write memory.it is because CPU can perform both read and write operations on RAM. in this memory, access time is the same for any memory location (address). it is very fast memory. most semiconductor memories and magnetic disk memories are random access memories.
RAM is divided into two types:
1-  DRAM(Dymatic Random Access Memory): This type of RAM is used in most of the computer. in order to maintain data in DRAM, it is refreshed with electric charge again; otherwise data stored into it can be lost.
2-  SRAM(Static Random Access Memory) it does not have to be refreshed with electric charge again  and again.
Sequential Access Memory
this type of memory on with CPU performs read and write operations sequentially is called sequential Access Memory. it is very slow memory. the information is read and stored in sequential order i.e. one after the other. the access time is different for different locations (addresses). Magnetic tape is an example of sequential access memory.
Dynamic Memory Device
the memory devices that must be refreshed with electric charge periodically (again and again) are called dynamics memory devices. these are semiconductor memory devices. if a dynamic memory device is not refreshed with electric charge, information stored into it can be lost.
Static Memory Device
the memory device that do not need to be refreshed with electric charge periodically are called static memory devices. these are semiconductor memory devices.the static memory devices are faster than dynamic memory devices. SRAM is an example of static memory device.
Read-Only Memory (ROM)
in the type of memory, instruction and information are permanently stored. the instructions and information are stored in ROM by the manufacturer at the time of its manufacturing. Once instructions and information re stored in ROM they cannot be changed or removed.

rbriefly explain the computer memory.How read and write operations are performed on memory?

rbriefly explain the computer memory.How read and write operations are performed on memory?

Memory A components of computer that stores data and programs is called its memory. digital computer has two types of memories: internal/ pr... 00:53

Memory
A components of computer that stores data and programs is called its memory. digital computer has two types of memories: internal/ primary memory and secondary memory.

internal memory is a temporary memory or primary memory. RAM is an example of internal memory. in this type of memory, following items are stored when computer working:-
1-   Operating system and other system software that control or maintain the computer and its devices. for example, Windows and device drivers.
2-     Application programs that are used to perform specific tasks.For example, word processing program, spreadsheet program etc.

3-     Data that is to be processed by application programs and results of the programs.
the role memory to store both data and programs is known as the stored program concepts.

the secondary memory or storage of computer is used to stored larged amount of data and programs permanently. it is also known as mass storage. Hard disk, CD-ROM's, and USB flash drive are examples of secondary storage's.

the read are write operation on memory is performed as follows:
1-  A particular address of memory is selected to perform read or write operation.
2-   Read or write operation is selected.
3-   In write operation, input data is supplied to be stored in memory. Similarly, in read operation, output data coming from memory is received.
4-  Enable (or disable) the memory so that it will (or will not) respond to the address inputs and read/write command.

describe the types of printers depending upon printing mechanism.OR what are the impact and non-impact printers?

describe the types of printers depending upon printing mechanism.OR what are the impact and non-impact printers?

impact and non-impact printers Different printers have different printing mechanisms. Therefore, printers are classified into two  main cate... 06:12

impact and non-impact printers
Different printers have different printing mechanisms. Therefore, printers are classified into two  main categories / types depending upon their printing mechanism.

1-     Impact printers                                 2-   Non-impact printers


1-   Impact printers
The printers that produce output on paper with striking the paper are known as impact printers. Impact printers work like typewriter. They use the eletro-mechanical mechanism to print the output on paper. They print characters and graphics on the paper by striking the print hammer or wheel against an inked ribbon.

impact printers are slower in printing and produce low quality output. They also produce more noise during printing. the examples of impact printers are character printers (such as dot matrix printer and wheel printer) and line printer (such as chain printer and drum printer).
2-     Non-impact printer
The printers that produce output on paper without striking the paper are known as Non-impact printers. They use electronic, inkjet, and thermal technologies for printing .

Non-impact printers are faster and produce high quality output then impact printers. They can print up to 24 pages per minute. They produce no noise during printing. these printers are costly than impact printers. the examples of Non-impact printers are laser printer, inkjet and thermal printers.

what are printers?briefly describe their categories/ types.

what are printers?briefly describe their categories/ types.

Printers Printers are the most commonly used output devices. they are used to produce the hard-copy of the output. the output printed on the... 00:36

Printers
Printers are the most commonly used output devices. they are used to produce the hard-copy of the output. the output printed on the paper is called hardcopy . the output may be in the form of characters, symbols and graphics(i.e.drawing or charts).
A printer is connected to a parallel port of system unit by a cable. the parallel port is also called LPT1 (LPT1 is short for line printer 1).
Different types of printers are available. the main difference between printers depends upon printing quality and printing speed.
Types of printer
the main types of printers are follows:
1-    Character printer                                      2-    Line printer
3-     Page printer
1-    Character printer:
The printers that make hardcopy by printing one character at a time are called character printers. A typewriter is an example of character printer. A character printer can print about 30 to 300 characters per scond (cps).
the advantage of character printer is that it is less expensive. However, there are many disadvantages of character printers. the main disadvantages are :
 they are slower in printing.
they produce low quality output.
they produce more noise during printing.
in the past, character printers were very popular. they were commonly used with personal computers to print the information on paper. Today they are rarely used. they examples of character printers are dot matrix printer and daisy wheel printer.
2-  Line Printers
The types of printers that print a complete line of characters at a time are called line printers. they are faster than character printers. the printing speed of line printer is measured in line per minute (lpm). it is about 200 lines per minutes. line printer are normally used with mainframe and mini computers. the examples of line printers are ; chain printers and drum printers.
3-  Page printer
The types of printers that print a complete page of output at a time are called page printers. Normally, printing speed of a page printer is about 4 to 32 pages per minute. laser printer is an example of pages printer.

what is flat panel monitors? describe different types of technologies used in flat panel monitors.

what is flat panel monitors? describe different types of technologies used in flat panel monitors.

Flat-panel monitor Falt-panel monitor is a lightweight, thin screen. it consumes less power then CRT monitor.it can operate with a charged b... 07:43

Flat-panel monitor
Falt-panel monitor is a lightweight, thin screen. it consumes less power then CRT monitor.it can operate with a charged battery. However, it is more expensive than CRT monitor.

Flat-panel Displays are made up of two plates of glass. these plates contain substance in between them. this substance is activated in different ways.

Flat panel monitor are available with different sizes such as 15, 17, 18, 20, 21 and 23 inches. the standard size of panel monitors for laptop computers is 15 or 16 inches. Flat panel monitors are commonly used in mobile devices such as laptops, tablet PCs, PAD and mobile phones. Today, Flat panel monitors are also used with personal computers.

some important types of technologies used in Falt-panel monitors are as follows:
ELD
ELD stands for Electroluminescent Display.it was the first flat screen that was used in portable computers. ELD technology works by placing a thin phosphorescent film between two plates. Each of the plates used are coated with a vertical or horizontal wire grid that align with each other where each crossing point forms a pixel.

Liquid-Crystal Display (LCD)

LCD uses liquid crystal between the glass plates. the output image is formed by liquid crystal. when an electric current passes through liquid crystal, its molecules twist.

what is CRT monitor?describe the refresh rate or refresh CRT and persistence.

what is CRT monitor?describe the refresh rate or refresh CRT and persistence.

CRT Monitor CRT stands for cathode-Ray tube. A type of monitor that uses CRT to display output on the screen is known as CRT monitor. CRT is... 22:51

CRT Monitor


CRT stands for cathode-Ray tube. A type of monitor that uses CRT to display output on the screen is known as CRT monitor. CRT is also used in TV set. a cathode ray tube is a vacuum tube. it creates the image of the output and displays on the screen the front of the tube is the screen. the back of the screen is coated with phosphor (chemical material that lights up when electron beam falls on it). the screen is organized into a grid of tiny dots of phosphor material. these dost are called pixels (picture elements).

CRT consists of one or more electronic guns. A stream of bits defining the image of output is sent from the computer ( from the CPU) to the CRT, where the bits are converted into beam of electrons passes through focusing and deflection systems. they direct the beam towards specified points on the phosphor-coated screen. when beam of electrons hits the screen, it lights up the selected pixels and an image of output is generated on the screen. Today, most of the PCs have color monitors. CRT in color monitor contains three electron guns; on for red color , second for green and third for blue color (RGB). other colors for output are generated with the combination of three colors. computer controls the three guns. color monitors consume relatively more power.

Refresh Rate or Refresh CRT
the refresh rate is the number of times per second the electron guns scan every pixel on the screen to redraw the images on the screen. it is measured in Hertz (Hz) or in cycles per second. refresh rate is also called refresh CRT.

Persistence
the screen of the CRT monitors may be coated with different types of phosphors. the light emitted by some type of phosphor fades rapidly, while other type fades slowly. the duration of emitting light by dots of phosphor after the electron beam is removed is called persistence (the word"persist" means "continue to be").

what is monitor?Also describe the characteristics of monitor.

what is monitor?Also describe the characteristics of monitor.

MONITOR Monitor is also called display screen. it is a commonly used output device. it is used as soft-copy output device. the output may be... 03:52

MONITOR
Monitor is also called display screen. it is a commonly used output device. it is used as soft-copy output device. the output may be in the form of text, graphics and video.
Type of Monitors
Monitors are divided into two types:CRT Monitor and flat-panel Monitor.
Characteristic of Display Screen
Monitors are catheterized according to the following parameters:
1.   Size
2.   Color
3.   Resolution
Size
Monitors are available in various sizes. The common sizes are 15,17,19,21, and 22 inches. The large size monitors are more expensive. The size  of monitor is measured diagonally from one corner to other of the screen.
Color


Today,most of the monitors show output in multiple colors. The commonly used monitor is the RGB screen. RGB stands for Red, green and Blue. RGB monitor can create 256 different colors and thousands of variations of these colors.
Some monitors show output is single color. These monitors are known as monochrome monitors.Today,these monitors are rarely used.
Resolution
The monitor's screen is divided into small dost. These dots are called pixels for picture elements. the pixels are arranged horizontally and vertically. the number of pixels on a screen is called its resolution. the monitor's screen that has large number of pixels has high resolution. High resolution monitors have (2000)(200) pixels. the resolution refers to the sharpness and clearness of an image or picture.

write short notes on "digital camera and video camera".what is audio input and audio input device?write short notes in microphone and speech recognition system.

write short notes on "digital camera and video camera".what is audio input and audio input device?write short notes in microphone and speech recognition system.

Digital camera A digital camera is an input device. it is used to capture(or take) pictures and stores them in digital form. it does not use... 10:44

Digital camera
A digital camera is an input device. it is used to capture(or take) pictures and stores them in digital form. it does not use traditional camera film. it uses a light-sensitive processor chip to capture photographic images in digital form. these images are stored on a small diskette inserted in  the camera or on flash memory chip. the stored pictures or photographic images can then be loaded in the computer from the disk (or flash memory chip) for further processing.
Video Camera
The process of entering video data into a computer is called video input. Video input consists of motion pictures or movie films. the devices that are used to enter video input into computer are called video input devices.

Video camera is a video input device. it is used for recording video (i.e. movie films)and images of any type. the video and images are recorded in digital form. the recorded videos or images can be transferred into the computer by directly connecting the video camera to a USB port on the system unit.
Audio and Audio input device
Audio input is the process of entering any sounds into the computer. it may include speech, music etc. the device that is used to enter/record sound(audio input ) into computer is called audio input device.
Microphone


Microphone is most commonly used an as audio input devices. it is used to enter sound (or voice) into the computer. it is connected with computer through sound card. A sound card receives sound from microphone in analog form and converts it into digital form. So the sound is stored inside the computer in digital form.
Speech-Recognition system
A system that coverts the voice in to text of commands is known as speech recognition system or voice recognition system. in this system , a microphone is used as an input device.

Speech recognition system allows as user to use voice as input. the user speaks through microphone to give commands to computer such as opening programs, printing, document, shutting down the computer, saving the document etc.

Speech recognition system are not commonly used due to English language pronunciation and limited vocabulary.

what is mouse?describe its functions.

what is mouse?describe its functions.

MOUSE Mouse is the most commonly used pointing input device. it is used to control the cursor or pointer on the screen and give commands to ... 04:28

MOUSE
Mouse is the most commonly used pointing input device. it is used to control the cursor or pointer on the screen and give commands to the computer. it is very easy to use the mouse is attached with the computer by a cable or wireless connection.

the top of mouse contains one wheel and 2 or 3 buttons. these buttons can be clicked or double clicked to perform different task. For example, an object (icon) on the screen is elected by clicking the left button of mouse. similarly, a program or folder is opened by double clicking the left button of mouse.

Types of Mouse
the most popular types of mouse are as follows:
1)  Mechanical Mouse:   it has a small ball at the bottom the ball rotates as the mouse is rolled aver a flat surface. Usually, a rectangular rubber pad ( known as mouse pad) is used as flat surface. As the mouse is rolled over the flat surface, the pointer moves in the same direction on the screen.
2)  Optical Mouse:  it has no ball at the bottom.it uses the laser technology to detect the mouse movement. Nowadays, it is commonly used in personal computers(PCs).


Trackball
A trackball is a pointing input device. it performs functions like a mouse but it is a stationary device. it has a movable ball on its top. the ball is rotated or rolled with fingers( or palm of the hand) to move the pointer on the screen.Like mouse, a trackball also has button used to send the commands to computer.
Touch Pad
Touch Pad is a pressure-sensitive pointing input device. Touch pad is also known as touch pad. it is also stationary device like trackball but it has no moving parts. it is a small, flat surface (or sensitive pad) over which a user slides fingertip to move the pointer on screen. touch pad also has one or more buttons. these buttons are located near the pad. these button work like mouse buttons. touch pad is normally used with laptops.

what is keyboard?describe the enhanced keyboard and its segments.

what is keyboard?describe the enhanced keyboard and its segments.

Keyboard Keyboard is the most commonly used input device. it is mostly used to enter text and numeric type data into the computer. the butto... 07:21

Keyboard
Keyboard is the most commonly used input device. it is mostly used to enter text and numeric type data into the computer. the buttons on the keyboard are called keys.the keyboard contain keys for all alphabetic characters. numeric s digits, and special characters. it also contains some special keys known as function keys. a standard keyboard contains more then 100-keys. the standard keyboard is also QWERTY keyboard. this is because the first six leftmost keys on the top row of alphabets are Q,W,E,R,T and Y. the standard keyboard is shown in figure below.

Parts of keyboard
the keys of a standard keyboard can be divided into following four parts:
1)   Function Keys
2)   Main Keyboard
3)  Numeric Keys
(1)Function keys
there are 12 function keys on the top of keyboard that are labeled  as F2,........,F12. these keys are used to perform special functions. the function of each function key depends upon the software being used on the computer. when a function keys is pressed, a command is sent to the computer. for example, in many software's, the function keys F1 is used to get help about the software currently running on the computer.
(2) Main Keyboard
the main keyboard area is like a typewriter keypad. it includes alphabetic character keys, numeric  keys and some special command keys. the function of command keys depend upon the software being used on the computer. some of the most commonly used command keys are:
Esc:   Usually, this key is used to cancel the current action or  task that is being performed on the                                                                                                                                        computer.
Tab:   it is used to insert a tab(space of 6 or 8 characters) into a document from the current position of cursor.
CAPS LOCK:   it is used to change lowercase letters mode to uppercase and vice versa. the number and symbols are not effected.
SHIFT:    it is used to type some uppercase letters if you are typing in lowercase mode and vice versa. similarly some keys have two symbols printed on them. by default, lower printed symbol or letter is type. To type, the upper symbol, the Shift key is pressed in conjunction with that key.
Ctrl:     Ctrl stand for control. it is used in combination with other keys to apply commands to the computer. for Example, in many applications Ctrl + S shortcut is used to save the current document.
Alt:     Alt stand for Alternate. it is also used in combination with other keys to apply commands to the computer.
Backspace:   Backspace is used to delete  a character to the left of the cursor. the cursor is moved one position backward after deleting the character.
Enter:         Enter key is used to insert new line or paragraph into a word document (or any text editor). it is also used to perform a selected command or action.
(3) Numeric Keys
this part of keyboard consists of numeric keys and arithmetic operator keys. these keys are usually located on the right of the keyboard. these keys are similar to calculator keys. this part of keyboard also has an extra Enter key and Num Lock key. the Num Lock key is used to activate or de-activate the numeric keyboard.
when the computer is in Num Lock mode, these keys are used to enter numeric data and mathematical operators (such as /, *, _ , + ,).

what is I/O processor?

what is I/O processor?

I / O PROCESSOR I/O processor is separated from the  main processor or CPU. it handles the input/output devices. ti also controls the transf... 09:03

I / O PROCESSOR
I/O processor is separated from the  main processor or CPU. it handles the input/output devices. ti also controls the transfer of information between the computer is main memory  and input/output devices.

there are many input/output devices like keyboard, mouse, scanner, monitor, printer,plotter, microphone, video camera, disk drivers etc. the functions of these devices are different from each other. the I/O devices are also slower as compared to the speed CPU  and primary storage. it is because the speed of I/O devices depends upon the mechanical movement of the components of the devices. it is difficult for CPU to control these devices directly.

the I/O processor handles all I/O operations without the involvement of CPU. CPU perform other different operations, instead of I/O operation. it means that CPU and I/O processors run parallel. Most of the computers have one or more I/O processors.
INPUT
anything given to the computer is called input. the data and instructions are given to the computer as input.
Input Devices
the devices that are used to enter data and instructions into the computer are called input devices. the input devices is a hardware component. it takes input from user and converts it into a form that a computer can use.

A list of most popular and commonly used input devices is as follows:
Keyboard
Mouse
Trackball and Touch pad
Scanners
Video camera
Microphone
Character-recognition devices.

what is software? describe the main categories / types of software.

what is software? describe the main categories / types of software.

SOFTWARE a set of instruction given to the computer to solve a particular problem ( or to perform a specific task), is called software. Soft... 20:34

SOFTWARE
a set of instruction given to the computer to solve a particular problem ( or to perform a specific task), is called software. Software is also called computer program.  

Software tells to the computer what to do and how to do. therefore, a computer preform different operation according to the given instruction. Software is developed in computer programming language.
note:best example of software in real life is human soul whereas body is example of hardware.
Types of software
1-   System software 
A program or set of programs that is especially designed to control different operations of computer system is called system software. it control the working of different components of the computer. the system software also enables the other application programs to execute properly.
the examples of system software are:
operating systems.
Utility programs.
Device Drivers.
Language Processors.
Application software
A program or set of programs that are especially designed to solve the specific problems of user, are called application software.it is also known as software package for application package.
Application software is normally available as a package. it consists of the following:
the software supplied on CD-ROM or Floppy disk.
A manual that explains how to use the software.
Training material supplied on CD-ROM or in a booklet.
Categories of Application software
the application software is divided into two main categories:
1-   Custom-built software
2-    Packaged software
1-     Custom-built software
the software that is developed for a particular customer or organization is called custom-built software.it is also known as customized software. for example, software developed to maintain the the records of students of a particular college is an example of custom-built software.
2-    Packaged software
the software that is developed for sale to the general public is called packaged software. packaged software is used to solve some common problem of many people or users.

best example of packaged software is MS-Office that consists of following software's/applications:
word processing software such as MS-Word
Spreadsheet software such as MS-Excel
Outlook for sending and receiving emails
PowerPoint for making presentations.

what is computer hardware? briefly describe the basic hardware devices or components of a computer system?

what is computer hardware? briefly describe the basic hardware devices or components of a computer system?

Hardware The physical components of a computer are called Hardware. You can touch, see and feel hardware. the input/Output devices (such as ... 21:51

Hardware
The physical components of a computer are called Hardware. You can touch, see and feel hardware. the input/Output devices (such as keyboard, Mouse, Printer, Monitor), CPU, Memory unit etc. are example of hardware.

the basic hardware components of computer system are shown in the following figure.
A brief description about basic components of a computer system is as follows:
1-   Input device
         the data and instructions are given to the computer as input. the input device is used to give input to the computer. It accepts input (data & program instruction) in a from that a computer can use. the most commonly used input devices are keyboard, mouse, scanner, microphone etc.
2-   Processor
         Processor is the most important component of the computer. it is also known as central processing Unit(CPU). it is considered as the brain of the computer. it processes (or manipulates) input data according to the given instruction, and converts it into useful information. it is further divided into two main components: these are Control Unit(CU) and Arithmetic Logic Unit (ALU).
3-   Memory Unit
       the memory unit is another important part of computer. it is used to store data and instruction that are currently in use. the main memory or REM is an example of memory unit.
4-    Output Device
        the processed data is also known as output. the output device is used to get output from the computer. it gives processed data or results in  form that a user can understand.the commonly used output devices are monitors, printers and speakers.              
 5-     Secondary storage device
 it is used to store data and programs permanently for later use.the commonly used secondary devices are hard disk,USB drivers,floppy disk,CD-ROM etc.
6-      Bus interconnection
           a bus is electrical path on motherboard.it consists of 8,16,32,or 64 parallel wires.it links different components or devises on motherboard.the data,instructions or control signals flow from one component of computer to  another through bus.    

what is information technology?explain by the ICT?

what is information technology?explain by the ICT?

Information Technology   The technology used for processing, storing, and communication information is called information technology or IT. ... 23:37

Information Technology
  The technology used for processing, storing, and communication information is called information technology or IT. it is the combination of telecommunication technology and computer technology ( hardware and software). it combines computing with high-speed communication links for carrying data form one place to another, all over the world. the website is a type of information technology.

Followings are major components of information technology.
1-    Data or information
2-    Medium or communication Network
3-    Computer hardware and software
the world has become a global village due to information technology. The global village means that people living in the world known each other as if they are living in a village. people can exchange information or messages in such a manner as if they are sitting in a drawing room, face to face.

ICT

     ICT stands for information and communication technology. Now-a-days IT has been replaced with ICT. it is the combination of computer technology, Easiest way of working using some techniques and machines is called technology.

telecommunication or telephonic technology and wireless technology/Mobile. ICT consists of IT, broadcast media, all types of audio and video processing and transmission and network based control and monitoring functions.

what is data? Explain with example. also describe different types of data.

what is data? Explain with example. also describe different types of data.

DATA:               a collection of raw facts  and figures related to an object is called data. an object may be a person (or student), an o... 10:09

DATA:
              a collection of raw facts  and figures related to an object is called data. an object may be a person (or student), an organization, or any other things. Data is collected for  a specific purpose. A piece of data is known as data items. the data items may be a name , a price, a quantity, a code number, mark of student etc.
the word 'raw' means unprocessed. data does not give clear and proper meanings. So it cannot to used directly for decision making. Data can be processed to produce meaningful information.
Types of Data:
      Different types of data are as follows:
Numeric:
                                 Numeric data consists of digits from 0 to 9, +(plus), -(minus) sign and a decimal point.numerical data can be of real type data.
Integer numbers:
                                  it consists of positive or negative whole values.Examples of integer data are 420,302,+62, and -26.
Real Numbers:
                             it consists of values that have decimal point.Examples real data are 15.4, .006, 4.07, and -6.27.
2. Text
               Text data consists of words, sentences, and para-graphics etc. it may consist alphabets, numeric digits and special characters. examples of text data are 'Muhammad Umar', "i love Pakistan", and "475, satellite town, sarghodha".
3.   Image
                     Image consists of charts, graphs, pictures and freehand drawings. for example rise and fall of temperature during a day can be represented by a chart.
4.   Audio
                   Audio consists of music, speech or any other sound or voice. the audio data is the form of continuous signals. it is converted into digital form before entering into computer.
5.    Video
                      Video consists of motion pictures or movie films. then movie films are made using video camera.

Explain by the windows-IV?what is to see disk, directory or file?

Explain by the windows-IV?what is to see disk, directory or file?

WINDOWS - IV:                               by now you must be familiar with the windows and accessories. you also would know how to handle ... 22:38

WINDOWS - IV:
                              by now you must be familiar with the windows and accessories. you also would know how to handle the paintbrush and Word Pad. you also would probably have picked up a computer game and enjoyed it with your computer teacher.


you may also by in a position to do various things on the computer and able to create,  move or delete folders. you have to be mentally alert and up-to-date it your knowledge of computer to ensure that you do not make any mistakes and that you do not spoil or destroy any program or data from the disk.

TO SEE DISK, DIRECTORY OR FILE:
                                                              if you are on windows 98 desktop and you want to see which programs are installed in your computer then:
1.   press start button.
2.    click on programs.

now each icon of the program can be seen through which we can know which program is installed in the computer in windows 98.if you want to know what disk drive are present in your computer and which external device are connected to your computer, then you can=an see it by the procedure given below:
1.   Double click on my computer icon. on the above screen, it is displayed, how many disk drive s are installed in your computer. now you can check how many directories are available in a disk.
2.    Double click on the icon of disk drive, the contest of which you want to see. for example, you can double click on (C:).
As a result the directories (folders) present in that disk appear on the screen.

what is CD-ROM?define by the microphone and modem?

what is CD-ROM?define by the microphone and modem?

Microphone:                           you must be familial with the microphone that is used with the public address system at public functio... 01:37

Microphone:
                          you must be familial with the microphone that is used with the public address system at public functions. the microphone that is also called a mike is used to convert the speech or voice into electronic signals that can be carried through cable to any distant place. the same microphone can be used with the computer also if your computer has a sound sandblaster.

when you speak on the microphone your voice changes into electronic signals ans goes into the computer. thus you can record your voice in the computer and you can even add various effects in it like echo.
CD-ROM:
                  compact disk-read only memory is a disk that holds the computer programs as well as the audio and video. to run a audio, video or program CD you must have a CD-ROM drive (A machine that plays the CD) in your computer.

1. if you want to see a movie or film or your want to add some new software into the computer, or your want to learn some software, etc., then you can insert the video CD related to that topic into the CD-Drive and play it to get your work done.

MODEM:
                   MODEM is short form of modulator and demodulation. this is used to convert the computer (Digital) signals into telephonic (Analog) signals that can be carried through telephone lines to any distant place. On the other end the modem convert them into their original form (Digital).
Thus MODEM behaves as a matador between two or more computers. if your computer is connected with the network or internet, the MODEM will play a very important role in data communication.

what is printer?explain by the scanner and speaker?

what is printer?explain by the scanner and speaker?

PRINTER:                the printer is a machine connected to the computer to print the output on paper. there are different types of printe... 20:30

PRINTER:
               the printer is a machine connected to the computer to print the output on paper. there are different types of printer, which work on different technologies. Dot Matrix, inkjet and laser printers are very popular technologies which are in use now-a- days.

A Dot matrix printer (DMP) is used for quantity and not for quality printing. This is an economical printer, and used by data processing centers and schools. inkjet printer is used in offices where co-lour printers are needed for demonstration or presentation. it is not very costly but still expensive because after about 500 copies the co-lour cartridge is to be replaced. ho-were, for co-lour prints this printer is very popular in the market.

laser printer is the fastest and the best quality printer but it is very costly. they are useful in publishing houses. the printing technology is similar to that of the xerox machine so the text or graphics printed by this printer are very clear and shop. the printed matter of this page is an example of the laser print.
SCANNER:
                   the scanner is a graphic input device. this device is specially used to transfer pictures and photographs into the computer directly. for the picture or photograph that you want to get into the computer for editing, first put it in the scanner and then, by using some commends, you can get it on the computer screen.
SPEAKER:
                 the speech that you have recorded in the computer can be listened to by using speakers. speakers convert the electronic signals into the audio (sound). if you want to listen any music or song, you can insert  the audio CD or CD-ROM drive and play it. thus you can listen the music or song through the speaker.

what is the meaning of the word peripherals? what is the use of the mouse?

what is the meaning of the word peripherals? what is the use of the mouse?

                  THE PERIPHERALS the word peripherals means things placed around any device when we talk about the computer, technically we... 01:50

                  THE PERIPHERALS
the word peripherals means things placed around any device when we talk about the computer, technically we talk about the system unit or CPU rest of the parts which are put around the computer and connector and connected to it are known as peripherals.
there are numbers of peripherals used with the computers. so we should know about some of the important peripherals.
KEYBOARD:
                        the keyboard is a very essential peripheral to work with the computer. it is used to enter words and numbers into the computer just like typing on an electronic typewriter. all the available keyboards are similar in function but the layout can be different hence they can hold 101, 102, 104, 105, 106 or 108 keys.
MOUSE:
                  Mouse is a pointing device. it looks like a small soap case and has a cable that looks like the tail of a mouse. it does not looks like a mouse but it is called a mouse due to its quick movement on the screen. a tilt arrow represents the mouse on the screen which is known as pointer.

when you skip (drag) the mouse on the mouse pad, the pointer moves on the screen accordingly.this is after placing the pointer on any option. you can press the click button of the mouse which will work as you have typed the command on the keyboard and press the Enter key.
MONITOR:
                      the monitor, which looks like a portable television, is the main output device of the computer. it keeps an eye on each and every movement happening in the computer and displays them on the screen. all the inputs and outputs can be seen on the monitor screen. Moreover the message given by the computer can be seen which helps us in correcting mistakes.

all the modern monitors are based on VGA (Video Graphic Array) technology that provides very good quality of display. your monitor is mono chrome (black and white) or color, it must be controlled with VGA card installed in your CPU. Otherwise you will not be able to run the latest software.

what is ip address? explain by the displaying icon local area network.

what is ip address? explain by the displaying icon local area network.

DISPLAYING ICON LOCAL AREA NETWORK:                                                                       let us open of the computers which... 03:09

DISPLAYING ICON LOCAL AREA NETWORK:

                                                                      let us open of the computers which is physically connected. first of all, let us display the icon at the notification area that shows the information about the LAN which the respective computer is connected to.

 for this:
1.   click on start menu.
2.    click on my network places.
3.     click on view network connections.
2.      select and right click the local area connection.
5.     click properties ( this will display the properties window of local area connection).
6.     check right the box with the statement 'show icon in notification area when connected'.
7.     click OK.

now when your computer is connected to the network, the icon will be visible in the notification area.
local area connection is now connected at speed of 100 Mbps. let us example  some interesting information about the local area network ( LAN ) with the help of this icon.

at any time, if you will place the cursor on this icon, (for few seconds), it will tell you that:
1.    it is an icon for local area network.
2.     its speed is 100 Mbps
 LAN is currently connected.

the display window will provide you the following information:
1.   LAN is connected.
2.     now long this computer has been connected  to the network (duration).
3.     speed.
4.     this is the information about the activity of LAN. it tells how many pakets of information have been sent and received a computer.
5.     properties is clicked to explore the properties of connection(discussed latter).
6.      you have can disable the network connection of a computer by clicking tab.

IP ADDRESS:
                   now let us revise some of the topics we learnt in classes.
1.     select 'support' tab by clicking on it.
2.     just like phone numbers, every computer needs a unique number in a network. this unique number is actually the IP Address assign to the computer.
computer needs a language to communicate with others. do you remember this we discussed in classes? intact, this the language used by the network.  this language is known as protocol.
3.   to view the protocol used by your network:
click on general tap the click properties. the are several other information available here but they are beyond the scope of this book. so we shall not discuss them.

if the icon at the notification area is showing that LAN is working, it doesn't mean that now you can use it for data or resource sharing.

do you mean by print command with mathematical operators?

do you mean by print command with mathematical operators?

PRINT COMMAND WITH MATHEMATICAL OPERATORS:        in LOGO, there are four basic mathematical operations that can be performed:     OPERATION... 07:25

PRINT COMMAND WITH MATHEMATICAL OPERATORS:
       in LOGO, there are four basic mathematical operations that can be performed:
    OPERATION                                                                                               OPERATORS
Addition                                                                                                                  +
subtraction                                                                                                             _
Multiplication                                                                                                           *
Division                                                                                                                      /
let's use each operator and see how it will be used with the PRINT primitive.
Addition (+):
                        addition command is used when two (or more) numbers need to be added.
syntax:                  PRINT < nl > + < n2>
where <nl > and <N2> are two numbers that will be added to find their sum.
example:         PRINT   2+3    =5
you can have as many numbers to add as you want, as shown in figure 2.
SUBTRACTION ( _ ):
                                  subtraction command is used when difference of two ( or more ) numbers needs to be found.           PRINT < nl > - < 2l >
where <nl> and <n2> are two numbers that will be subtracted to find their difference.
example,           PRINT 30 _ 20 =   10
you can have as many numbers to subtract as you want, as figure 3 shows.
Multiplication ( * ):
                                   multiplication command is used to multiply two ( or more ) numbers.
syntax:                          PRINT < NL > * < N2 >
EXAMPLE,                      PRINT 5 *6 =      30

Division ( / ): 
                       Division command is used to divide the first number by the second.
Syntax:                                      PRINT <NL> / <N2>
where <nl> is the dividend and <n2> is the divisor.
example:                         PRINT 30/6 =     5

Make changes in the following program and see what different sound can be produced:make ''zing [ ] repeat 50 [make ''zing Iput rep-count *10 :zing make ''zing iput 100 :zing] sound:zing.

Make changes in the following program and see what different sound can be produced:make ''zing [ ] repeat 50 [make ''zing Iput rep-count *10 :zing make ''zing iput 100 :zing] sound:zing.

Use index searches to find appropriate topics: LOGO Help is complete resource for a new (LOGO) user,or an expert. It contains command syntax... 20:42

Use index searches to find appropriate topics:
LOGO Help is complete resource for a new (LOGO) user,or an expert. It contains command syntax's,practical advice,tutorials,and demonstrations to help you learn new things bout LOGO.The Table of Contents,like the TOC of this book,is used to find the topic of your interest .

It consist of three parts:                  
1.   Getting Started:This is the shortest section of LOGO help topics.It contains 'Why LOGO'and                     'Where to Start' sections.They  give a brief introduction of LOGO, and simple examples containing commands/primitives for beginners.
2. using the graphical user interface: this section consists of five subheadings, which help LOGO user to understand and get familiar with its GUL.
3.    using the language: this is the longest section in LOGO help topics. it contains details of how to use the LOGO language.

this section consists of advanced primitive and functions that help programmers write batter programs.
if, for any reason, you not able to locate your LOGO topics, an index search will help you find your desired information.
let's take an example.  you come across the following program:
make "zing [ ]
repeat 50 [make ''zing Iput recount* 10 :zing make ''zing Iput 100 :zing]
sound :zing
now, be the looks of the program, you know that it will make some kind of sound. you are familiar with LOGO primitives such as 'repeat' and 'sound'. but you have not come across primitives such as 'make',Iput' and 'recount'. this is where the LOGO index comes handy.

let's take the primitive 'recount' and see how a find its usage and syntax.
1.     open the 'help' menu.
2.       click on 'index'.
3.        enter 'recount' (via keyboard). as you types, the index  display area will keep on changing, until your desired topic is displayed.

what is formatting hard disk?deference between VIRUS and WORM?

what is formatting hard disk?deference between VIRUS and WORM?

FORMATTING HARD DISKS:                                                       the primary storage devices on a computer are hard disk. they n... 23:03

FORMATTING HARD DISKS:
                                                      the primary storage devices on a computer are hard disk. they need to be formatted before they can be used.formatting a disk means to prepare the disk with a file system so that windows can store information on the disk.(A file system is a method for storing and organizing computer files.) hard disk in new computers running windows are already formatted. if you purchase an additional hard to expand the storage of your computer, you may need to format it.
please remember  that formatting arrases any existing files on a hard disk. if you format a hard disk that has files on it, he files well be deleted, so be careful.
MAKING BACKUPS:
                                       as the name suggests, a file backup is copy a file that is stored in a separate location form the original. backing up our files helps to protect them form being permanently lost or changed in the event we accidentally delete them. VIRUS and WORM attacks and software/hardware failures are other reasons why we need to backup our files. if any of these accidents occur and your files are backed up., you can easily store them.
we should back up anything at would be difficult or impossible to replace, and do it on a regular basis. pictures, videos, documents and records are examples of files that should be backed up.
RESTORING SYSTEM TO PREVIOUS DATES:
                                                                              a load of viruses (and worms, etc.) attack system file. damage to the file is so great that they connect be saved. sometime, while installing software, an unexpected error
  in the computer may cause it to behave strangely. the problem is not even fixed softer the software is uninstalled.the only solution is to restore the system to a previous date.
system restore, a feature of MS windows, regularly creates restore points. these points are saved by data and time, using the system clock. they contain information about system settings, and other information that windows uses. system restore does not affect personal file such as e-mails, documents and photos.

deference by computer hardware and software?explain by introduction to hardware?

deference by computer hardware and software?explain by introduction to hardware?

INTRODUCTION TO HARDWARE :                in the previous class we have already studied the definition of computer and its basic components,... 08:38

INTRODUCTION TO HARDWARE :
               in the previous class we have already studied the definition of computer and its basic components, we will review them here.
"A computer is an electronic machine which processes raw data  (Input) into meaningful information (output) and also stores output for later use."
A computer works with the help of its components. The components of  a computer consist of hardware and software.
       Components of a computer
1.  Software
2.  Hardware

SOFTWARE:
                      Software is the set of instructions given to the computer to perform specific task. A software is also called a computer program. For example , Microsoft windows, Ms word, core draw, device drivers, etc.
HARDWARE:
                       The physical parts of the computer that we can see and touch are known as hardware. These include the input and output devices as well as the system unit.
. Input devices:
                           Devices which are used to enter data Into a computer are known as input devices,e.g. keyboard, mouse, microphone, scan
ner, digital camera, etc.
.   OUTPUT DEVICES:
                                     Devices which are used to display / present output are called output devices, e.g. monitor, printer, speakers, etc.
.    Storage devices:
                                  Storage devices hold data and instructions permanently e.g. floppy disk, hard disk, CD/DVD, USB flash drive, etc.
COMMUNICATION DEVICES:
                                                   Devices which are used to communicate and connect a computer with other computers are known as communication devices e.g. modem.

why are software's installed before use? you make mistakenly installed software that needs to be removed now. mention the three steps that will removed the software from your system.explain by uninstalling software?

why are software's installed before use? you make mistakenly installed software that needs to be removed now. mention the three steps that will removed the software from your system.explain by uninstalling software?

INSTALLING SOFTWARE'S:                                         Most software programs require that you first install them on your comput... 05:49

INSTALLING SOFTWARE'S:
                                        Most software programs require that you first install them on your computer before using them. for example, if you by Microsoft office, you need to install it on your computer before you can run any of the included programs such as MS word or MS excel. you can install software form a CD or DVD, an external hard drive, or from a networked computer.you can also install a program or software update form a file downloaded from the internet.
before installation it is wise to cred a restore point ( discussed later). this saves important computer from damage in the event of computer breakdown. installing a software program writes the necessary data for running the program on your hard drive. installing software is usually a simple process. it involves double-clicking an installer icon and then clicking "I Agree" when the license agreement appears on screen.
you may have to choose what

 directory on your hard disk you would like to install the software in, but often the installer will even choose that for you.
windows vista, the latest OS by Microsoft windows, is also a system software that is installed before use. like many software's, it comes in edition. they are business, home basic, home premium, and ultimate.
UNINSTALLING SOFTWARE'S:
                                                if a software program or game is no longer being used or additional space is required, it may be necessary to uninstall it. remember, uninstall is different from deleting a file / folder. there are software that are simply deleted if their removal is necessary, but they are few. ( the Urdu typing software in-page is an example.) most software have to be uninstalled. file have to be removed not just from the parent folder, but also from other places.
there are utilities in Microsoft windows that allow you to efficiently uninstall software's. in MS windows XP and versions before it, this utility was called " Add or remove programs". in MS windows Vista, it is called "program and features".
the instructions given below, to uninstall software, are for MS windows XP.
1.   Click start, click control panel, and then double-click add or remove programs.
2.    in the currently installed programs box, click the program that you want to remove, and then click remove.
3.     if you are prompted to confirm the removal of te program, click yes.