HOLIDAY HOMEWORK

6TH CLASS

1.INPUT AND OUTPUT DEVICES PICTURES

2.DIFFERENT PRINTERS PICTURES

3.COMPONENTS OF COMPUTER DESCRIBE AND PASTE THE PICTURE

SUBMIT TO THE MAIL ID K.VASUKI@YMAIL.COM, VASUKIKPGT@GMAIL.COM

7TH CLASS

1ST UNIT TOPICS SELECT YOURSELF AND DO PPT OF MINIMUM TEN PAGES.

SUBMIT TO THE MAIL ID K.VASUKI@YMAIL.COM, VASUKIKPGT@GMAIL.COM

8TH CLASS

1ST AND 2 AND UNIT TOPICS DO PPT BY SEARCHING THROUGH NET OF MINIMUM 10 PAGES.

SUBMIT TO THE MAIL ID K.VASUKI@YMAIL.COM, VASUKIKPGT@GMAIL.COM

9TH CLASS

PHOTOSHOP TOOLS AND MULTIMEDIA FLASH TOPICS GIVEN IN SYLLABUS , DO PPT OF ALL TOPICS AND SUBMIT TO THE MAIL ID K.VASUKI@YMAIL.COM, VASUKIKPGT@GMAIL.COM

10TH CLASS

UNIT 2 TOPICS DETAILS COLLECT INFORMATION FROM NET AND DO PPT .

SUBMIT TO THE MAIL ID K.VASUKI@YMAIL.COM, VASUKIKPGT@GMAIL.COM

 

SYLLABUS

class_III_to_X_computer_syllabus

3D MAX AUTODESK

Autodesk 3ds Max, formerly 3D Studio, then 3D Studio Max is a professional 3D computer graphics program for making 3D animations, models, games and images. It is developed and produced by Autodesk Media and Entertainment.

Viewing and Navigating 3D Space

Everything in 3ds Max is located in a three-dimensional world that you view through one or more viewports . You have a variety of options for visualizing this enormous stage-like space, from the tiniest details to the full extent of your scene.

Using multiple viewports can help you visualize the scene. Here, the largest viewport shows the view from the camera depicted in the other viewports.

Basics of Creating and Modifying Objects

The Create panel contains controls for creating new objects, the first step in building a scene. Despite the variety of object types, the creation process is consistent for most objects. Typically you create objects interactively with the mouse; alternative methods are available. For details, seeCreating an Object.

The Modify panel provides controls to complete the modeling process. You can rework any object, from its creation parameters to its internal geometry. Both object-space and world-space modifiers let you apply a wide range of effects to objects in your scene. The modifier stack allows editing of the modifier sequence.

Keyframes/Keys

Keyframes record the transition points in the animation of any element in the scene, such as the motion of an object or the bend amount applied by a modifier. The values at these keyframes are called keys.

The red boxes indicate keyframes, the dotted line shows the interpolated trajectory.

Controllers

Controllers, like constraints, handle the animation tasks in a scene. They store animation key values and procedural animation settings, and they interpolate between animation key values.

The animation controllers are organized in the following categories:

• Float controllers: for animating floating-point values
• Point3 controllers: for animating three-component values such as colors or 3D points
• Position controllers: for animating positions of objects and selection sets
• Rotation controllers: for animating rotation of objects and selection sets
• Scale controllers: for animating the scale of objects and selection sets
• Transform controllers: for animating general transforms (position, rotation, and scale) of objects and selection sets

Parameter/Parametric

A parameter is a setting or value that you can change. Many objects in 3ds Max have parameters that you can change to alter the size or shape of the object. This type of object can be described as parametric.

A tube is one example of a parametric object. Varying its parameters creates varying geometry.

Animating Transforms

You can animate changes in position, rotation, and scale (transforms) by turning on the Auto Key button and then performing the transform at any frame other than frame 0. This creates a key for that transform at the current frame.

Example: To animate an object moving among three points:

1. Turn on . (See Using Auto Key Mode.)

   The Auto Key button, the highlight border around the active viewport, and the time slider background all turn red.

   
2. Drag the time slider to frame 25.
3. Move the object from its current position (point A) to another location (point B).

   3ds Max creates Move keys at frames 0 and 25. These appear on the track bar. The establishing key at frame 0 describes the object’s original position, at point A. The key at frame 25 describes the object’s position at point B.

4. Drag the time slider to frame 50.
5. Move the object from point B to a third location (point C).

   3ds Max creates a Move key at frame 50 that describes the object’s position at point C.

6. Click to stop recording animation.
7. Click (Play).

   The object moves from point A to point B over frames 0 to 25, and then proceeds to point C over frames 26 to 50.

8. The Play button has turned into a Stop button; click (Stop) to stop playback.

 ACCELERATION

To have delegate acceleration considered for motion synthesis, turn on Use Acceleration, choose Range or Unique, and then make the appropriate settings.

Time Configuration

The Time Configuration dialog provides settings for frame rate, time display, playback, and animation. You use this dialog to change the length of your animation, or stretch or rescale it. You also use it to set the start and end frames of the active time segment and your animation.

• Status bar > Time controls > Time Configuration > Time Configuration dialog
• 

Play/Stop

The Play button plays the animation in the active viewport. If you click another viewport to make it active, the animation continues playing in that viewport. When the animation is playing, the Play button becomes a Stop button. The Play button is a flyout for playing only the animation of selected objects.

• Status bar > Time controls > (Play Animation)
• Status bar > Time controls > (Stop Animation)
• Keyboard > / (to play) (3ds Max mode)
• Keyboard > .)+V (Maya mode: See Interaction Mode Preferences
• Keyboard > (to stop)

• Time Configuration

• The Time Configuration dialog provides settings for frame rate, time display, playback, and animation. You use this dialog to change the length of your animation, or stretch or rescale it. You also use it to set the start and end frames of the active time segment and your animation.
  • Status bar > Time controls > Time Configuration > Time Configuration dialog
  • 

Understanding Walk Cycle Constraints

Walking motions in both freeform and footstep animations should follow the rules of certain IK constraints. In both freeform and footstep animation, a footstep interval is the start and end of a sequence of IK constraints in world space, with IK Blend set to be greater than 0.0. A biped foot in the Move state should have body space turned on with an IK Blend of 0.0. By using these IK constraints, you can convert between the two animation methods seamlessly.

In a freeform walking animation, typically you need two key types for the legs:

• If the foot is planted on the ground, the key must have IK Blend=1.0 with Object Space and Join To Prev Key turned on.
• If the foot is in the air between footsteps, then IK Blend=0.0 with Body Space turned on, and Join To Prev Key turned off.

• Animating Links

• To animate the links for the ball:

  1. On the Motion panel, assign a Link constraint as the ball’s Transform controller. You can also put a Link constraint on the ball from the Animation menu by choosing Constraints Link Constraint.
  2. Go to frame 0, then on the Motion panel, click Add Link, and click the hand holding the ball. The ball will now move along with the hand, as if it were linked to it.
  3. Drag the time slider to frame 50, where you want the second hand to pick up the ball, click Add Link, then click the second hand. From this frame on, it’s as if the ball were linked to the second hand.

  When you play back the animation, the ball travels with the first hand until frame 50, where you added the second link, then the ball is passed to the second hand for the rest of the animation.

  

  Robot arms pass a ball from one hand to the other.

  Modifiers

  Modifiers, as the name implies, modify an object’s geometrical structure, deforming it in some way. When you apply a taper modifier to the end of a cylinder, for example, the vertices near the end move closer together. Modifiers make changes in the geometry that stay in effect until you adjust or delete the modifier.

  

  Example: effects of the twist modifier on an object

  Edit Modifiers and Editable Objects

  To achieve highly detailed modeling effects, you can directly transform, modify, and align the geometry of objects at a sub-object level, using the Modify panel. The following table shows the different object types and their respective sub-objects.

  Object Type	Sub-Object Geometry
  Mesh	Vertex, Edge, Face, Polygon, Element
  Poly	Vertex, Edge, Border, Polygon, Element
  Spline	Vertex, Segment, Spline
  Patch Surface	Vertex, Edge, Patch, Element, Handle
  NURBS Curve	Curve CV or Point, Curve
  NURBS Surface	Surface CV or Point, Surface

  With the exception of NURBS objects, to gain access to an object’s sub-objects, in most cases you must first either convert the object into an editable object, or apply any of various modifiers to the object, such as Edit Mesh/Poly/Spline/Patch or Mesh/Poly/Spline Select. The Select modifiers simply let you specify sub-objects for modification by subsequently applied modifiers. The distinctions between transforming an object into an editable object and applying an Edit modifier to it are as follows:

  Method	Advantage	Disadvantage
  Editable object	More efficient Can animate sub-objects	Lose creation parameters
  Edit/Select modifier	Keep creation parameters	Less efficient Cannot animate sub-objects (except for limited animation with Edit Poly)

CLASS VIII- UNIT -1 -ALGORITHM

An algorithm specifies a series of steps that perform a particular computation or task.

unit 2 -Flowchart Symbols

Flowcharts use special shapes to represent different types of actions or steps in a process. Lines and arrows show the sequence of the steps, and the relationships among them. These are known as flowchart symbols.

The type of diagram dictates the flowchart symbols that are used. For example, a data flow diagram may contain an Input/Output Symbol (also known as an I/O Symbol), but you wouldn’t expect to see it in most process flow diagrams.

Over the years, as technology has evolved, so has flowcharting. Some flowchart symbols that were used in the past to represent computer punchcards, or punched tape, have been relegated to the dustbin of history.

Flowchart: A graphic representation of an algorithm, often used in the design phase of programming to work out the logical flow of a program.

CLASS IX – UNIT 1- REVIEW OF PHOTOSHOP

PHOTOSHOP IS A POWERFUL TOOL USED FOR EDITING AN IMAGE.

 

Working with files
Opening, saving, and creating new files
Creating new files in Photoshop is easy: click File and then New. Set the height, width, and resolution of the new file in the dialogue box. Opening files in Photoshop is just as easy: the command File>Open can be used to open most graphics files. Once you’ve created or opened a file and edited it, you can save your file in a number of different formats. To save the file in its current format, use File>Save. If you want to save it as a different type, you can use File>Save As. We’ll discuss saving later in the tutorial; for now it’s OK to save your images in their original format.   The Flash Toolbar Let’s start learning about flash toolbox, it has many tools to draw graphic, fill color, gradient color and modify the shape of the drawn by the tools. Some tools have hidden tool that is indicated by a little black triangle shape that is situated right bottom corner of the tools. I have given below every tool’s description so read carefuly. In the tool section in the toolbar, we have different type of tool to make graphic and modification in that. All the tools are fully describe below. Selection Tool: Selection tool helps to select and modify the object shape. We can move any object which we have imported and drawn. We can delete the any part of any formatted picture but remember the picture should be break (To make break picture, press Ctrl + B key). Subselection tool: When we need modification to make different shape of the drown graphic in the document, we need a tool that is Subselection tool. It highlight the anchor point of the graphic by click on that to arrange point and get different shape as required. Free Transform tool: Free Transform tool is very important tool, this tool helps us to scale, reflect of the picture and we can rotate the object from the particuler point. we can also skew of object as per our requirement. Gradient Transform Tool : With the help of this tool you can scale and rotate of the Gradient. When you fill the Gradient on object. Select the Gradient Transform tool or pres F. As you click on Gradient Transform tool a bounding box will appear on the objects. then you can work this bounding box Ex. Moving the gradient, move the focal point. (focal point applicable only Radial gradient.), increase and decrease of gradient, rotate the gradient as required. Lasso Tool : Lasso tool is a free hand selection tool. you can use this tool to select the object as you required and delete. when you select lasso option one magic wand tool and magic wand setting also appear down of the tool pallet, you can change the setting of this tool. Pen Tool: Pen tool used to draw graphics by the anchor points and create line path in the document. Add Anchor Point: We can add the more anchor point on the path and any graphic drawn by any tool by clicking on the path. Delete Anchor Point: We can delete the anchor point on the same way by Clicking on the Anchor Points Convert Anchor Point: We can modify the path with the help of this tool. Text Tool: Select the text tool to type text on the document, click on the document with selected text tool a text area will appeared on the document, write the text on the box. You can scale the text area by scaling and more options will appear on the properties panel. Line Tool: With the help of line tool we can also make the curve path and draw straight line. To make curve graphic we should draw a straight line then make curve by the help of Subselection tool. Rectangle Tool: This section has different type of shape tool to draw shape on the document like Rectangle, Oval, Rectangle Primitive, Oval primitive and polyStar shapes. You can also modify the tool property to get different type of shapes. Pencil Tool: This is a freehand tool that’s used to drawing. when you click on the pencil tool more option will appear bottom of the tool pallet. you can create those shapes also. Brush Tool: It’s also a freehand tool and used to crate drawing and lines in the document. The different mode of the tool are also available in the flash to get different brush effect, select brush tool some more option will appear on the bottom of the toolbar make setting and apply on. Ink Bottle: This tool is used to change the color of stroke color and other options. Paint Bucket: The paint bucket helps us to fill selected color in the selected area and graphic, choose any color from the color pallate and fill by the paint bucket tool. Eye Dropper Tool: Eye Dropper tool helps to pick any color from the picture and graphic, As you want to fill a color that is not in the color pallate, open colored picture and pick color by eye dropper tool and fill anywhere in the document as required. Eraser Tool: This is a eraser tool we can erase the object and unwanted area in the document by five different way, the list is given below. The view section in the toolbox, we have two tool those are used to move the document and zoom picture, the tools are described below. Hand Tool: With the help of hand tool, in the zoom mode of the document it is used to move document on any side or just hold down the space bar and move file with the help of the mouse. Zoom tool: With the help of zoom tool, we can see the the object and picture in the zoom mode and modify on the right place as required and come back to actual size press double click on the zoom tool. The color section in the toolbox, we have two tool those are used to fill stroke and foreground. The tools are described below. Stroke color: When we draw any graphic by the help of any tool, the stroke automatically appear with the graphic with same graphic color. If we want to draw graphic with different stroke color, select stroke color before drawing. Fill Color: First choose foreground color as you want to fill in the graphic then draw graphic on the document, it can also change after the drawing but the tool is given in the toolbar so make first color setting. The animation in Flash

CLASS VII -UNIT 1-COMPUTER SECURITY

THREATS TO COMPUTER

Hacking

Hacking is a term used to describe actions taken by someone to gain unauthorized access to a computer. The availability of information online on the tools, techniques, and malware makes it easier for even non-technical people to undertake malicious activities.

What it is:

The process by which cyber criminals gain access to your computer.

What it can do:

• Find weaknesses (or pre-existing bugs) in your security settings and exploit them in order to access your information.
• Install a Trojan horse, providing a back door for hackers to enter and search for your information.

Malware

Malware is one of the more common ways to infiltrate or damage your computer.

What it is:

Malicious software that infects your computer, such as computer viruses, worms, Trojan horses, spyware, and adware.

What it can do:

• Intimidate you with scareware, which is usually a pop-up message that tells you your computer has a security problem or other false information.
• Reformat the hard drive of your computer causing you to lose all your information.
• Alter or delete files.
• Steal sensitive information.
• Send emails on your behalf.
• Take control of your computer and all the software running on it.

Learn more about protecting your computer.

Spam

Spam is one of the more common methods of both sending information out and collecting it from unsuspecting people. Canada has a new anti-spam legislation that you can learn more about at www.fightspam.gc.ca

What it is:

• The mass distribution of unsolicited messages, advertising or pornography to addresses which can be easily found on the Internet through things like social networking sites, company websites and personal blogs.

• Canada’s anti-spam legislation applies to all commercial electronic messages. A commercial electronic message is any electronic message that encourages participation in a commercial activity, regardless of whether there is an expectation of profit.

What it can do:

• Annoy you with unwanted junk mail.
• Create a burden for communications service providers and businesses to filter electronic messages.
• Phish for your information by tricking you into following links or entering details with too-good-to-be-true offers and promotions.
• Provide a vehicle for malware, scams, fraud and threats to your privacy.

Find out more about email spam.

 

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Spyware

Spyware & Adware

Spyware and adware are often used by third parties to infiltrate your computer.

What it is:

Software that collects personal information about you without you knowing. They often come in the form of a ‘free’ download and are installed automatically with or without your consent. These are difficult to remove and can infect your computer with viruses.

What it can do:

• Collect information about you without you knowing about it and give it to third parties.
• Send your usernames, passwords, surfing habits, list of applications you’ve downloaded, settings, and even the version of your operating system to third parties.
• Change the way your computer runs without your knowledge.
• Take you to unwanted sites or inundate you with uncontrollable pop-up ads.

Learn more about protecting your computer.

 

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Trojan Horses

A Trojan horse may not be a term you’re familiar with, but there’s a good chance you or someone you know has been affected by one.

What it is:

A malicious program that is disguised as, or embedded within, legitimate software. It is an executable file that will install itself and run automatically once it’s downloaded.

What it can do:

• Delete your files.
• Use your computer to hack other computers.
• Watch you through your web cam.
• Log your keystrokes (such as a credit card number you entered in an online purchase).
• Record usernames, passwords and other personal information.

Learn more about protecting your computer.

 

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Viruses

Most people have heard of computer viruses, but not many know exactly what they are or what they do.

What they are:

Malicious computer programs that are often sent as an email attachment or a download with the intent of infecting your computer, as well as the computers of everyone in your contact list. Just visiting a site can start an automatic download of a virus.

What they can do:

• Send spam.
• Provide criminals with access to your computer and contact lists.
• Scan and find personal information like passwords on your computer.
• Hijack your web browser.
• Disable your security settings.
• Display unwanted ads.

When a program is running, the virus attached to it could infiltrate your hard drive and also spread to USB keys and external hard drives. Any attachment you create using this program and send to someone else could also infect them with the virus.

How will you know if your computer is infected?

Here are a few things to check for:

• It takes longer than usual for your computer to start up, it restarts on its own or doesn’t start up at all.
• It takes a long time to launch a program.
• Files and data have disappeared.
• Your system and programs crash constantly.
• The homepage you set on your web browser is different (note that this could be caused by Adware that has been installed on your computer).
• Web pages are slow to load.
• Your computer screen looks distorted.
• Programs are running without your control.

If you suspect a problem, make sure your security software is up to date and run it to check for infection. If nothing is found, or if you are unsure of what to do, seek technical help.

Worms

Worms are a common threat to computers and the Internet as a whole.

What they are:

A worm, unlike a virus, goes to work on its own without attaching itself to files or programs. It lives in your computer memory, doesn’t damage or alter the hard drive and propagates by sending itself to other computers in a network – whether within a company or the Internet itself.

What they can do:

• Spread to everyone in your contact list.
• Cause a tremendous amount of damage by shutting down parts of the Internet, wreaking havoc on an internal network and costing companies enormous amounts of lost revenue.

Boot Sector Virus: Boot sector virus infects the boot sector on floppy disks, hard disks and other bootable media like DVD or CD. The examples of boot sector viruses are – Form, Michelangelo, and Stoned.

Macro Virus: A macro virus is an original individual amongst the types of computer virus, and contaminates the macros inside a pattern. As soon as you release a spreadsheet or word processing text, the macro virus gets into typical pattern. The examples of Macro viruses are – Relax, Babbles, and Melissa.

Companion Viruses: Companion viruses are as same as direct action types or resident types. They are companion viruses as because sometimes they get into the method and accompany the other existing files. The example of accompany viruses are – Asimov.1539, Terax.1069.

ANTIVIRUS

Antivirus (anti-virus) software is a class of program that will prevent, detect and remediate malware infections on individual computing devices and IT systems.

FIREWALL

hacker

a hacker is someone who seeks and exploits weaknesses in a computer system orcomputer network.

cracker

A cracker is someone who breaks into someone else’s computer system, often on a network; bypasses passwords or licenses in computer programs; or in other ways intentionally breaches computer security.

Backup

A backup is a copy of one or more filescreated as an alternate in case the original data is lost or becomes unusable. For example, you may save several copies of a research paper on your hard drive as backup files incase you decide to use a previous revision. Better yet, you could save the backups to a USB flash disk, which would also protect the files if the hard drive failed.

Restore

Restoring a computer, often called a “system restore,” is often done as a last resort to fix a problematic machine. For example, if a virushas infected a large number of system files, a system restore may be the only way to get the computer to run smoothly again.

CLASS VI – UNIT 1 – FUNDAMENTAL OF COMPUTER

 

BRIEF HISTORY OF COMPUTER

A computer is an electronic machine that accepts data, stores and processes data into information. The computer is able to work because there are instructions in its memory directing it.

This picture shows what were known as “counting tables” [photo courtesy IBM]

A typical computer operation back when computers were people.

The abacus was an early aid for mathematical computations. Its only value is that it aids the memory of the human performing the calculation.

A very old abacus

 

 logarithm values were carved on ivory sticks which are now called Napier’s Bones.

An original set of Napier’s Bones [photo courtesy IBM]

A more modern set of Napier’s Bones

Napier’s invention led directly to the slide rule, first built in England in 1632 and still in use in the 1960’s by the NASA engineers of the Mercury, Gemini, and Apollo programs which landed men on the moon.

A slide rule

Leonardo da Vinci (1452-1519) made drawings of gear-driven calculating machines but apparently never built any.

A Leonardo da Vinci drawing showing gears arranged for computing

The first gear-driven calculating machine to actually be built was probably the calculating clock, so named by its inventor, the German professor Wilhelm Schickard in 1623. This device got little publicity because Schickard died soon afterward in the bubonic plague.

Schickard’s Calculating Clock

 

A Pascaline opened up so you can observe the gears and cylinders which rotated to display the numerical result

input unit performs the following functions.

1. It accepts (or reads) the list of instructions and data from the outside world.
2. It converts these instructions and data in computer acceptable format.
3. It supplies the converted instructions and data to the computer system for further processing.

the following functions are performed by an output unit.

1. It accepts the results produced by the computer which are in coded form and hence cannot be easily understood by us.
2. It converts these coded results to human acceptable (readable) form.
3. It supplied the converted results to the outside world.

the specific functions of the storage unit are to store:

1. All the data to be processed and the instruction required for processing (received from input devices).
2. Intermediate results of processing.
3. Final results of processing before these results are released to an output device.

Central Processing Unit (CPU)

The main unit inside the computer is the CPU. This unit is responsible for all events inside the computer. It controls all internal and external devices, performs“Arithmetic and Logical operations”. The operations a Microprocessor performs are called “instruction set” of this processor.

The control Unit and the Arithmetic and Logic unit of a computer system are jointly known as the Central Processing Unit (CPU). The CPU is the brain of any computer system.

Arithmetic and Logic Unit (ALU)

The arithmetic and logic unit (ALU) of a computer system is the place where the actual execution of the instructions take place during the processing operations. All calculations are performed and all comparisons (decisions) are made in the ALU.

Control Unit

It manages and coordinates the entire computer system.

Input Devices:

a)      Graphics Tablets

b)      Cameras

c)      Video Capture Hardware

d)     Trackballs

e)      Barcode reader

f)       Digital camera

g)      Gamepad

h)      Joystick

i)        Keyboard

j)        Microphone

k)      MIDI keyboard

l)        Mouse (pointing device)

m)    Scanner

n)      Webcam

o)      Touchpads

p)      Pen Input

q)      Microphone

r)       Electronic Whiteboard

s) OMR

t) OCR

u) Punch card reader

v)MICR (Magnetic Ink character reader)

w) Magnetic Tape Drive

OUTPUT  DEVICES:

1. Monitor (LED, LCD, CRT etc)
2. Printers (all types)
3. Plotters
4. Projector
5. LCD Projection Panels
6. Computer Output Microfilm (COM)
7. Speaker(s)
8. Head Phone
9. Visual Display Unit
10. Film Recorder
11. Microfiche

Software
Software tells the computer what to do and how to do. A computer performs different operations according to the instruction of software. Software is developed in a computer programming language.

Types of Software
Software can be classified into following two main categories or types
1- System Software
2- Application Software

System Software
A program or set of programs that is especially designed to control different operations of computer system is called system software. It controls the working of different components of the computer. The system also enables the other application programs to excute properly

Operating systems, utility programs, and device drivers are the examples of system software. Operating system is the main and most popular type of system software.

Application Software
A program or set of programs that are especially designed to solve the specific problems of users, are called application software. It is also known as software package

There are Different kinds of application software such as comercial software, scientific software, financial packages, Games, multimedia software.

The computer memory is a temporary storage area. It holds the data and instructions that the Central Processing Unit (CPU) needs. Before a program can be run, the program is loaded from some storage medium into the memory. This allows the CPU direct access to the program.Memory is a need for any computer.

PRINTER

“A printer is an external output device that takes data from a computer and generates output in the form of graphics / text on a paper”.

There are two types of printers.

Impact printers

An impact printer makes contact with the paper. It usually forms the print image by pressing an inked ribbon against the paper using a hammer or pins. Following are some examples of impact printers.

 Dot-Matrix Printers

The dot-matrix printer uses print heads containing from 9 to 24 pins. These pins produce patterns of dots on the paper to form the individual characters. Dot-matrix printers are inexpensive and typically print at speeds of 100-600 characters per second.

Non-impact printers

Non-impact printers do not use a striking device to produce characters on the paper; and because these printers do not hammer against the paper they are much quieter. Following are some non-impacted printers.

Ink-jet printers

Ink-jet printers work in the same fashion as dot-matrix printers in the form images or characters with little dots.

Laser printers

A laser printer works like a photocopy machine. Laser printers produce images on paper by directing a laser beam at a mirror which bounces the beam onto a drum.

Advantages of Laser Printer

• The main advantage of Laser printer is its speed & efficiency at which it prints high-quality quality graphics & text.
• Laser printers produce high-quality output as compared to other printers.
• Laser printers are quite and does not produce disturbing sounds.
• They are also capable to produce color prints.

 Disadvantages of Laser Printer

• The main disadvantage of Laser printer is its cost, they are relatively costly as compared to other printers.
• The maintenance, repair & servicing charges are also high of these printers.
• Laser printers emit small amount of ozone and are hazardous to health and the atmosphere.
•