The ComputerAngeli Reina A. Golpo, BSET

Computeran electronic device for storing and processing data, typically in binary form, according to instructions given to it in a variable program.

Computer

1. It responds to a specific set of instructions in a well-defined manner.2. It can execute a prerecorded list of instructions (a program).3. It can quickly store and retrieve large amounts of data.

Characteristics of Computer

Computer

1. Hardware 2. Software 

1. System Software2. Application Software

3. Firmware

Parts of Computer

HardwareThe collection of physical parts of a computer system. computer case, monitor, keyboard, and mouse. It also includes all the parts inside the computer case, such as the hard disk drive, motherboard, video card, and many others. Computer hardware is what you can physically touch.

Hardware Components

• Central processing unit (CPU)• Memory• Mass storage device• Input device• Output device

Central Processing Unit (CPU)The heart of the

computer, this is the component that actually executes instructions organized in programs ("software") which tell the computer what to do.

MemoryEnables a computer to store, at least temporarily, data, programs, and intermediate results

Mass Storage Device (MSD) Allows a computer to permanently retain large amounts of data and programs between jobs. Common mass storage devices include disk drives and tape drives.

Input DevicesUsually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.

Input DevicesUsually a keyboard and mouse, the input device is the conduit through which data and instructions enter a computer.

Keyboard Mouse Joy StickLight pen Track Ball ScannerGraphic Tablet Microphone Magnetic Ink Card Reader(MICR)Bar Code Reader Optical Mark Reader(OMR) Optical Character Reader(OCR)

Input Devices1. Keyboard is the most common and very popular input device

which helps in inputting data to the computer. The layout of the keyboard is like that of traditional typewriter, although there are some additional keys provided for performing additional functions.

2. Mouse is most popular pointing device. It is a very famous cursor-control device having a small palm size box with a round ball at its base which senses the movement of mouse and sends corresponding signals to CPU when the mouse buttons are pressed.

3. Joystick is also a pointing device which is used to move cursor position on a monitor screen. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions. Use in Computer Aided Designing.

Input Devices4. Light pen is a pointing device which is similar to a pen. It is used to select a displayed menu item or draw pictures on the monitor screen. 5. Track ball is an input device that is mostly used in notebook or laptop computer, instead of a mouse. This is a ball which is half inserted and by moving fingers on ball, pointer can be moved. 6. Scanner is an input device which works more like a photocopy machine. It is used when some information is available on a paper and it is to be transferred to the hard disc of the computer for further manipulation. Scanner captures images from the source which are then converted into the digital form that can be stored on the disc.

Input Devices7. Digitizer is an input device which converts analog information into digital form. Digitizer is also known as Tablet or Graphics Tablet because it converts graphics and pictorial data into binary inputs. A graphic tablet as digitizer is used for doing fine works of drawing and image manipulation applications.

8. Microphone is an input device to input sound that is then stored in digital form. The microphone is used for various applications like adding sound to a multimedia presentation or for mixing music.

9. MICR input device is generally used in banks because of a large number of cheques to be processed every day. The bank's code number and cheque number are printed on the cheques with a special type of ink that contains particles of magnetic material that are machine readable. This reading process is called Magnetic Ink Character Recognition (MICR). The main advantages of MICR is that it is fast and less error prone.

Input Devices10. Optical Character Reader is an input device used to read a printed text. OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.

11. Bar Code Reader is a device used for reading bar coded data (data in form of light and dark lines). Bar coded data is generally used in labelling goods, numbering the books etc. It may be a hand held scanner or may be embedded in a stationary scanner. Bar Code Reader scans a bar code image, converts it into an alphanumeric value which is then fed to the computer to which bar code reader is connected.

12. Optical Mark Reader is a special type of optical scanner used to recognize the type of mark made by pen or pencil. It is used where one out of a few alternatives is to be selected and marked. It is specially used for checking the answer sheets of examinations having multiple choice questions.

Output Device1. A display screen, printer, or other device that lets you see what the computer has accomplished.2. Any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. For example, the image shows an inkjet printer, an output device that can make a hard copy of any information shown on your monitor.

MONITORMonitors, commonly called as Visual Display Unit (VDU), are the main output device of a computer. It forms images from tiny dots, called pixels that are arranged in a rectangular form. The sharpness of the image depends upon the number of pixels.

TYPES OF MONITORS

CRT (CATHODE RAY TUBE)

LCD (LIQUID CRYSTAL DISPLAY)

LED (LIGHT EMITTING DIODE)

Cathode-Ray Tube (CRT) The CRT display is made up of small picture elements called pixels. The smaller the pixels, the better the image clarity, or resolution. It takes more than one illuminated pixel to form whole character, such as the letter ‘e’ in the word help.

LCD MONITOR

A liquid-crystal display (LCD) is a flat-panel display or other electronic visual display that uses the light-modulating properties of liquid crystals. Liquid crystals do not emit light directly. LCDs are available to display arbitrary images (as in a general-purpose computer display) or fixed images with low information content, which can be displayed or hidden, such as preset words, digits, and 7-segment displays, as in a digital clock. They use the same basic technology, except that arbitrary images are made up of a large number of small pixels, while other displays have larger elements.

LED MONITORAn LED display is a flat panel display, which uses an array of light-emitting diodes as pixels for a video display. Their brightness allows them to be used outdoors in store signs and billboards, and in recent years they have also become commonly used in destination signs on public transport vehicles. LED displays are capable of providing general illumination in addition to visual display, as when used for stage lighting or other decorative (as opposed to informational) purposes.

GRAPHIC PLOTTERThe plotter is a computer printer for printing vector graphics. In the past, plotters were used in applications such as computer-aided design, though they have generally been replaced with wide-format conventional printers. A plotter gives a hard copy of the output. It draws pictures on a paper using a pen.

TYPES OF PLOTTERSDrum Plotters

Flatbed Plotters

DRUM PLOTTERSA drum plotter is also known as Roller Plotter. It consists of a drum or roller on which a paper is placed and the drum rotates back and forth to produce the graph on the paper. It also consists of mechanical device known as Robotic Drawing Arm that holds a set of colored ink pens or pencils.

Use in blue prints (CAD)

FLATBED PLOTTERSA flatbed plotter is also known as Table Plotter. It plots on paper that is spread and fixed over a rectangular flatbed table. The flatbed plotter uses two robotic drawing arms, each of which holds a set of colored ink pens or pencils. The drawing arms move over the stationary paper and draw the graph on the paper.

PRINTER

Printer is an output device, which is used to print information on paper.

TYPES OF PRINTERS IMPACT PRINTERS

NONE IMPACT PRINTERS

IMPACT PRINTERS

The impact printers print the characters by striking them on the ribbon which is then pressed on the paper.Characteristics of Impact Printers are the following:• Very low consumable costs• Very noisy• Useful for bulk printing due to low cost• There is physical contact with the paper to

produce an image

TWO TYPES OFIMPACT PRINTERS

CHARACTER PRINTERS

LINE PRINTERS

CHARACTER PRINTERSDOT MATRIX PRINTERIn the market one of the most popular printers is Dot Matrix Printer. These printers are popular because of their ease of printing and economical price. Each character printed is in form of pattern of dots and head consists of a Matrix of Pins of size (5’7, 7’9, 9’7 or 9’9) which come out to form a character that is why it is called Dot Matrix Printer.

DAISY WHEELHead is lying on a wheel and pins corresponding to characters are like petals of Daisy (flower name) that is why it is called Daisy Wheel Printer. These printers are generally used for word-processing in offices which require a few letters to be sent here and there with very nice quality. It is like a typewriter.

LINE PRINTERSLine printers are the printers which print one line at a time.

DRUM PRINTERThis printer is like a drum in shape so it is called drum printer. The surface of drum is divided into number of tracks. Total tracks are equal to size of paper i.e. for a paper width of 132 characters, drum will have 132 tracks. A character set is embossed on track. The different character sets available in the market are 48 character set, 64 and 96 characters set. One rotation of drum prints one line. Drum printers are fast in speed and can print 300 to 2000 lines per minute.

CHAIN PRINTERIn this printer, chain of character sets are used so it is called Chain Printer. A standard character set may have 48, 64, or 96 characters.

NONE IMPACT PRINTERS

Non-impact printers print the characters without using ribbon. These printers print a complete page at a time so they are also called as Page Printers.

Characteristics of Non-impact Printers Faster than impact printers. They are not noisy. High quality. Support many fonts and different character size.

These non-impact printers are oftwo types:

Laser Printers

Inkjet Printers

Laser PrintersThese are non-impact page printers. They use laser lights to produce the dots needed to form the characters to be printed on a page.

ADVANTAGESVery high speedVery high quality outputGive good graphics qualitySupport many fonts and different character size

DISADVANTAGESExpensive.Cannot be used to produce multiple copies of a document in a single printing.

Inkjet Printers

Inkjet printers are non-impact character printers based on a relatively new technology. They print characters by spraying small drops of ink onto paper. Inkjet printers produce high quality output with presentable features.

They make less noise because no hammering is done and these have many styles of printing modes available. Colour printing is also possible. Some models of Inkjet printers can produce multiple copies of printing also.

ADVANTAGESHigh quality printingMore reliable

DISADVANTAGESExpensive as cost per page is highSlow as compared to laser printer

PROJECTOR

PROJECTORA projector or image projector is an optical device that projects an image (or moving images) onto a surface, commonly a projection screen.

Most projectors create an image by shining a light through a small transparent lens, but some newer types of projectors can project the image directly, by using lasers. A virtual retinal display, or retinal projector, is a projector that projects an image directly on the retina instead of using an external projection screen.

TYPES OF PROJECTORS CRT PROJECTOR DLP PROJECTOR VIDEO PROJECTOR LCD PROJECTOR LED PROJECTOR LCoS PROJECTOR

CRT PROJECTOR

A CRT projector is a video projector that uses a small, high-brightness cathode ray tube as the image generating element. The image is then focused and enlarged onto a screen using a lens kept in front of the CRT face. The first color CRT projectors came out in the early 1950s. Most modern CRT projectors are color and have three separate CRTs (instead of a single, color CRT), and their own lenses to achieve color images.

DLP PROJECTOR

Digital Light Processing (DLP) is a display device based on optical micro-electro-mechanical technology that uses a digital micromirror device. DLP is used in a variety of display applications from traditional static displays to interactive displays and also non-traditional embedded applications including medical, security, and industrial uses.

VIDEO PROJECTORA video projector is an image projector that receives a video signal and projects the corresponding image on a projection screen using a lens system. All video projectors use a very bright light to project the image, and most modern ones can correct any curves, blurriness, and other inconsistencies through manual settings. Video projectors are widely used for many applications such as conference room presentations, classroom training, home theatre and concerts. Projectors are widely used in many schools and other educational settings.

LCD PROJECTOR

An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface. It is a modern equivalent of the slide projector or overhead projector. To display images, LCD (liquid-crystal display) projectors typically send light from a metal-halide lamp through a prism or series of dichroic filters that separates light to three polysilicon panels – one each for the red, green and blue components of the video signal. As polarized light passes through the panels (combination of polarizer, LCD panel and analyzer), individual pixels can be opened to allow light to pass or closed to block the light. The combination of open and closed pixels can produce a wide range of colors and shades in the projected image.

LED PROJECTORA TV projector that uses LEDs for its light source. See data projector and front-projection TV.

LED projectors are becoming more and more popular. LED technology is being used in a wide range of products, including home theater projectors, business and education projectors, and even the emerging market of Pico projectors, and other mini projector systems. This has its benefits in a variety of fields, with several different uses.

SPEAKERS

Computer speakerAlso known as multimedia speakers, are speakers sold for use with computers, although usually capable of other audio uses, e.g. for an MP3 player.

Types of Speakers

TWO-SPEAKER SYSTEM 2.1 SPEAKER

5.1 SPEAKER

7.1 SPEAKER

Wireless SPEAKER

HEADPHONES

Headphones are a pair of small listening devices that are designed to be worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound in the user's ear. Headphones are designed to allow a single user to listen to an audio source privately, in contrast to a loudspeaker, which emits sound into the open air, for anyone nearby to hear. Headphones are also known as earspeakers, earphones or, colloquially, cans. Circumaural and supra-aural headphones use a band over the top of the head to hold the speakers in place.

Types of Headphones

CLIP-ON HEADPHONESBEHIND THE NECK HEADPHONESNOISE CANCELLING HEADPHONESHEADPHONES WITH MICROPHONE

NOISE CANCELLING HEADPHONES

These types of headphones excel in cancelling external noise to a greater extent. Almost by 90%!They are designed in such a way that…...ambient noise gets reduced by a larger margin when you wear them on.

Noise Cancelling Headphones are of two types

ACTIVE NOISE CANCELLING

PASSIVE NOISE CANCELLING

Softwarea generic term for organized collections of computer data and instructions, often broken into two major categories:

1. System Software that provides the basic non-task-specific functions of the computer.

2. Application Software which is used by users to accomplish specific tasks.

System Software1) Microsoft Windows 2) Linux 3) Unix 4) Mac OSX 5) DOS 6) BIOS Software 7) HD Sector Boot Software 8) Device Driver Software i.e Graphics Driver etc 9) Linker Software 10) Assembler and Compiler Software 

Application Software

Examples : Web browser, word processing software, spreadsheet software, database software, presentation graphics software. 

1) Opera (Web Browser) 2) Microsoft Word (Word Processing) 3) Microsoft Excel (Spreadsheet software)4) AutoCAD 2007 (Engineering Software)5) MySQL (Database Software) 6) Microsoft Powerpoint (Presentation Software) 7) iTunes (Music / Sound Software) 8) VLC Media Player (Audio / Video Software ) 9) World of Warcraft (Game Software) 10) Adobe Photoshop (Graphics Software)

FirmwareA program that's written to the read-only memory (ROM) of a computing device.  Also known as embedded software and example of this is microcontroller.

Arduino Microcontroller

Quiz1. Define Computer (3 points)2. Give 1 characteristic of Computer (2points)3. Give the 3 parts of Computer (3 points)4. Give 3 Hardware of Computer (3 points)5. Give 2 Input Device (2 points)6. Give 2 Output Device (2points)7. Give the 2 types of Software (2 points)8. Give 3 examples of Application Software (3

points)