Input and Output Devices of Computer

 INPUT DEVICES:

The elements of a computer which can enter data into the computer are called Input Devices.

Types of Input Devices:

1.      Keyboard

2.      Mouse

3.      Track ball

4.      Light pen

5.      Joy stick

6.      Magnetic Ink Readers(MIR)

7.      Optical Character Readers (OCR)

8.      Scanners

9.      Voice Synthesizer

10. Barcode Reader

Q: Describe Keyboard and its division? (2002 Q2-c)

KEYBOARD

            Keyboard is a device which is used to feed data into computer. It is like a type writer. Following are the division of keyboard.

1.      Alphanumeric keypad

2.      Numeric keypad

3.      Functions keypad

4.      Special function keypad

1. Alphanumeric Keypad:

            It contains all alphabets a-z, A to Z, numbers 0- 9 and some special characters e.g, @ , # , $ , % , ^  etc.

2. Numeric Keypad:

It is located on the right side of keyboard containing numbers 0- 9 , arithmetic notations, (+ , - , *, /) and some special function keys.

3. Functions keypad:

            It is a set of twelve keys from F1 to F12 located at the top of keyboard. All of these keys have predefined instructions which are different for different software.

4. Special Function Keypad:

            Besides all above mentioned keys some more keys can be seen on the keyboard. Enter, Shift, Scroll etc. These keys are known as special function keys which are spread on the keyboard at different locations.

MOUSE(2002 Q2-c):

             Mouse is an input device also called pointing device. It is a common pointing device that senses its movement across a flat surface and transmits that information to the computer, typically to control the position of a cursor or pointer. A mouse is usually equipped with 1-3 buttons that also send signals to the computer. The wire connecting it to the computer or keyboard looks like a mouse's tail. A mouse is moved over a flat horizontal surface, usually a rubber mouse pad, and its position is read by the computer. The mouse is easier and faster to use than the keys on the keyboard.

OUTPUT DEVICES:

Output devices are those which convert computer signals into a form to be understood by user.

Some commonly used output devices are as follows:

1.      Monitors

2.      Printers

3.      Plotters

4.      Computer output on microfilm (COM)

|  MONITORS:

It is a device similar to a television screen that receives video signals from the computer and displays the information for the user.

OR

It is a peripheral device with a screen for the visual display of information.

TYPES OF MONITOR:

a.      Monochrome Monitor

b.      Color Monitor

a.      MONOCHROME MONITOR:

Monochrome monitor can display shades of one color. They are less expensive than those with color.

b.      COLOR MONITOR:

There are two types of color Monitor:

1. RGB Monitor:

Most color monitors mix red, green, blue colors to achieve a spectrum of colors and are called RGB Monitor.

2. Composite Monitor:

The composite monitor is set up to display up to 256 colors. It works as the same way as color TV set.

CRT MONITORS:

            CRT stands for cathod ray tube. CRT monitor uses a technology called raster scanning, a process of sweeping electrons beams across the back of the screen. The backing the screen is coated with phosphorous that glows whenever it is hit by a beam of electrons.

|  PRINTERS:

A computer printer is a computer peripheral device that produces a hard copy (permanent human-readable text and/or graphics, usually on paper) from data stored in a computer connected to it.

            OR

Printer is a device that translates signals from a computer into words and images onto paper in black and white or color. Printer types include dot matrix, ink jet, laser, impact, fax, and pen and ink devices.

Printers are divided into two types:

a.      Impact Printers

b.      Non Impact Printers

1)       IMPACT PRINTERS:

a.      Character Printer:

They print single character at a time. E.g Dot matrix, Daisy wheel printer

b.      Line Printer:

They print a full line at a time. e.g Drum printer

c.      Non Impact Printers:

1.      Thermal Printer

2.      Ink Jet Printer

3.      Laser Printer etc

Q: Explain the function of arithmetic logic unit in computer.

(2003 Q5-a)

             

ARITHMETIC AND LOGIC UNIT:

Arithmetic and Logic Unit is a part of the CPU that performs arithmetical and logical operations on data. Arithmetic and Logic Unit Carries out additions, subtractions, multiplications and divisions, as well as logical operations ( &, | , ! ). An arithmetic logic unit (ALU) is a core component of all computer CPUs. ALUs are capable of calculating the results of a wide variety of basic arithmetical computations, most commonly the following ones:

a.      integer arithmetic operations (addition, subtraction, multiplication)

b.      bitwise logic operations (AND, NOT, OR, XOR)

c.      bit-shifting operations (shifting or rotating a word by a specified number of bits to the left or right, with or without sign extension)

Q: How many types of busses are there in a computer? Explain the function of each bus. ( 2003 Q5-b)

A collection of wires through which data is transmitted from one part of a computer to another. When used in reference to personal computers, the term bus usually refers to internal bus. This is a bus that connects all the internal computer components to the CPU and main memory.

All buses consist of two parts:

1. Address Bus: the address bus transfers information about where the data should go.

2. Data Bus: The data bus transfers actual data.

3. Control Bus: the control bus carries commands from the CPU and returns status signals from the devices.

Q: Difference between Dot Matrix printer and Daisy wheel Printer.

DOT MATRIX PRINTER	DAISY WHEEL PRINTER
1. Dot matrix can print many type of character in one document.	Daisy wheel printer can print only in one style of character.
2. It can print at a speed of 30 to 600 cps.	It can print at a speed of 10 to 90 cps.
3.They are faster than daisy wheel.	They are slower.
4.They have only one head to print a complete line character wise.	They have a wheel to print on which characters are embossed on each petal of wheel.
5.Dot matrix printer can also print pictures, drawing and graphic.	Daisy wheel printer cannot print picture, drawing and graphics.
6.The head has pin like hammer, which strikes the ribbon to print character in dotted form.	Hammers strike the ribbon to produce character on the paper.

Q: Difference between softcopy and hard copy:

SOFTCOPY	HARDCOPY
1. A compute output displayed on monitor is called softcopy.	A computer output taken on a paper is called as hardcopy.
2.Soft copy is temporary.	Hard copy is permanent.
3.Device used for getting soft copy is monitor.	Device used for getting hard copy are printers and plotters.

FILL IN THE BLANKS

1.      Computer is a machine that accepts input data, processes and gives Out put.

2.      CPU consists of four main parts.

3.      The CU, ALU and registers are combined in a single chip called Microprocessor.

4.      Memory units is divided into RAM and ROM

5.      RAM is a volatile memory.

6.      ROM  is a non volatile memory.

7.      PROM stands for  Programmable Read Only memory.

8.      EPROM stands for Erasable Programmable Read Only Memory.

9.      EPROM stands for  Electrically Erasable Programmable Read Only Memory.

10.    EDP stands for Electronic Data Processing.

11.    ROM stands for Read Only Memory.

12.    RAM stands for Random Access Memory.

13.    Keyboard, Mouse Track Ball are Input device.

14.    Keyboard, is divided into Four keypads.

15.    Joystick is used to play game.

16.    Mouse is a pointing device.

17.    CRT stands for Cathode Ray Tube.

18.    VDT stands for Video Display Terminal.

19.    LCD  stands for Liquid Crystal Display.

20.    LASER stands for Light Amplification by Stimulated Emission of Rays.

21.    Printers are divided into tow types Impact and non-impact printers.

22.    Impact printer can produce carbon copy.

23.    Floppy disk and hard disk are magnetic disk.

24.    A computer output taken on a paper is called hard copy.

25.    A hard copy output taken on paper by printer or plotter.

26.    Data fed into the computer is called input.

27.    Photo electric device to read the codes by means of reflected light is said to be barcode reader.

28.    Monitor gives soft copy of information.

29.    Registers are temporary special storage areas built into microprocessor.

29.    In RAM data is stored temporarily.

30.    In ROM  data is stored permanently.

31.    Cache memory is high speed solid state memory for program instruction.

31.    EDP stands for Electric Data Processing.

32.    CD-ROM stands for Compact Disk Read Only Memory.

33.    The primary advantage of optical disk technology is high capacity of storing data.

34.    A million of a second is called microsecond.

35.    The Unit that consists of both the control unit and arithmetic logic unit is CPU.

36.    Five other names for memory are:

(a)     Main storage  (b)            internal storage            (c)        Primary storage

(d)     Primary memory            (e)        main memory.

37.    MIPS stand for Million Instructions Per Second.

38.    The main circuit board is called mother board.

39.    Type of chip that holds programs that will not be altered is called ROM.

40.    Instruction time is called I-time.

41.    Executive time is called E-time.

42.    A machine cycle is the combination of I-time and E-time.

43.    CD-ROM and DVD-ROM are optical disks.

FILL IN THE BLANKS

(1)     Computer network is a system composed of two or more computer or terminals.

(2)     In hierarchical topology the computer at the highest order of the hierarchy controls all traffic between the end users.

(3)     In a bus topology a signal is broadest to all nodes.

(4)     A ring network links all nodes together in a circular chain.

(5)     LAN is a network in which the computers are close to each other.

(6)     All Computers Peer to Peer arrangement have equal status.

(7)     Simplex transmission sends data in one direction only.

(8)     Full duplex transmission allows transmission in both directions at once.

(9)     Fiber optics are made up of glass fibers.

(10)   GAN stands for Global Area Network.

(11)   MAN stands for Metropolitan Area Network. 

(12)   Internet is a public communication world wide network.

(13)   A modem is a device that converts digital signals into analog signals and vice verse.

(14)   Changing a signal from analog to digital signals is called modulation.

(15)   Changing a signal from analog to digital is called demodulation

(16)   Router is a special computer that directs communication traffic when several networks are connected together.

(17)   E-mail stands for Electronic Mail.

(18)   The protocol that makes remote login possible is called Telnet.

(19)   FTP stands for File Transfer Protocol.

(20)   Web pages are often written in Hyper Text Markup language (HTML).

(21)      ISP stands for Internet Service Provider.

(22)   Antivirus is a computer program that stops the spread of a virus.

(23)   NIC stands for Network Interface Card.

(24)   Personal computers and other hardware attached to a LAN are called nodes.

MULTIPLE CHOICES:

1.             One or more computers connected to a hub computer is a (n)

         (a) ring network         (b) star network   (c)  bus         

2.      The Physical layout of a LAN:

         (a)    topology            (b) connection      (c) link

3.      A network that places all nodes on a single cable:

         (a)    bus                     (b) Car                 (c) ring

4.      Microwave transmission, coaxial cables, and fiber optics are example of:    

         (a)     modems            (b) communication links        (c) ring network

TRUE FALSE:

1.   Local Area Networks are designed to share data and resources among

      several computers in the same geographical location.                  T/F

2.   Full duplex transmission allows transmission in both directions

      at once.                                                                                         T/F.

3.   Another name for file server is peer to peer.                                T/F.

4.   A ring network has no central host computer.                              T/F.

5.   A bus network uses a central computer as the server                   T/F.

6.   Two dissimilar network can be connected by getaway.               T/F.

7.   LAN is a network of geographically distant computer

      and terminals.                                                                               T/F.

Input and Output Devices of Computer