3rd Class Computers Science Input and Output Devices Input / Output Devices

       Input /Output Devices  

In computing Input / Output or I/O refers to the communication between an information processing system (such as a computer) and the outside world. Inputs are the signals or data sent to the system and outputs are the signals or data sent by the system to the outside. Input/ Output devices are hardware devices that accept inputted information and also have the capability of outputting that information. Good examples of an Input/ Output device are a floppy diskette drive, CD-ROM and DVD-ROM units and a hard while some devices are considered only Input or Output devices, the typical devices for communication between computers are considered to be both Input and Output. For instance, the modem lets you connect to another computer, while allowing you to send and receive data and information at the same time. Another typical example is the network card that basically does the same thing in a small network. These kinds of devices are termed as bidirectional. Let's learn about some I/O devices in detail.   

     Floppy Disk  

A floppy disk is a data storage medium that is composed of a disk of thin, flexible, magnetic storage medium encased in a square or rectangular plastic shell. Floppy disks are read and written by a floppy disk drive or FDD. They were invented by the American information technology company IBM. Floppy disks come in different sizes - in 8-inch (203 mm), 5+1D 4 in (133 mm) and 3+1D 2 in (89 mm) formats. For nearly three decades from the mid-1970s to the late 1990s, floppy disks were a popular form of data storage and exchange. While floppy disk drives still have some limited uses, they have now been replaced by USB flash drives, external hard disk drives, CDs, DVDs and memory cards.  

     CD-ROM

You must have seen or used CDs for matching movies, playing games and listening to music. CD-ROM is an acronym of "Compact Disc Read-Only Memory". It is a type of optical disk capable of storing large amounts of data ? up to 1GB, although the most common size is 650MB (Megabytes). A single CD-ROM has the storage capacity of 700 floppy disks and enough memory to store about 300,000 text pages. It is a pre-pressed compact disc for data storage and music playback. CD-ROMs are stamped by the vendor and once stamped; they cannot be erased and filled with new data. To read a CD, you need a CD-ROM player. CD-ROMs are particularly well-suited for information that requires large storage capacity. This includes large software applications that support colour, graphics, sound and especially video. CD-ROMs are popularly used to distribute computer software, including games and multimedia applications, though any data can be stored (up to the capacity limit of a disc).  

     Touch Sensitive Monitor

From the ancient period, human beings have been exploring and manipulating objects with their hands to sense the size, shape, texture and mass, etc. A touch sensitive monitor is a pointing device that enables the user to interact with the computer by touching the screen. A touch screen is an electronic visual output that can detect the presence and location of a touch within the display area. The term generally refers to touch or contact to the display of the device by a finger or hand. Touch screens can also sense other passive objects, such as a pen.  

 Match the following          

              A                                                               B

1.  Floppy                                                    i. Electronic Visual Output

2. CD-ROM                                                 ii.  Plastic Shell

3.  Touch Sensitive Monitor                      iii. Read Memory

(A) 1, iii; 2, i; 3, ii                                               

(B) 1, ii; 2, iii; 3, i  

(C) 1, iii; 2, ii; 3, i                                              

(D) 1, i; 2, ii; 3, iii

(E) 1, ii; 2, i; 3, iii  

Answer: (B)

Explanation

Correct Option:

(B) Option (B) is matched correctly.

Incorrect Options:

(A) Option (A) is matched incorrectly.

(C) Option (C) is matched incorrectly.

(D) Option (D) is matched incorrectly.

(E) Option (E) is matched incorrectly.    

 Few statements are given below about Input/output devices. Select the correct statements.

1. In computing I/O refers to the communication between an information processing system and the outside world.

2. Input /Output devices are hardware devices that accept inputted information and also have the capability of outputting that information.

3. Floppy disks are read and written by a floppy disk drive or FDD.

(A) Only 1                                                           

(B) 1 and 2

(C) 2 and 3                                                          

(D) All of these

(E) None of these

Answer: (D)

Explanation

Correct Option:

(D) All the given statements are correct. Therefore, option (D) is correct.

Incorrect Options:

(A) Only statement 1 is not correct but 2 and 3 are also correct. Therefore, option (A) is incorrect.

(B) Not only statements 1 and 2 are correct but statement 3 is also correct. Therefore, option (B) is incorrect.

(C) Not only statements 2 and 3 are correct but statement 1 is also correct. Therefore, option (C) is incorrect.

(E) None of the given statements are incorrect. Therefore, option (E) is incorrect.  

• Input / Output devices are also known as peripherals since they surround the CPU and memory of a computer system.
• The world's first computer printer was a 19th century mechanically driven apparatus invented by Charles Babbage for his Difference Engine.
• Input devices other than the keyboard are sometimes called alternate input devices. Mice, trackballs and light pens are all alternate input devices.  

• CD ROM: A compact disc with one or more metal layers capable of storing digital information.  
• Dot Matrix printer: A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth or in an up and down motion, on the page and prints by impact.
• Floppy disks: A data storage medium that is composed of a disk of thin, flexible magnetic storage medium encased in a square or rectangular plastic shell.
• Joystick: A joystick is an input device consisting of a stick and is often used to control video games.
• Light Pen: An input device that utilizes a light-sensitive detector to select objects on a display screen.  
• Printer: A device which produces a hard copy (permanent readable text and/or graphics) of documents stored in electronic form, usually on physical print media such as paper.
• Trackball: A pointing device consisting of a ball similar to an upside-down mouse.
• Touch screen: A monitor which uses touching of the screen as an input method. Items can be selected or moved with a finger and finger gestures may be used to convey commands.

• Input and Output devices are the machines used with computer to complete a given task/job. With the help of these devices we can print, listen to music, play games, etc.
• Resources on Net:  http://www.wikipedia.org
• Related Topics : Introduction to Hardware and Software : Chapter 3
• Explore Keyboard : Chapter 5  

    Abbreviations

I/O                   -           Input and Output

VDU                 -           Video Display Unit

CPU                 -          Central Processing Unit

CD-ROM         -          Compact Disc Read-Only