Input and Output Devices of Computer

Input Devices:

In computing, an input device is a piece of computer hardware equipment used to provide data and control signals to an information processing system such as a computer or information appliance. Examples of input devices include keyboards, mouse, scanners, digital cameras and joysticks. Audio input devices may be used for purposes including speech recognition.

• Keyboards:

 'Keyboards' are a human interface device which is represented as a layout of buttons.

• Mouse:

Pointing devices are the most commonly used input devices today. A pointing device is any human interface device that allows a user to input spatial data to a computer. 

• Video Input Devices:

 Video input devices are used to digitize images or video from the outside world into the computer. The information can be stored in a multitude of formats depending on the user's requirement.

   Examples of types of a video input devices include:

•     ·         Digital camera
•     ·         Digital camcorder
•     ·         Portable media player
•     ·         Webcam
•     ·         Microsoft Kinect Sensor
•     ·         Image scanner
•     ·         Fingerprint scanner
•     ·         Barcode reader
•     ·         3D scanner
•     ·         Laser rangefinder
•     ·         Eye gaze tracker
•     ·         Computed tomography
•     ·         Magnetic resonance imaging
•     ·         Positron emission tomography
•     ·         Medical ultrasonography

• Audio Devices:

Audio input devices are used to capture sound. In some cases, an audio output device can be used as an input device, in order to capture produced sound. Audio input devices allow a user to send audio signals to a computer for processing, recording, or carrying out commands. Devices such as microphones allow users to speak to the computer in order to record a voice message or navigate software. Aside from recording, audio input devices are also used with speech recognition software.

Examples of types of audio input devices include:

•   Microphones
•   MIDI keyboard or other digital musical instrument

• Others:

•  Gesture recognition
•  Digital pen
•   Magnetic ink character recognition
•  Sip-and-puff#Computer input device 

 

Output devices:

An output device is any piece of computer hardware equipment which converts the electronically generated information into human-readable form.

In brief, output unit is responsible for providing the output in user readable form. It can be text, graphics, tactile, audio, and video.

Some of the Output devices are Visual Display Units (VDU) i.e. a Monitor, Printer, Graphic Output devices, Plotters, Speakers etc. A new type of Output device is been developed these days, known as 

Speech synthesizer, a mechanism attached to the computer which produces verbal output sounding almost like human speeches.

Display devices:

Since the beginning of the computer history & evolution we always have seen a sort of display device on the computer. A display device is the most common form of output device. It presents output visually on computer screen. The output appears temporarily on the screen and can easily altered or erased, it is sometimes referred to as soft copy also. The display device for a desktop PC is called Monitor.

With all-in-one PCs, notebook computers, hand held PCs and other devices; the term display screen is used for the display device. The display devices are also used in home entertainment systems, mobile systems, cameras and video games.

Display devices form images by lighting up the proper configurations of pixels. In short the display devices are organized in the form of Pixels, & pixels are arranged in the form of Matrix, a 2-dimensional matrix which is organized as rows & columns.

How Does a Computer Process Data?

Before data is processed by a computer, it has to be fed into the computer using a keyboard, mouse or another input device. The central processing unit (CPU) analyzes the raw data and processes it into sensible information. The CPU receives instructions from the user and issues prompts accordingly. After the data is processed, it is translated to output formats that are easily understandable by the user.

The processed data is displayed on the computer for editing, viewing or playing. The computer’s CPU then receives instructions from the user to save the data securely on the hard drive. Later, the user can choose to modify, copy, move, edit or delete the data. Some of the output values that data is converted into are documents, video files and audio files.

A computer system is comprised of three main parts: hardware, software and users. All components connected to the computer via cable or wireless access point are hardware. These are primarily the tangible parts that include the CPU, monitor, keyboard and mouse. In addition, machines such as printers and scanners are considered part of the computer's hardware. Software consists of the computer applications installed on the computer and used to execute functions. Users are the people who provide instructions to the computer.

Different Types of Computers Around the World:

There are Four Different Computer Types

We have four different computer types classified according to their performance, power, and size. A computer is an electronic device that accepts data, processes it, stores, and then produces an output.

There are different computer types available depending on the number of users they can support at any one time, their size, and power. In this hub, we are going to have a look at the difference

between supercomputers, mainframe, mini, and microcomputers. 

Supercomputers

 Supercomputers are Very Fast and Most Powerful

1. Supercomputers – Supercomputers are very expensive, very fast, and the most powerful computers we have in the world.

Supercomputers are optimized to execute a few numbers of programs. This makes it possible for them to execute these few programs at a very high speed. Due to their inhibiting cost, they are used in high end places like in scientific research centers. The supercomputer consists of thousands of processors making it clock very high speeds measured by petaflops.

These computer types are also very large in size due to the numerous parts and components involved in their design.

A good example of a Supercomputer is Tianhe-2: TH-IVB-FEP Cluster; National Super Computer Center in Guangzhou, China; 3.1

Mainframe Computers

 

2. Mainframe computers — These are large and expensive computer types capable of supporting hundreds, or even thousands, of users simultaneously. Thus, they are mostly used by governments and large organizations for bulk data processing, critical applications, transaction processing, census, industry and consumer statistics among others. They are ranked below supercomputers.

                     

Minicomputers

3. Minicomputers — Minicomputers are mid-sized computers. In terms of size and power, minicomputers are ranked below mainframes. A minicomputer is a multiprocessing system capable of supporting from 4 to about 200 users simultaneously.

Microcomputers

4. Microcomputers or Personal computers – A personal computer is a computer designed to be used by one user at a time. The term microcomputer relates to microprocessor which is used with a personal computer for the purpose of processing data and instruction codes. These are the most common computer types since they are not very expensive.

  Microcomputers Are Classified as Desktop and Portable (Mobile) Computers

Desktop Computers

Desktop computers are not built to be mobile. They are moved, but only to a new desktop location and with the power supply inactive. There are a number of major differences between computers that are intended to be used in one place as a desktop and portables or mobiles that can be easily moved from one location to another.

Desktop computers are large and heavy in comparison to portables. They can be carried in specially manufactured cases, but only to assist a support engineer in moving, not as a frequent procedure. The monitor, keyboard and mouse are all separate items on a desktop.

Desktop computer components and devices, although quite resilient to movement while active are not made to be constantly moved, even less so when they are operational. A mains power supply is mandatory, as desktop computers cannot work without a constant supply of electrical power.

The desktops can further be subdivided depending with the casing type, tower casing and desktop casing.

Tower casing

For tower casing, the motherboard is placed on side of the system unit, while the other major components like the power supply, and mass storage devices are stacked on top of each other in a cabinet. One main advantage with computers using the tower casings is that there is ample space for future upgrades for example if you wish to add more storage devices. 

A Mid Tower Case

Desktop casing

For the desktop casings, the motherboard lies on the bottom and is parallel to the desk or table. The system unit is usually smaller and more compact. It is not a very good choice if you are going to install other drives like another hard disk or a DVD writer. One main advantage is that they are small and thus will occupy less space. The placement is also ideal since it will lie on top of a desk and then you can place your TFT monitor on top.

Tower or Desktop Computer?

Note: You can flip over the tower casing and end up with a desktop and you can turn your desktop to a tower literally though but the problem will be your drives will be facing sideways. So you will always have a problem inserting or removing your CDs because they will keep on falling, other drives might fail to access your CD or DVD contents due to the awkward tilted position.

Why choose a desktop?

The size of the casing determines how much space you need on your desk to place the PC. If you have a small desk with limited space, you might consider the smaller minicomputer case.

There are two things that may make you consider going for tower:

a) If you have more than enough space is not an issue, then you can go for the tower casing where there are more functions.

b) If you will be adding a lot of devices to your system, for example more drives.

In terms of cost, tower casings prices are a little bit higher compared to desktops.

Portable or Mobile Computers

Portable or mobile computers are manufactured with a very important feature; they are portable (are designed for mobility). This means a computer user can be able to move with it from one point to another comfortably. One can also work from any location irrespective of if there is a power source. They:

• Are small, compact and light in weight
• Have their own power in form of a battery but of course it does not last forever, thus they have to be plugged to a source of power once in a while.

These portable devices are produced in a variety of sizes and very high processing capabilities. Good examples are Laptops, Palmtops, and PDAs.

An Example of the Portable Computers