Information about Computer I/O Devices

Fast Fact:
Devices, like USB drives, CD-ROMs, modems, and network cards are the ones that possess the properties of accepting input as well as transferring output.
The computer is no more a luxury, but a necessity in the 21st century. In fact, science has expanded its horizons to such an extent that the desktop computer could be added amongst the list of outdated technology!! Today, operating systems and software configurations are available on smartphones and tablets, while LED monitor screens, laptops, and better microprocessor technology has replaced the desktop computer. Despite the improvement, one still requires input and output devices to communicate with this machine. The article below explains the use and functionality of these devices in detail.

An Introduction

I/O is a collection of interfaces that different units of an operational processing system used to communicate to each other.
Inputs are the signals received by those units, while outputs are the sent signals.
I/O devices are used by people or by other systems to communicate with the computer.
Usually, these outputs are called ‘results’ and they can be addressed to people or can be used for guiding some other machines and robots.
For instance, in the industrial robot’s case, the most important output device is the one that sends all the detailed signals about the mechanical signals to the robot – signals which the robot understands and moves according to them.
The first generation of computers were equipped with a limited range of i/o devices; reading data and instructions was possible with a perforated card reader or something similar, and for showing the results a printer was used, usually a teleprinter (teletypewriter, teletype or TTY for TeleTYpe/TeleTYpewriter).
The modern teletypewriters are used by deaf for typed communication over a telephone.
Technically, i/o devices are the ones that are bi-directional, i.e., they can function as input as well as output devices.
They are mostly referred to as storage or communications devices.
In general though, the term ‘i/o’ refers to input as well as output devices and those that can perform the functionality of both input and output.

Input Devices

The Keyboard

The keyboard is a vital input device with the help of which we can enter text, symbols, codes, alphanumeric characters, etc., on the screen.
The system has a built-in virtual keyboard, but it is highly irritating to use the mouse buttons to input data through this keyboard.
There are innumerable shortcuts to various functions that can be achieved via the keyboard.
Prior to its invention, typewriters, and punch cards were in vogue; following their decline, the keyboard became the most vital input device.
Laptops and notebooks have an attached keyboard – it is a part of the piece.
Smartphones and tablets come with virtual keyboards of course – with the same pattern as that of the actual keyboard, and are operated exactly the same way how we operate regular keyboards. They are called thumb-sized keyboards.
This device consists of the alphabets arranged in the center, with the spacebar key.
The numerical bar along with special characters is arranged above this section, and above this, you will find the function keys ranging from F1 to F12.
With rapidly advanced technology, keyboards are likely to undergo further change and be made more user-friendly and quick.

The Mouse

Mouse device

The mouse is a small, haphazardly oval-shaped device with two or three buttons, which are clicked to input data on to the screen.
Nowadays, the device has two buttons only, one on the left and one on the right, and a scroll roller in between, to scroll up and down the screen.
The underside of this device consists of a small roller ball with the help of which the user is able to roll the mouse on the mouse pad (if you turnover the mouse, you will see the ball rotating beneath a small hole).
This device is used for clicking the options you require from a list of selected options.
It is used in 3D graphics as well, to orient the figure as per the user’s dimensions and requirements.

Other Composite Devices

Other input devices include options, like the joystick, scanner, etc.
The joystick is a device that is generally used to play games.
You may have also hear of the game controller or the wii remote – both are used for gaming purposes.
Initially, the joystick was more like a mike-shaped knob over a rectangular box attached to a movable level. The design has considerably changed since then.
The scanner is a device that is used to scan hard copies and convert the same to an image format on the computer.
There are several other input devices used for imaging purposes – the digital camera, media player, fingerprint scanner, webcam, etc.

Output Devices

The Monitor

The monitor is one of the most important output devices – it is where one views the output.
The initial monitors were called CRTs (Cathode Ray Tubes) that had quite a few limitations as compared to the modern ones we have today.
The LCDs (Liquid Crystal Displays) arrived next. They were lightweight, clear, easy-to-use, and consumed lesser power.
As of today, one prefers using the LED (Light Emitting Diode) monitors that are based on very advanced technology, though they use considerably higher power and are expensive.
Laptops, palmtops, tablets, smartphones, etc., obviously do not need the monitor, the screen serves as the output device, and has a high resolution.

The Printer

The printer, as the name suggests, is used to print hard copies of various documents, images, etc.
There are various types of printers – one of the earliest ones used was the dot matrix and the daisy wheel printer, which is obsolete as of today.
The dot matrix used a small pin matrix to get ink printed on the paper.
Next, we had the typewriter-based and solid ink printers.
Today, we have laser printers, that have the best functionality, design, and output quality.

The Sound System

The sound system of the computer involves the devices related to the audio.
The sound devices primarily include the speaker system, headphones, etc.
Initially, the speakers that came along with the computer system were humongous and had sound-adjusting buttons right on the device.
The design and functionality of the speakers have vastly improved since then.
Laptops have speakers installed right on the console.
The sound can be adjusted from the options available on the computer, in the ‘Control Panel’ section.
The headphones are used to hear sound without disturbing others around.

I/O Devices

CD-ROM Drives

CD-ROM devices function as input as well as output devices.
It is a compact disc, and is used to store important information – documents, songs, images, movies, etc.
CD-ROM stands for ‘Compact Disc – Read Only Memory’. This is an important point you need to remember. These CDs are readable only – the computer can read data from them, but you cannot copy the data.
For this purpose, you need to use a re-writable CD-ROM. Using this, you can read data into the computer, copy or transfer data from the PC to the CD, even erase the data and store/replace with new data, which is not possible on a ‘Read only’ device.

USB Flash drives

The USB flash drive is a small device with considerable storage space, ranging from 1 GB to 8GB.
Using this flash drive, you can directly transfer data to and from the computer.
You can use the USB on various computers and laptops, thus enabling information transfer from one computer to another.
In fact, off late, bluetooth technology has made it possible to have wireless transfer of data within a specific range.
Prior to the invention of the USB, floppy disks were in great demand; as of now though, no CPUs are even manufactured with floppy disk drives.

Hard Disk Drives

A hard disk is typically stored inside the processor.
Your hard disk is where all your data is stored – it is the memory section of the computer.
Sometimes, we have so much of data to be stored and worked upon, that the computer/laptop memory proves insufficient.
Often, excess data storage may cause the machine to hang or crash altogether. This problem is solved using an external hard disk.
This device is like a heavy rectangular box with an attached cable for inserting in the other machine.
It contains extensive storage memory – you can store a huge amount of data.
It facilitates easy transfer of information from one computer to another without having to resort to means like formatting the machine due to excess data usage, etc.

When the perspective changes, the designations of the input/ output devices change as well. The physical movement we as humans do on the mouse or keyboards is perceived as an output by the computer, and it is transformed in specific language/signals that the computer deciphers. Therefore, the output from a mouse or from the keyboard is perceived as input by the computer. When it comes to the printer or a monitor, these devices receive the input what the computer sends as output, which is afterwards translated into a language the human factor can understand. Once more, a person takes as input the output of the computer, namely, the directions on the screen. Thus, each transfer represents an output from a certain device and an input into a different one.