I/O Devices

In this modern world, almost controlled by computers, people had to come up with a whole set of new words for everything our computers are made of. I bet it wasn’t that easy, but for sure it is very hard for the average user to have a clue as to what some of them mean.

This article tries to enlighten at least one, which is I/O. I/O is an abbreviation of INPUT and OUTPUT. 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 we call these outputs 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.

As time went by, the number of I/O devices has become greater and greater and of course, more sophisticated. For the computer today, the usually I/O devices are:

•Inputs: keyboard, mouse.
•Outputs: monitor, printer and the sound system.

Other devices are specialized only for some specific types of inputs or outputs, for instance the camera or the scanner.

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, just in a small network. These kinds of devices are termed as bidirectional.

There are some other types of I/O devices: the storage devices, like the hard-disk, the CD-ROM and DVD-ROM units – relatively slower devices, but with a larger storage capability, and the devices that help with connecting to computer networks.

It is important to notice that the previous designations of devices as either input or output change when the perspective changes. Mouses and keyboards take as input physical movement that the human user outputs and convert it into signals that a computer can understand. The output from these devices is treated as input by the computer. Similarly, printers and monitors take as input signals that a computer outputs. They then convert these signals into representations that human users can see or read. (For a human user the process of reading or seeing these representations is receiving input.)

Every input/output device transfers (in a way or another) data and information to the computer or receives information from the computer. Every transfer is an output from one device and an input into another.

The possibility to interconnect many computers for data transfer opened the path for a whole bunch of new applications. Internet, especially the WWW – World Wide Web – allows billions of computers from all around the world to connect and to transfer information of any kind. The internet network need Input and Output "devices", that means my computer, your computer and everybody’s computer. Being hooked up on internet makes you both input and output device. In all the time, you are sending information and receiving information; that’s how the internet works.

The future will bring us interesting gadgets and devices that will make our life easier. We already have lights that turn on or off only by clapping our hands. Some very high protected rooms have an eye scanner, or a hand scanner. I heard of cars that ask the owner to ‘say’ their name and password!! Are you ready to say "on" and the computer to turn on, or to say "email" and the computer to start reading your new mail?