The input devices are those that fulfill the function of entering or providing data and control signals to the central processing unit of a system. In most cases, we speak of input devices for devices that have a connection to the central unit of a computer, that is, the CPU. For example: mouse, scanner, webcam.
As stated, the central function of computers is the data processing, so it can be said that the very history of computation is the history of the improvement of processing methods:
Starting in 1970, in what is known as the fourth generation of computers, the most important innovation was the microprocessors (or chips), which generated a revolution in data processing matters: the processing speed rises to 770,000 instructions per second. The computer could be made much smaller, affordable for households, and much less expensive.
Since 1985, computer innovation has focused primarily on input via sound waves with wireless systems, as well as through the appearance of robotics: cybernetics advances faster and faster and the interconnections between computers demand the introduction of increasingly efficient methods for data entry and processing.
The fundamental division between the devices, then, is made according to their function with respect to processing:
- Input devices. They provide information to the computer for processing.
- Output devices. They are important for the reproduction and presentation of information to users.
However, there are some cases of mixed devices or hybrids, which at the same time send and receive signals to the different parts of the computer: the latest generation of devices such as the touch screen, the mouse or the scanner are examples of this.
Examples of input devices
- Optical pencil. Pointing device applied to the screen.
- Mouse. Functional device for moving around the computer screen.
- Touch screen. Screen designed to recognize the pressure on the surface. By touching the screen, the user can make a selection or move the cursor, equivalent to the mouse.
- Scanner. Device that, with a light beam, detects light and dark patterns and thus allows a physical image to be converted into a digital signal that reproduces it as it is.
- Joystick. Pointing device that is used most often in computer games, although it is also common in industrial applications to operate devices.
- Code bar scanner. By means of the laser, drawings formed by bars and parallel spaces can be read, thus encoding information.
- Alphanumeric keyboard. The most frequent, with 62 keys including all the numbers and letters, as well as a series of commands.
- Function keyboard. Useful for computer systems, it has 13 configurable letters.
- Digital photo camera. It connects to the computer and transmits the images it captures to it. It can be photos or video.
- Webcam. Like the camera but of small dimensions, not showing the images it takes but simply transmitting them to the computer.