In any computing system, certain input devices are required. Without them, the system can be compared with a deaf and blind person who is deprived of the opportunity to receive information from the outside world.
Many authors, describing
devices for inputting information into a PC, completely miss the fact that the list of such solutions is not limited only to familiar components. This is only partially true. Temperature, light sensors, recorders of
sound vibrations, traps of moisture particles, units for measuring wind strength, etc. - these are also input devices. Why? Because these above-mentioned devices just form the data stream into the computer system.
Common means familiar
Input devices in an average computer, of course, are unlikely to include any of the above. Still, various sensors are used to solve quite specific tasks that most users are unlikely to ever encounter. Therefore, we will dwell on well-known devices. So, the main input devices are the keyboard, mouse, joystick, trackball, pedal and steering wheel, light pen, scanner, touch panel.
The keyboard is a set of alphanumeric buttons placed in a special case - the keyboard board (hence the English name - keyboard). A distinctive feature of this device is that to work as part of the computer does not require any drivers. If you disassemble its case, then you can see the control chip of the controller. When you click on any button, the corresponding binary code is generated , which is recognized by the firmware written in the ROM of the base input / output system of the motherboard. In other words, the keyboard driver is part of the BIOS codes. Thanks to this, it is possible to work with the BIOS through this input device even without installing any operating system. In portable versions of computers, the keyboard is part of the case.
The arrangement of characters is usually standardized - the first row of letters of the alphabet is a sequence of QWERTYUIOP ... (or YTsUKENGSH ...). The reason for this placement is the desire of the creators of the device to make it as close as possible to typewriters of that time. Subsequently, attempts were made to change the established standard (for example, the Dvorak solution), however, so far no one has been able to achieve significant success in this direction.
The mouse is the main device for working with graphic elements of modern operating systems and application programs. When the manipulator moves along the surface, its relative coordinates are transmitted to the computer and converted to the cursor cursor.
The classic solution involves a scheme with four buttons and a wheel, but there are many models in which the number of buttons is increased. An alternative to a mouse is a trackball. To move the cursor, you need to scroll the ball with your palm.
The pedal and steering wheel are in demand by fans of computer games. Especially automobile and flight simulators. A necessary requirement for work is the support of this group of devices in a gaming application. The driver perceives the steering wheel offsets and the position of the pedals and transfers this data to a program that processes it in accordance with the game situation.
Most devices connect to external ports on the computing system. However, sometimes you can find a pci input device. Its main difference is the connection of the control (interface) card to the computer system bus .