Alt and Ctrl are used in combination with other keyboard keys to form special commands.Due to the fact that users often resort to their use, they have an increased size. Special keys are located next to the alphanumeric group of the buttons. Their functions and properties depend on the working program, and in some cases of the operating system.Ī generally accepted function in many programs has the F1 key that calls the help where you can learn the functions of other buttons. Function keysįunction keys are located at the top of the keyboard and they consist of 12 buttons F1 - F12.
When the keyboard is used to enter commands, Enter completes the input and starts its execution. If the computer keyboard is used to enter text data, the paragraph closes by pressing the ENTER key. For hard (permanent) register switching, CAPS LOCK is used. Switching the register (input of lowercase and uppercase characters) is carried out by holding the SHIFT key. Each of the keys can work in different registers, as well as denote several characters. Below is the picture - photo of computer keyboard with a description of key groups.Īlphanumeric keys are used to enter information and commands dialed. The standard keyboard has more than 100 keys distributed by functional groups.
Photo of computer keyboard and key destination
The entered symbol is stored in the keyboard buffer until it takes it to the program for which it is intended, for example, a text editor Microsoft Word.The processor proceeds to a deferred task.The handler sends the code into the keyboard buffer, taking about this processor, then stops its work.Next, under the control of the handler, the processor determines which of the characters it corresponds to this scan code. The program of the interrupt handler sends the processor to the keyboard port where the scan code finds.By defining the recording of the program, the processor proceeds to its execution.Each data list record contains the address of the program serving an interrupt that coincides with the recording number. region random access memorycontaining interrupt vector - data list. Having received a fixed interrupt number, the processor appeals to the special.The keyboard port tells the interrupt with a fixed number.Scan code enters the port integrated into the motherboard.After pressing the key, the keyboard microcircuit generates scan code.Therefore, the computer reacts to commands of the main keyboard keys immediately after switching on. The driver you need already exist in the BIOS ROM.
The main functions of the keyboard do not need special software. This article discusses the keyboard device, layout, key assignment, characters and signs. The main device for manual input information, commands and data.
0 kommentar(er)
