Knowledge about the keyboard

The keyboard is one of the most commonly used input devices in a computer. The main function of the keyboard is to input text and control information to the computer. The input of text information is the most important function, in WIN98 and Win95, the mouse has shared most of the Control Information Input tasks.
Our common keyboard is a 101 or 102 key keyboard. With the advent of Win95 and Win98, the new 104-key keyboard also appeared. The layout of this keyboard is similar to that of the common 101 or 102-key keyboard,One more start key is next to its left and right alt keys. Click it to open the Start menu, and an application key is displayed on the right.
1. keyboard structure and working principle
The shape of the keyboard is roughly rectangular. It is connected to a middle-section spiral cable on its top. The other end of the cable is a din connector which can be connected to the keyboard socket of the motherboard. The work of the keyboard is mainly controlled by its built-in single-chip microprocessor, which controls the keyboard power-on self-check, scan code interpretation and buffering, as well as the communication between the keyboard and the host. When the keyboard key is pressed, the microprocessor interprets the corresponding Digital Signal Based on the pressed position and sends it to the computer's central processor. If the central processor is busy, however, you cannot process your input immediately. The microprocessor sends the content you typed to the keyboard buffer and waits until the CPU is idle.
2. Category of the keyboard
The keyboard can be divided into mechanical touch type keyboard, Capacitive keyboard and thin-film keyboard based on the contact structure of the buttons, but the surface is very difficult to distinguish. Based on the number of keys, the keyboard can be divided into 83/84 keys and 101/102 keys.And 104-key keyboard (that is, Win95 keyboard. Currently, Win95 keyboards are favored.
Based on the different keyboard plug, the keyboard can be divided into a five-core cable keyboard and a six-core cable keyboard, in fact, the two types of keyboard transmit the same signal, as long as you add a connector to achieve mutual conversion.
3. keyboard connection
Now let's take the five-core cable keyboard as an example to see how to connect the keyboard to the host. First, find the five-core socket at the back of the host. Note that you should pay attention to the direction when inserting the keyboard, the plug can be inserted into the socket only when the direction is correct. Note that there is a concave position on the socket, and then there is also a concave position on the keyboard plug. As long as the plug is inserted into the socket, the keyboard is connected to the host.
4. keyboard Partition
As we have already said, the most common keyboards are 101/102 and 104 keys. The distribution of these keys is very similar. Take the 104 key keyboard as an example and divide it by function, we can divide the keyboard into four areas: ① Function key area, ② typing key area, ③ editing control key area, and ④ secondary key area. In addition, there are three indicators in the upper right corner of the keyboard.
5. function key area Introduction
The function key area is a row of buttons on the upper part of the keyboard, from left to right: ESC key, usually used to exit or cancel; followed by F1 ~ F12 has 12 function keys in total, which are generally used as "shortcut keys"; print screen keys. In a DOS environment, the function is to print the screen information. In a Windows environment, the function is to save the display of the screen as a graph to the memory for processing. The scroll Lock key can lock the scroll bar in some environments, and there is a scroll lock indicator on the right, indicates locking; the pause/Break Key is used to pauseProgramOr command execution.
6. Introduction to the typing key area and editing Control Area
The keys in the typing key area are mainly composed of the primary key, number key, symbol key, and tabulation key. The number and sequence of keys are basically the same as those in the standard English typewriter, you can enter various commands in the typing key area, but it is generally used together with the editing control area for text input and editing.
The editing control area is used to control the movement of the cursor.
7. Introduction to secondary key areas
The secondary key area is added to increase the speed of digital input. It is composed of the most common keys in the typing key area and the editing control area. It is generally compiled into a layout suitable for the right hand to operate separately. Only one Num Lock key is special. It is the switch key between the number input and the edit control status. The num lock indicator on the top shows the status. When the indicator is on, it indicates that the secondary key area is in the Digital Input status, and vice versa.
8. Selection of keyboards
There are many types of keyboards. The selection criteria are mainly based on the principle of personal comfort. The feel of the keyboard is very important and should not be too light or too heavy. In terms of selection type, if you are using Win98 or Win95, you can choose to use the 104-key Win95 keyboard. IN Win95, it provides some shortcut keys. In addition, pay attention to the layout of the keyboard keys, because the distribution of the keys produced by different manufacturers is different, select the distribution of keys you are used. The next step is to pay attention to the keyboard brand. Generally, you should select a good brand and a good quality keyboard.