Keyboard and Mouse, Computer ChipSet

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The KEYBOARD is the most common input device general purpose computers. Keyboard as an input device data 'target' is the daily work. Presents the basic mouse input device for communicating with a computer and meant for general as PC. Generally, an electromechanical converter that mechanical movements of a button or a combination of keys into a sequence of electrical pulses. With computer keyboards are mainly connected via DIN connector, PS/2 ports, USB and infrared or radio receivers and transmitters. It seems to be like some kind of USB overcome standard configuration.

Arrangement of letters on the keyboard can be controlled with a program for this purpose created programs called DRIVERS (control - in this case for the keyboard).

The arrangement of the keys is classified into four groups:

1.) LETTER keys, letters, digits and special characters.
2.) NUMERIC keys, separate to the right of the letter keys.
3.) FUNCTION keys, above the letter keys (F1-F12).
4.) CONTROL keys, between the letter keys and numeric keys.
 PC keyboard (HR layout)
Figure 3.3.35 The standard PC keyboard (HR layout).

There are different versions of the layout of the keys, but the version shown in Figure 3.3.35 commonly in use. Version displayed may include depending on model 104 or 105 keys, depending on the market (standard) for which it is intended keyboard. Pressing the keyboard electrical contact is achieved in the network guide similar organization ROM, based on which logic circuits recognize the keyboard where the keys word and send the appropriate combination code keypad in the control computer. The code is tailored to work with a keyboard and not any of the previously mentioned. Keyboard controller occasionally read output logic circuits of keypad to determine if there are any changes to it. Keyboard controller and its I / O channels are part of the motherboard of the PC. Newer keyboards have an extra set of keys for switching off the computer and even some other task of which is an interesting set of numeric button that adds new functions to activate the software for mail, calculator in the other. These are mainly related to the Windows program support.

Button layout is shown in Figure 3.3.35 is called QWERTY (QWERTZ), the characters in one of the letter rows. This layout was created with the aim of slowing down typing because the first mechanical typewriters often stuck. Development of typewriters and electronic calculators became noted slowdown and lack of disturbance write faster. Nevertheless habits using this keyboard layout has prevailed. Much better button layout about typing speed is DVORAK (the name of one of the authors - August Dvorak and William Dealey), positioned so that they are more frequently characters placed closer to each other, the English language, of course. So in place of characters q,w,e,r,t,y are signs ",<,>,p,y,f, and in place of characters a,s,d,f,g are signs a,o,e,u,i. But its implementation this schedule is not so far experienced faster typing, despite up to 75%. Standard was established in the first half of last century. The results showed that hand typist in the average daily work on the QWERTY keyboard make time between 25 km and 30 km, while the keyboard of Dvorak make time less than 2 km. This author saw the layout of the keys is in the application only once on a laptop computer company Apple, the characters on the keys were not printed as an alternative label. Know how to use a computer you probably do not know, and involves rapid typing.

Most operating systems include a special feature that the use of use of certain combinations of keys can make an action as the execution of a command or something. Key Combinations for this purpose are called the most basic KEYBOARD SHORTCUTS are described in Appendix h). Although the key combination of very great help, effective use of computers today is unthinkable without a MOUSE.

The main task of MOUSE is to be consistent with the moving arrow-moves the cursor (pointer ) on the screen when the cursor coincides with the displayed image on the screen it is possible to achieve some action by pressing one of the mouse buttons, left (L), intermediate with wheel (K) or right (D). Mouse to the computer sends some data, and therefore considered as an input device PC. With a computer mouse can be connected in various ways, through the serial port (COM), PS/2 ports, USB and infrared or receivers and transmitters, but is likely to prevail as some sort of USB standard configuration. Mechanism for transferring data on the movement of the mouse is transmitted using motion sensors to monitor two directions, as shown in cross-section in the following Figure.

 Mouse with a ball  Easy Miner
Figure** 3.3.36 Mouse with a ball / Optical mouse / Touchpad. ( + / - )  

Moving the mouse turns the ball with his flip transferred to two rollers that have the drive shaft with holes. As the disc rotates light emitting diode (LED) illuminates the sensor and built-in electronics based on data received from the sensor detects how fast and in which direction to turn the disc with holes. Single sensor monitors the vertical axis of the screen and the other horizontal axis. Processed data to the computer sends an electronic circuit. Lack of conception is often shown soiling rollers and the need for a balanced and appropriate surface on which the mouse moves in order to achieve better friction between the balls and the substrate.

A new generation of mice used for motion detection camera which analyzes the image background and follows the direction in which the changes occur. The electronic circuitry is complex, but in an era of smaller and more powerful electronics this solution is quite cheap. Processed data to the computer sends an electronic circuit in the same form as in the previous case with the ball. Such 'optical' mouse (Figure 3.3.36b) usually has some sort of LED backlighting that the image that the camera gets it usable. Optical mice do not require specific background, but they matter a reflective surface such as glass. But the players are made specific substrate and mice with additional buttons, which essentially does not change the concept. Instead of LED lighting is used to illuminate the surface and the LASER, which allows getting a finer image resolution and therefore more precise indication of the mouse.

The use of a TRACKBALL is still used, with lever mechanism that attaches to the keyboard, mobile computer (laptop) or in a separate case, which is actually the concept of an inverted mouse with a ball. But for a laptop this is not a practical solution and recently installed the trackpad (TOUCHPAD) to which are added the necessary buttons, as shown in the example shown in Figure 3.3.36c. There are solutions that fully resemble a small joystick. Joystick or game console also fall in computer input devices.

To make all the components of a computer and its attached devices can successfully function as a single unit takes care of the common set of electronic logic components integrated into one or more integrated circuits called CHIPSET, which is the task of successfully managing and sharing data between different devices inside the computer and additional connected devices . Diversity in design and function is primarily related to the type of processor. Leading PC manufacturers in the world such as Intel, AMD (Advanced Micro Devices), VIA, Ali (Acer Labs Inc.) And SIS (Silicon Integrated Systems). Other manufacturers like Sun or SILICON GRAPHICS designed, manufactured or ordered chipset's own needs.

Basically chipset consists of integrated circuits with systems to support graphical resources and peripherals. Seen as the two basic units can be displayed as shown below.

 Block scheme - Chipset Intel i815  / z370
Figure* 3.3.37 Block diagram of old and newer chipsets / Chipsets. ( + / - )

The entire set of logic, as the Figure shows, is divided into two parts:

Figure 3.3.37 chipset supports communication with the PCI and ISA devices and PATA 33/66/100 standard for communication with the hard disk. It has a built-in internal graphics support with 2D and 3D acceleration, which can be supplemented by additional SDRAM unit or can be installed another graphics card. Supports traditional NTSC and PAL TV standard output, which is supplied with the DVD software makes interesting multimedia solutions. Significant support for USB devices (modem, mouse, keyboard, camera, scanner ...) which is a rapid simple bus (up to 12 Mbps - megabits a second) in the CBA architecture can easily connect to a computer without his fire (hot plugging). USB standard supports up to 127 external devices with PnP (Plug and Play) mode settings dynamically. Devices for network support based AMR / CNR (Audio Modem Riser / Communication and Network Riser) concept for modem and LAN communications are not in its promotion practices.

Names of chips (north and south chip) probably assigned to them according to their positions in the block diagram (Map) work. Number of PCI slots and possible attached devices just generally shown. Construction motherboard, although it is possible fitted with the same chipset, can vary significantly. Plates with fewer elements and connections will be used in small 'desktop' enclosures while plates with more elements and for example with support for two processors to be installed in the greater will be the big 'tower' case. Newer versions of chipsets that support PCI and PCI Express technology is presented in Chapter 3.5.3, and versions that support PCI-Express technology, the new generation are shown in Chapter 3.5.10. The descriptions in the Chapters whereby water couplings images motherboard itself show that two previously shown that the chip is not sufficient to conduct all the tasks necessary for the functional operation of the computer.


Unquestionably, CRT monitors are retiring. As stated above LCD technology has a defect in the visual field that individual companies will settle more successful than others, so before purchasing a good bit of 'see' certain types of monitors. In addition to this problem and have a 'black'. Specifically, if the control signal such that the light does not pass, the filters are not able to completely prevent the passage of light and can not quite get the 'black'. How much has the transistors that control the image, in the process of making known to happen that some parts of the pixel (one of the transistors in triode) completely missing or leaking light, which manifests itself as a permanent black dots or bright points of some basic colors, because the driver faulty transistor. Few other manufacturer offers LCD monitors without any defective pixels (zero-pixel-defect warranty). Polarizing filter with the light source in Figure 3.3.29c and 3.3.29d do not stand in the same position and are placed vertically or horizontally. In practice, it is more frequently the case that the output filter vertically as shown 3.3.29d. LCD technology uses a similar effect for the figures on small calculators. The difference is that calculators have no backlight, but used the effect of reflection of light from the background. This effect using portable measuring instruments or watches. If no external light still nothing. So watches have built a small light that can be turned on as needed.

LCD, plasma and OLED monitors use Digital management of picture elements, which eliminates the need for digital-to-analog conversion in a graphical system looks for the picture. But the picture is analogous, regardless of whether it was originally brought to this or is converted to analog from digital data obtained. LCD and OLED displays have better contrast and brightness of a CRT monitor but the image quality is good only at the native resolution of the monitor, the picture is contrary to 'smear'. As of the triode physically horizontally and vertically defines a working resolution, should be careful when choosing your monitor to not choose the small screen (say 15") with a very high resolution (e.g. 1600×1200), because then the letters shown little hard. To take advantage of the features of a digital video signal, monitors and video card must have the ability to transfer and processing of these signals, which are known to have incorporated DVI 29-pin connector (Digital Visual Interface). Various versions of DVI interfaces are able to communicate with analog data transmission, digital transmission of data, or both, of which one is chosen. LCD monitors have a better circuit boards and connectors for VGA and DVI interface. Multimedia requirements, signal transfer images and sound the same connecting cable, contributing to the development and wider use of HDMI (High Definition Multimedia Interface) standards and connections to each other by various function easily connect multimedia devices.

Sometimes it is necessary to transfer the image from the screen at a greater distance, for example, when it comes to PROJECTORS. It was then that one of the solutions to order video cable lengths required in which to make the length of adequate compensation in respect compromising transmission signal. A possible solution is to use a VGA-UTP Extender which allows its receiving and transmitting part of the image to the monitor screen pass to the projector remotely over 100 m of computers over a network UTP CAT5 cable. Some of the solutions can transmit video signal quality and HD1080.

The range of input and output devices is growing daily and the function of diverse and often have integrated both functions. In the context of the tasks described computer network card (NIC - Network Interface Card) is an input/output device because it establishes bidirectional communication either alternately or simultaneously (half-duplex or full-duplex) with a network device. These can argue for BLUETOOTH.


Citing of this page:
Radic, Drago. " IT - Informatics Alphabet " Split-Croatia.
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