2.2.3. Other codes

Americans had during the development of communication techniques care much about others (America is the home of modern science), and the use of computer technology in Croatia represented a problem for Croatia particular graphemes 'ČĆĐŠŽ čćđšž'. The problem was initially solved and refit the curly brackets and some special characters. Specifically, the ASCII code is not immediately conceived with 8 bits, and the local graphemes rewrite the 7-bit code-term replacements. Cards that had embedded ASCII graphemes had to rewrite the Croatian needs. Lodging us specific grapheme is assigned to hexadecimal locations, as follows.

Table 2.2.2 Accommodation of graphemes specific for Croatia.

Other countries was solved same problem in a similar way. Standards today are dictates program support based on PCs and will continue to review only relate to them.

American code tables called 437 - UNITED STATES, and when they appear on a computer based on its modifications, it is on the graphics card and the printer make appropriate reparation content character memory graphics card and printer in which the records of the form of characters (graphemes).

Modification of the original characters in the ASCII code 437 code table at the locations and square braces is one of the solutions will in Croatia CROSCII popularly called, but the purposeful use of the code that allows the 'installation' character of the site to complement the general code tables 850th. In this way, using two alternate code tables (437 and 850) do not lose the original character ASCII code.

But the development of computer technology and computational techniques strengthen the market outside of the area USA, prompted the manufacturers of the equipment and software to support the establishment of a code table adapted to other states and localities.

Allowed to use the local code table so that they remained preserved the basic ASCII characters and additional 128 characters specific to each country. Of course, there is no solid world standards, but pretty much everyone is holding what is published by the American company 'IBM' who signs Croatian letters built into the code table 852 (Latin II) for MS-DOS applications, and for other countries announced code tables with other number, and 'Microsoft' and Table 1250 (Latin 2) for MS-Windows applications, and appropriate for other countries. 1250 code table is very similar table ISO 8859-2 (Latin 2) recommended by the International Standards Organization. The difference is in the specific signs that the 'Microsoft' is used in their applications as well as special tags and commands and why graphemes 'ŠšŽž', unfortunately Croats, have changed places. The table above shows the placement of Croatian specific characters.

Special activities, dealing with coding information for the purpose of protecting them from unauthorized inspection is called CRYPTOGRAPHY. At the basis of this method is that it constantly changes associated code substitute for individual code elements controlled by a key generator so ENCRYPTS data before sending the message or during the shipment. The same generator in the process of receipt of data, decryption of data. Diversity in mixing coding elements, number substitution code without repeating sequences within the ENCRYPTION process and the time required to repeat the whole sequence, the parameters are used to assess the quality of key generator.

Regarding faster data remotely using special methods of coding can be achieved, and their COMPRESSION. A good compressor can be up to 6 times to reduce the overall volume of data before forwarding the message. The destination DECOMPRESSION procedure is performed, and the data is 'unpacked' in the original form. In this way greatly reduces the transmission time of data remotely. Therefore, lossless original content.

Compression is of great importance in data ARCHIVING procedures on the media for permanent memory, because in this way multiplies the capacity of storage media. Compression methods are diverse but all share the foundation of shortening codes that are repeated as content 'xxxxxxxxxxxxx' would be turned into '13x 'and thereby shorten multiple volume data for transmission or storage.

Particularly significant is the encoding of image data. As the image quality is closely related to the number of picture elements and their attributes (such as brightness, color, etc.), the volume of data describing the image is very large. Today's computers can handle the picture and resolution over 1600 × 1200 elements in thousands of colors, and have to transfer and store images developed various methods of encoding and compression of individual elements of the entire contents. Association Vendor VESA (Video Electronic Standards Association) in the USA in this respect has developed a standard that many accidents.

Most of the above described and incorporates a standard called ISO (International Standards Organization), International Association of Geneva, whose task is to adopt international standards for scientific and technical activities.

2.2.4. Unicode

How is the climate different uses different code, in practice, a problem arises when transmitting coded texts various national variants of ASCII code. Only letters of the English alphabet, numbers and punctuation part one can be considered safe in the data transfer.

All these versions have the following common disadvantages:

• Use for display only a small subset of the characters, so when it is necessary to write the text with our letters and German umalutims, it is not possible.
• PCs that are not equipped for a given subset fonts can not display such text.
• Required transformations from one standard to another.

The above problem is solved 'Unicode', spread world-wide standard that allows the representation of a letter, technical symbols and special characters, based on ISO / IEC 10646. On Linux and Unix operating systems, this code is marked as UTF-8. Traditional character set of 8 bits that is used called SBCS (Single-Byte Character Set) with 256 characters to Croatia for the Windows operating system, code is 1250, indicating 'Central Europe' (charset = windows-1250). Older Windows systems are not supported by Unicode (Me/98/95), but can be upgraded by downloading and installing 'The Microsoft Layer for Unicode - MSLU'. Unicode is one of a group of DBCS (Double-Byte Character Set), then 16-bit and allows you to display a large number of characters without moving from one table to another. The heirs of the Windows NT operating system like Windows XP operating system will automatically recognize which character set is concerned. This user does not notice in Croatia because the Word with <ALT> + <0138> i <ALT> + <0352> to get the same character ' Š '. Now Windows code table that is used in Croatia 1250 is labeled with the indication 'ANSI - Central Europe', in Croatia we have a little problem, because once we change the accustomed code table.

For another country they will be associated graphemes on numbers elsewhere. True, there are those versions and variants of Unicode's pretty, but it was stated as a base enough. The correct view Croatian letters in support of the program Microsoft Word supports Font 'Arial', and does not support font 'Times New Roman' for the letter 'DŽ' and its variants show. To avoid any confusion, the letter 'DŽ' and other things like it are two characters rather than one character. The author of this text was not checked by sorting Unicode support in the program Word or Excel or another of this type. Just so you do not forget; Left key <ALT> does not the same function as the right <ALT> key on the keyboard of Croatia (according to Appendix 9h combinations of keys). Part of Unicode standard, specific for Croatia, who use the Windows operating system is shown in Appendix 9g.

They did not dispute the only Croatian specific graphemes, or graphemes some other country, but can also use special characters profession and other languages that can be seen on page Unicode: UTF-8 coding maintained by Eni Generalic on his site Periodic Table of the Elements. You can see more about the UTF-8 code on the pages of this e-book in the corresponding page inside inslosure or among the pages on specific IT terms.

SUMMARY:

A special group of codes makes STRIPED CODE (BAR CODE), track by dashes, a special arrangement of thick and thin lines, which describes a numerical, letter or both information. This record is used for automatic identification, and can be read by reading the code that the striped paper uses optical principles, and that the computer will transmit the appropriate binary data based on the read. It can be seen on almost all products in the store. Advanced version of bar code is a QR code (Quick Response code), matrix bar code (two-dimensional code), and it is characterized by fast readability and large storage option. Coded information may consist of any data, binary, alphanumeric, symbols and more. Both types of code is shown in the picture and sub-picture on the left in the heading of this paragraph.

There is one specific way of coding - BEEP CODE. Computer manufacturers built into the BIOS (Basic Input / Output System) is a computer program that mali series of short and long combination of wheezing in computer speakers - BEEP signals to alert the user that when you turn the computer detected an error or a computer to test the functionality of the basic components essential for computer operation (POST - Power On Self Test). Generally, if your computer is fine, one will hear a short 'beep'. But manufacturers bios as AMI, Award, IBM, Phoenix and others have not agreed on a standard method of advertising, and a computer that is incorrect and tone up with some combination of beeps, you first need to determine which BIOS is and then consulted his instruction in which is described the combination of means. More than useful. If no signal is something wrong with the power supply, if there is any signal means that the microprocessor does, he launched the POST program found that one of the essential components of a computer is not correct, as working memory, video card, keyboard, part on the motherboard or something else.

The concept of coding and code compliance and the use of code is of great importance in the application of computer technology. It can not be expected to result in the efficient processing and use of data, for example, if your computer is running the code table that you used your printer does not support. The problem can be significant if it happens that codes for specific graphic features of the printer (because not all the same) do not have an adequate program support (driver) and incorporated into the computer that the printer is connected.

In the Croatian territory has long been a problem in the variety of application code table (three for ASCII and Unicode and CROSCII) which requires about preserving our catch interpreter application in the case of going from one table to another code executed restructuring (REMAP) data to be processed. Standardization of the code is very great importance. One can not expect performance data bank in one of the network nodes, if the data is stored in accordance with generally accepted standards.

Know what the code is of great importance for the successful use of computers and computer programs, particularly with regard to development of program support. All instructions that a computer receives a set of thoughtful and special way of coded commands and commands in a way that a computer can be sequentially executed without error. A single modified sign (number) stored in the computer records can lead to 'fall' system. This is precisely the task of maliciously made program, called viruses, that 'plagued' by the computer (operating and permanent memory) altering or deleting records coded user and causing great and often irreparable damage.