About character sets
In the early 1980s, the developers of the IBM PC created an ordered list of symbols known as the IBM extended character set. This list contained all the classic ASCII 7-bit characters, together with various mathematical symbols, line and box drawing characters, and some accented characters.
While this was adequate for certain English-speaking countries, it was insufficient for most other countries. For example, there are accented characters in various European languages that are not included in the IBM extended character set. Therefore, a number of other character sets were developed. Each character set, including the original IBM extended character set, is contained in a code page. Each code page is designed for a particular country or group of countries, and each is identified by a three-digit number.
Some examples of the code pages supported by MS-DOS are:
437 English and some Western European languages
850 Most Western European languages
852 Many Eastern European languages
860 Portuguese
863 Canadian French
865 Nordic languages
These are known as OEM code pages (for Original Equipment Manufacturer). The classic IBM extended character set is contained in OEM code page 437 and is the default code page for the United States. DOS considers code page 850 to be the default for most European countries. Code page 850 contains all the letters (but not all the symbols) of code pages 437, 860, 863, and 865; consequently, many of the box-drawing and line-drawing characters contained in these code pages are omitted to make room for accented characters in code page 850.
Each character in a code page is identified with a number; this number (which can be decimal or hexadecimal) is known as a code point. For example, the code point of the numeric character "4" is 52 (decimal) or 34 (hexadecimal) in code pages 437 and 850.
The Windows environment uses its own character set, which is generally known as the ANSI character set. Although this character set shares many characters in common with the OEM code pages, it omits most of the line-drawing characters and mathematical symbols that these code pages offer. Furthermore, even characters shared in common between an OEM code page and the ANSI character set often have different code point numbers.
The global language driver determines the character set used by dBASE Plus. If you have another product already installed on your system that uses the Borland Database Engine (BDE), your current language driver is unchanged when you install dBASE Plus. If no BDE language driver setting is detected, however, dBASE Plus installs the ANSI language driver by default.