The information in this article applies to:
SUMMARY
The ASCII (American Standard Code for Information Interchange)
character set defines a mapping of the letters, numerals, and
specified punctuation and control characters to the numbers from zero
to 127. The term "code page" is used to refer to extensions of the
ASCII character set that also map specified symbols to the numbers
from 128 through 255.
MORE INFORMATION
The ANSI (American National Standards Institute) character set maps
the letters and numerals in the same manner as ASCII. However, ANSI
does not support control characters and it maps many symbols,
including accented letters, that are not mapped in standard ASCII. All
Windows fonts are defined in the ANSI character set.
SCENARIO 1A lowercase ANSI string is passed to the AnsiToOem() function. The result is passed to MS-DOS, which maps the string to uppercase.SCENARIO 2An uppercase ANSI string is passed to the AnsiToOem() function. The string is passed to MS-DOS.This is caused by the fact that the MS-DOS lowercase to uppercase conversion mapping and the Windows ANSI case conversion do not match. To avoid this problem, use the AnsiUpper() function to convert the ANSI string to uppercase before passing it to the AnsiToOem() function. Also note, this is only a problem with extended characters. These problems are often overlooked until your customers call to complain. Keep in mind that both ANSI and OEM are 8-bit character sets. In applications, always use the "unsigned char" type instead of "signed char" for character variables. Problems that result from using "signed char" are very hard to track. The SYSTEM.ini file contains entries that relate to code pages. In the [boot] section, the OEMFONTS.fon line specifies the file that contains the OEM stock font. In the [keyboard] section, the OEMANSI.bin line specifies the ANSI-OEM translation table. If this line is blank, Windows uses the default table built into the keyboard driver. In the [enh] section, the *WOA.fon lines specify the fonts used in an MS-DOS window at various resolutions. Windows does not provide any mechanism for an application to work with data that is not in the current MS-DOS code page, nor does Windows recognize changing the OEM code page in an MS-DOS window. However, an application is free to provide its own translation tables and provide a data format that includes the code page. Additional query words: 3.00
Keywords : kb16bitonly kbSDKWin16 |
Last Reviewed: June 24, 1999 © 2000 Microsoft Corporation. All rights reserved. Terms of Use. |