<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html lang="en-us" xml:lang="en-us"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="copyright" content="(C) Copyright IBM Corporation 2005" /> <meta name="DC.rights.owner" content="(C) Copyright IBM Corporation 2005" /> <meta name="security" content="public" /> <meta name="Robots" content="index,follow" /> <meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' /> <meta name="DC.Type" content="reference" /> <meta name="DC.Title" content="Double-byte character set fundamentals" /> <meta name="abstract" content="Some languages, such as Chinese, Japanese, and Korean, have a writing scheme that uses many different characters that cannot be represented with single-byte codes. To create coded character sets for such languages, the server uses two bytes to represent each character. Characters that are encoded in two-byte code are called double-byte characters." /> <meta name="description" content="Some languages, such as Chinese, Japanese, and Korean, have a writing scheme that uses many different characters that cannot be represented with single-byte codes. To create coded character sets for such languages, the server uses two bytes to represent each character. Characters that are encoded in two-byte code are called double-byte characters." /> <meta name="DC.subject" content="DBCS (double-byte character set), definition, double-byte data, basic information" /> <meta name="keywords" content="DBCS (double-byte character set), definition, double-byte data, basic information" /> <meta name="DC.Relation" scheme="URI" content="rbal3dbcs.htm" /> <meta name="DC.Relation" scheme="URI" content="rbal3dbcscs.htm" /> <meta name="DC.Relation" scheme="URI" content="rbal3scdbc.htm" /> <meta name="DC.Relation" scheme="URI" content="rbal3idbc.htm" /> <meta name="DC.Relation" scheme="URI" content="rbal3usingdbd.htm" /> <meta name="DC.Relation" scheme="URI" content="rbal3dbcsize.htm" /> <meta name="DC.Format" content="XHTML" /> <meta name="DC.Identifier" content="rbal3dbcsf" /> <meta name="DC.Language" content="en-us" /> <!-- All rights reserved. Licensed Materials Property of IBM --> <!-- US Government Users Restricted Rights --> <!-- Use, duplication or disclosure restricted by --> <!-- GSA ADP Schedule Contract with IBM Corp. --> <link rel="stylesheet" type="text/css" href="./ibmdita.css" /> <link rel="stylesheet" type="text/css" href="./ic.css" /> <title>Double-byte character set fundamentals</title> </head> <body id="rbal3dbcsf"><a name="rbal3dbcsf"><!-- --></a> <!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script> <h1 class="topictitle1">Double-byte character set fundamentals</h1> <div><p>Some languages, such as Chinese, Japanese, and Korean, have a writing scheme that uses many different characters that cannot be represented with single-byte codes. To create coded character sets for such languages, the server uses two bytes to represent each character. Characters that are encoded in two-byte code are called double-byte characters.</p> <div class="section"><p><a href="#rbal3dbcsf__hrsl338">Figure 1</a> shows alphanumeric characters coded in a single-byte code scheme and double-byte characters coded in a double-byte code scheme.</p> </div> <div class="section"><p>You can use double-byte characters as well as single-byte characters in one application. For instance, you might want to store double-byte data and single-byte data in your database, create your display screens with double-byte text and fields, or print reports with double-byte characters.</p> </div> <div class="section"> <div class="fignone" id="rbal3dbcsf__hrsl338"><a name="rbal3dbcsf__hrsl338"><!-- --></a><span class="figcap">Figure 1. Single-byte and double-byte code schemes</span><br /><img src="rv3h013.gif" alt="Graphic showing examples
of hexadecimal codes for single-byte and double-byte characters." /><br /></div> </div> </div> <div> <ul class="ullinks"> <li class="ulchildlink"><strong><a href="rbal3dbcscs.htm">DBCS code scheme</a></strong><br /> IBM<sup>®</sup> supports two DBCS code schemes: one for the host servers, the other for personal computers.</li> <li class="ulchildlink"><strong><a href="rbal3scdbc.htm">Shift-control double-byte characters</a></strong><br /> When the IBM-host code scheme is used, the server uses shift-control characters to identify the beginning and end of a string of double-byte characters. The shift-out (SO) character, hex 0E, indicates the beginning of a double-byte character string. The shift-in (SI) character, hex 0F, indicates the end of a double-byte character string.</li> <li class="ulchildlink"><strong><a href="rbal3idbc.htm">Invalid double-byte code and undefined double-byte code</a></strong><br /> Invalid double-byte code has a double-byte code value that is not in the valid double-byte code range. The IBM-Host code scheme in the DBCS code scheme topic shows valid double-byte code ranges. This is in contrast to undefined double-byte code where the double-byte code is valid, but no graphic symbol has been defined for the code.</li> <li class="ulchildlink"><strong><a href="rbal3usingdbd.htm">Use double-byte data</a></strong><br /> This section describes where you can use double-byte data and discusses the limitations to its use.</li> <li class="ulchildlink"><strong><a href="rbal3dbcsize.htm">Double-byte character size</a></strong><br /> When displayed or printed, double-byte characters typically are twice as wide as single-byte characters.</li> </ul> <div class="familylinks"> <div class="parentlink"><strong>Parent topic:</strong> <a href="rbal3dbcs.htm" title="This section contains information that you need if you use double-byte characters.">Double-byte character set support</a></div> </div> </div> </body> </html>