diff --git a/intl/uconv/ucvtw/Makefile.in b/intl/uconv/ucvtw/Makefile.in
index 3e186e060dd..7c8094744c2 100644
--- a/intl/uconv/ucvtw/Makefile.in
+++ b/intl/uconv/ucvtw/Makefile.in
@@ -31,6 +31,7 @@ CSRCS		=  \
 CPPSRCS		= \
                   nsBIG5ToUnicode.cpp \
                   nsUnicodeToBIG5.cpp \
+                  nsUnicodeToBIG5NoAscii.cpp \
 		  nsUCvTWSupport.cpp \
                   nsUCvTWDll.cpp \
 		  $(NULL)
diff --git a/intl/uconv/ucvtw/nsBIG5ToUnicode.cpp b/intl/uconv/ucvtw/nsBIG5ToUnicode.cpp
index 348adcccf56..ed2ab57ecaa 100644
--- a/intl/uconv/ucvtw/nsBIG5ToUnicode.cpp
+++ b/intl/uconv/ucvtw/nsBIG5ToUnicode.cpp
@@ -18,16 +18,11 @@
  */
 
 #include "nsBIG5ToUnicode.h"
+#include "nsUCvTWDll.h"
 
 //----------------------------------------------------------------------
 // Global functions and data [declaration]
 
-static PRUint16 g_BIG5MappingTable[] = {
-#include "big5.ut"
-};
-static PRUint16 g_ASCIIMappingTable[] = {
-  0x0001, 0x0004, 0x0005, 0x0008, 0x0000, 0x0000, 0x007F, 0x0000
-};
 
 static PRInt16 g_BIG5ShiftTable[] =  {
   0, u2BytesCharset,  
@@ -45,8 +40,8 @@ static PRInt16 *g_BIG5ShiftTableSet [] = {
 };
 
 static PRUint16 *g_BIG5MappingTableSet [] ={
-  g_ASCIIMappingTable,
-  g_BIG5MappingTable
+  g_ASCIIMapping,
+  g_utBIG5Mapping
 };
 
 static uRange g_BIG5Ranges[] = {
diff --git a/intl/uconv/ucvtw/nsUCvTWDll.cpp b/intl/uconv/ucvtw/nsUCvTWDll.cpp
index 052b5cd11a1..b65f8efa794 100644
--- a/intl/uconv/ucvtw/nsUCvTWDll.cpp
+++ b/intl/uconv/ucvtw/nsUCvTWDll.cpp
@@ -48,6 +48,16 @@ static NS_DEFINE_CID(kComponentManagerCID, NS_COMPONENTMANAGER_CID);
 PRInt32 g_InstanceCount = 0;
 PRInt32 g_LockCount = 0;
 
+PRUint16 g_ufBig5Mapping[] = {
+#include "big5.uf"
+};
+PRUint16 g_utBIG5Mapping[] = {
+#include "big5.ut"
+};
+PRUint16 g_ASCIIMapping[] = {
+  0x0001, 0x0004, 0x0005, 0x0008, 0x0000, 0x0000, 0x007F, 0x0000
+};
+
 typedef nsresult (* fpCreateInstance) (nsISupports **);
 
 struct FactoryData
diff --git a/intl/uconv/ucvtw/nsUCvTWDll.h b/intl/uconv/ucvtw/nsUCvTWDll.h
index 14e29614830..89ea719f13a 100644
--- a/intl/uconv/ucvtw/nsUCvTWDll.h
+++ b/intl/uconv/ucvtw/nsUCvTWDll.h
@@ -24,5 +24,8 @@
 
 extern "C" PRInt32 g_InstanceCount;
 extern "C" PRInt32 g_LockCount;
+extern "C" PRUint16 g_ufBig5Mapping[];
+extern "C" PRUint16 g_utBIG5Mapping[];
+extern "C" PRUint16 g_ASCIIMapping[];
 
 #endif /* nsUCvTWDll_h___ */
diff --git a/intl/uconv/ucvtw/nsUnicodeToBIG5.cpp b/intl/uconv/ucvtw/nsUnicodeToBIG5.cpp
index c293cd9f574..131a61d3dbf 100644
--- a/intl/uconv/ucvtw/nsUnicodeToBIG5.cpp
+++ b/intl/uconv/ucvtw/nsUnicodeToBIG5.cpp
@@ -18,13 +18,11 @@
  */
 
 #include "nsUnicodeToBIG5.h"
+#include "nsUCvTWDll.h"
 
 //----------------------------------------------------------------------
 // Global functions and data [declaration]
 
-static PRUint16 g_ufBig5Mapping[] = {
-#include "big5.uf"
-};
 
 static PRUint16 gAsciiShiftTable[] =  {
   0, u1ByteCharset,
@@ -36,12 +34,9 @@ static PRUint16 gBig5ShiftTable[] =  {
   ShiftCell(0,   0, 0, 0, 0, 0, 0, 0),
 };
  
-static PRUint16 g_AsciiMapping[] = {
-  0x0001, 0x0004, 0x0005, 0x0008, 0x0000, 0x0000, 0x007F, 0x0000
-};
 
 static PRUint16 *g_Big5MappingTable[2] = {
-  g_AsciiMapping,
+  g_ASCIIMapping,
   g_ufBig5Mapping
 };
 
diff --git a/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.cpp b/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.cpp
new file mode 100644
index 00000000000..80dd1476248
--- /dev/null
+++ b/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.cpp
@@ -0,0 +1,60 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are Copyright (C) 1998
+ * Netscape Communications Corporation.  All Rights Reserved.
+ */
+
+#include "nsUnicodeToBIG5NoAscii.h"
+#include "nsUCvTWDll.h"
+
+//----------------------------------------------------------------------
+// Global functions and data [declaration]
+
+static PRUint16 gBig5ShiftTable[] =  {
+  0, u2BytesCharset,
+  ShiftCell(0,   0, 0, 0, 0, 0, 0, 0),
+};
+ 
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToBIG5NoAscii [implementation]
+
+nsUnicodeToBIG5NoAscii::nsUnicodeToBIG5NoAscii() 
+: nsTableEncoderSupport( (uShiftTable*) &gBig5ShiftTable, 
+                        (uMappingTable*) &g_ufBig5Mapping)
+{
+}
+
+nsresult nsUnicodeToBIG5NoAscii::CreateInstance(nsISupports ** aResult) 
+{
+  nsIUnicodeEncoder *p = new nsUnicodeToBIG5NoAscii();
+  if(p) {
+   *aResult = p;
+   return NS_OK;
+  }
+  return NS_ERROR_OUT_OF_MEMORY;
+}
+
+//----------------------------------------------------------------------
+// Subclassing of nsTableEncoderSupport class [implementation]
+
+NS_IMETHODIMP nsUnicodeToBIG5NoAscii::GetMaxLength(const PRUnichar * aSrc, 
+                                              PRInt32 aSrcLength,
+                                              PRInt32 * aDestLength)
+{
+  *aDestLength = 2 * aSrcLength;
+  return NS_OK_UENC_EXACTLENGTH;
+}
diff --git a/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.h b/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.h
new file mode 100644
index 00000000000..46cb9e3249a
--- /dev/null
+++ b/intl/uconv/ucvtw/nsUnicodeToBIG5NoAscii.h
@@ -0,0 +1,55 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * The contents of this file are subject to the Netscape Public License
+ * Version 1.0 (the "License"); you may not use this file except in
+ * compliance with the License.  You may obtain a copy of the License at
+ * http://www.mozilla.org/NPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * The Original Code is Mozilla Communicator client code.
+ *
+ * The Initial Developer of the Original Code is Netscape Communications
+ * Corporation.  Portions created by Netscape are Copyright (C) 1998
+ * Netscape Communications Corporation.  All Rights Reserved.
+ */
+
+#ifndef nsUnicodeToBIG5NoAscii_h___
+#define nsUnicodeToBIG5NoAscii_h___
+
+#include "nsUCvTWSupport.h"
+
+//----------------------------------------------------------------------
+// Class nsUnicodeToBIG5NoAscii [declaration]
+
+/**
+ * A character set converter from Unicode to BIG5NoAscii.
+ *
+ */
+class nsUnicodeToBIG5NoAscii : public nsTableEncoderSupport
+{
+public:
+
+  /**
+   * Class constructor.
+   */
+  nsUnicodeToBIG5NoAscii();
+
+  /**
+   * Static class constructor.
+   */
+  static nsresult CreateInstance(nsISupports **aResult);
+
+protected:
+
+  //--------------------------------------------------------------------
+  // Subclassing of nsEncoderSupport class [declaration]
+
+  NS_IMETHOD GetMaxLength(const PRUnichar * aSrc, PRInt32 aSrcLength, 
+      PRInt32 * aDestLength);
+};
+
+#endif /* nsUnicodeToBIG5NoAscii_h___ */