diff --git a/icu4c/source/common/ucnvmbcs.c b/icu4c/source/common/ucnvmbcs.c
index 96850355bbe..2411260ac16 100644
--- a/icu4c/source/common/ucnvmbcs.c
+++ b/icu4c/source/common/ucnvmbcs.c
@@ -1,7 +1,7 @@
 /*
 ******************************************************************************
 *
-*   Copyright (C) 2000-2009, International Business Machines
+*   Copyright (C) 2000-2010, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
@@ -398,6 +398,76 @@ gb18030Ranges[13][4]={
 /* bit flag for UConverter.options indicating GB 18030 special handling */
 #define _MBCS_OPTION_GB18030 0x8000
 
+/* bit flag for UConverter.options indicating KEIS,JEF,JIF special handling */
+#define _MBCS_OPTION_KEIS 0x01000
+#define _MBCS_OPTION_JEF  0x02000
+#define _MBCS_OPTION_JIPS 0x04000
+
+#define KEIS_SO_CHAR_1 0x0A
+#define KEIS_SO_CHAR_2 0x42
+#define KEIS_SI_CHAR_1 0x0A
+#define KEIS_SI_CHAR_2 0x41
+
+#define JEF_SO_CHAR 0x28
+#define JEF_SI_CHAR 0x29
+
+#define JIPS_SO_CHAR_1 0x1A
+#define JIPS_SO_CHAR_2 0x70
+#define JIPS_SI_CHAR_1 0x1A
+#define JIPS_SI_CHAR_2 0x71
+
+enum SISO_Option {
+    SI,
+    SO
+};
+typedef enum SISO_Option SISO_Option;
+
+static int32_t getSISOBytes(SISO_Option option, uint32_t cnvOption, uint8_t *value) {
+    int32_t SISOLength = 0;
+
+    switch (option) {
+        case SI:
+            if ((cnvOption&_MBCS_OPTION_KEIS)!=0) {
+                value[0] = KEIS_SI_CHAR_1;
+                value[1] = KEIS_SI_CHAR_2;
+                SISOLength = 2;
+            } else if ((cnvOption&_MBCS_OPTION_JEF)!=0) {
+                value[0] = JEF_SI_CHAR;
+                SISOLength = 1;
+            } else if ((cnvOption&_MBCS_OPTION_JIPS)!=0) {
+                value[0] = JIPS_SI_CHAR_1;
+                value[1] = JIPS_SI_CHAR_2;
+                SISOLength = 2;
+            } else {
+                value[0] = UCNV_SI;
+                SISOLength = 1;
+            }
+            break;
+        case SO:
+            if ((cnvOption&_MBCS_OPTION_KEIS)!=0) {
+                value[0] = KEIS_SO_CHAR_1;
+                value[1] = KEIS_SO_CHAR_2;
+                SISOLength = 2;
+            } else if ((cnvOption&_MBCS_OPTION_JEF)!=0) {
+                value[0] = JEF_SO_CHAR;
+                SISOLength = 1;
+            } else if ((cnvOption&_MBCS_OPTION_JIPS)!=0) {
+                value[0] = JIPS_SO_CHAR_1;
+                value[1] = JIPS_SO_CHAR_2;
+                SISOLength = 2;
+            } else {
+                value[0] = UCNV_SO;
+                SISOLength = 1;
+            }
+            break;
+        default:
+            /* Should never happen. */
+            break;
+    }
+
+    return SISOLength;
+}
+
 /* Miscellaneous ------------------------------------------------------------ */
 
 /**
@@ -1724,6 +1794,12 @@ ucnv_MBCSOpen(UConverter *cnv,
             /* set a flag for GB 18030 mode, which changes the callback behavior */
             cnv->options|=_MBCS_OPTION_GB18030;
         }
+    } else if(uprv_strstr(pArgs->name, "KEIS")!=NULL) {
+        cnv->options|=_MBCS_OPTION_KEIS;
+    } else if(uprv_strstr(pArgs->name, "JEF")!=NULL) {
+        cnv->options|=_MBCS_OPTION_JEF;
+    } else if(uprv_strstr(pArgs->name, "JIPS")!=NULL) {
+        cnv->options|=_MBCS_OPTION_JIPS;
     }
 
     /* fix maxBytesPerUChar depending on outputType and options etc. */
@@ -3859,6 +3935,7 @@ ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
     uint32_t stage2Entry;
     uint32_t asciiRoundtrips;
     uint32_t value;
+    uint8_t si_value[2], so_value[2], si_value_length, so_value_length;
     int32_t length, prevLength;
     uint8_t unicodeMask;
 
@@ -3930,6 +4007,10 @@ ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
     sourceIndex= c==0 ? 0 : -1;
     nextSourceIndex=0;
 
+    /* Get the SI/SO character for the converter */
+    si_value_length = getSISOBytes(SI, cnv->options, si_value);
+    so_value_length = getSISOBytes(SO, cnv->options, so_value);
+
     /* conversion loop */
     /*
      * This is another piece of ugly code:
@@ -4019,8 +4100,14 @@ ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                             length=1;
                         } else {
                             /* change from double-byte mode to single-byte */
-                            value|=(uint32_t)UCNV_SI<<8;
-                            length=2;
+                            if (si_value_length == 1) {
+                                value|=si_value[0]<<8;
+                                length = 2;
+                            } else if (si_value_length == 2) {
+                                value|=si_value[1]<<8;
+                                value|=si_value[0]<<16;
+                                length = 3;
+                            }
                             prevLength=1;
                         }
                     } else {
@@ -4028,8 +4115,14 @@ ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                             length=2;
                         } else {
                             /* change from single-byte mode to double-byte */
-                            value|=(uint32_t)UCNV_SO<<16;
-                            length=3;
+                            if (so_value_length == 1) {
+                                value|=so_value[0]<<16;
+                                length = 3;
+                            } else if (so_value_length == 2) {
+                                value|=so_value[1]<<16;
+                                value|=so_value[0]<<24;
+                                length = 4;
+                            }
                             prevLength=2;
                         }
                     }
@@ -4239,8 +4332,14 @@ getTrail:
                             length=1;
                         } else {
                             /* change from double-byte mode to single-byte */
-                            value|=(uint32_t)UCNV_SI<<8;
-                            length=2;
+                            if (si_value_length == 1) {
+                                value|=si_value[0]<<8;
+                                length = 2;
+                            } else if (si_value_length == 2) {
+                                value|=si_value[1]<<8;
+                                value|=si_value[0]<<16;
+                                length = 3;
+                            }
                             prevLength=1;
                         }
                     } else {
@@ -4248,8 +4347,14 @@ getTrail:
                             length=2;
                         } else {
                             /* change from single-byte mode to double-byte */
-                            value|=(uint32_t)UCNV_SO<<16;
-                            length=3;
+                            if (so_value_length == 1) {
+                                value|=so_value[0]<<16;
+                                length = 3;
+                            } else if (so_value_length == 2) {
+                                value|=so_value[1]<<16;
+                                value|=so_value[0]<<24;
+                                length = 4;
+                            }
                             prevLength=2;
                         }
                     }
@@ -4502,15 +4607,27 @@ unassigned:
     ) {
         /* EBCDIC_STATEFUL ending with DBCS: emit an SI to return the output stream to SBCS */
         if(targetCapacity>0) {
-            *target++=(uint8_t)UCNV_SI;
+            *target++=(uint8_t)si_value[0];
+            if (si_value_length == 2) {
+                if (targetCapacity<2) {
+                    cnv->charErrorBuffer[0]=(uint8_t)si_value[1];
+                    cnv->charErrorBufferLength=1;
+                    *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
+                } else {
+                    *target++=(uint8_t)si_value[1];
+                }
+            }
             if(offsets!=NULL) {
                 /* set the last source character's index (sourceIndex points at sourceLimit now) */
                 *offsets++=prevSourceIndex;
             }
         } else {
             /* target is full */
-            cnv->charErrorBuffer[0]=(char)UCNV_SI;
-            cnv->charErrorBufferLength=1;
+            cnv->charErrorBuffer[0]=(uint8_t)si_value[0];
+            if (si_value_length == 2) {
+                cnv->charErrorBuffer[1]=(uint8_t)si_value[1];
+            }
+            cnv->charErrorBufferLength=si_value_length;
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         }
         prevLength=1; /* we switched into SBCS */
diff --git a/icu4c/source/data/Makefile.in b/icu4c/source/data/Makefile.in
index 633485427ca..e315a30afd0 100644
--- a/icu4c/source/data/Makefile.in
+++ b/icu4c/source/data/Makefile.in
@@ -258,6 +258,10 @@ ALL_UCM_SOURCE=ibm-37_P100-1995.ucm ibm-1047_P100-1995.ucm $(UCM_SOURCE_CORE) $(
 UCM_FILES = $(ALL_UCM_SOURCE:%=$(SRCDATADIR)/%)
 CNV_FILES = $(ALL_UCM_SOURCE:%.ucm=$(BUILDDIR)/%.cnv)
 CNV_FILES_SHORT = $(ALL_UCM_SOURCE:%.ucm=%.cnv)
+UCM_SOURCE_SPECIAL=$(UCM_SOURCE_EBCDIC_IGNORE_SISO) 
+UCM_FILES_SPECIAL=$(UCM_SOURCE_SPECIAL:%=$(UCMSRCDIR)/%) 
+CNV_FILES_SPECIAL=$(UCM_SOURCE_SPECIAL:%.ucm=$(BUILDDIR)/%.cnv) 
+CNV_FILES_SHORT_SPECIAL=$(UCM_SOURCE_SPECIAL:%.ucm=%.cnv) 
 
 ## RES files
 -include $(LOCSRCDIR)/resfiles.mk
@@ -396,13 +400,13 @@ SPREP_FILES = $(ALL_SPREP_SOURCE:%.txt=$(BUILDDIR)/%.spp)
 SPREP_FILES_SHORT = $(ALL_SPREP_SOURCE:%.txt=%.spp)
 
 ## All generated files
-ALL_FILES = $(DAT_FILES) $(CNV_FILES) $(BRK_FILES) $(CTD_FILES) $(RES_FILES) $(CURR_FILES) $(LANG_FILES) $(REGION_FILES) $(ZONE_FILES) $(COLLATION_FILES) $(BRK_RES_FILES) $(RBNF_FILES) $(TRANSLIT_FILES) $(SPREP_FILES) $(CFU_FILES)
+ALL_FILES = $(DAT_FILES) $(CNV_FILES) $(CNV_FILES_SPECIAL) $(BRK_FILES) $(CTD_FILES) $(RES_FILES) $(INDEX_RES_FILE) $(CURR_FILES) $(LANG_FILES) $(REGION_FILES) $(ZONE_FILES) $(COLLATION_FILES) $(BRK_RES_FILES) $(RBNF_FILES) $(TRANSLIT_FILES) $(SPREP_FILES) $(CFU_FILES)
 ALL_INDEX_SRC_FILES = $(PKGDATA_LIST) $(INDEX_FILE) $(CURR_INDEX_FILE) $(LANG_INDEX_FILE) $(REGION_INDEX_FILE) $(ZONE_INDEX_FILE) $(COLLATION_INDEX_FILE) $(BRK_RES_INDEX_FILE) $(RBNF_INDEX_FILE)
 # a list to use in the .lst files (package-relative)
 COLL_FILES_LIST=$(COLLATION_FILES_SHORT) $(COLLATION_INDEX_RES_SHORT)
 BRK_FILES_LIST=$(BRK_FILES_SHORT) $(CTD_FILES_SHORT) $(BRK_RES_FILES_SHORT) $(BRK_RES_INDEX_RES_SHORT) 
 LOCALE_FILES_LIST= $(RES_FILES_SHORT) $(LANG_FILES_SHORT) $(REGION_FILES_SHORT) $(ZONE_FILES_SHORT)
-MISC_FILES_LIST=$(DAT_FILES_SHORT) $(CNV_FILES_SHORT) $(CURR_FILES_SHORT) $(RBNF_FILES_SHORT) $(RBNF_INDEX_RES_SHORT) $(TRANSLIT_FILES_SHORT) $(SPREP_FILES_SHORT) $(CFU_FILES_SHORT)
+MISC_FILES_LIST=$(DAT_FILES_SHORT) $(CNV_FILES_SHORT) $(CNV_FILES_SHORT_SPECIAL) $(CURR_FILES_SHORT) $(RBNF_FILES_SHORT) $(RBNF_INDEX_RES_SHORT) $(TRANSLIT_FILES_SHORT) $(SPREP_FILES_SHORT) $(CFU_FILES_SHORT)
 UNI_CORE_DATA=uprops.icu ucase.icu ubidi.icu
 UNI_CORE_TARGET_DATA=$(UNI_CORE_DATA:%=$(BUILDDIR)/%)
 
@@ -543,6 +547,8 @@ $(CFU_FILES): $(ALL_CFU_SOURCE) $(TOOLBINDIR)/gencfu$(EXEEXT) $(DAT_FILES)
 
 ####################################################    CNV
 # CNV FILES
+$(CNV_FILES_SPECIAL) : $(UCM_FILES_SPECIAL) $(TOOLBINDIR)/makeconv$(TOOLEXEEXT) 
+	$(INVOKE) $(TOOLBINDIR)/makeconv --ignore-siso-check -c -d $(BUILDDIR) $(UCMSRCDIR)/$(@F:%.cnv=%.ucm) 
 $(BUILDDIR)/%.cnv: $(UCMSRCDIR)/%.ucm $(TOOLBINDIR)/makeconv$(TOOLEXEEXT)
 	$(INVOKE) $(TOOLBINDIR)/makeconv -c -d $(BUILDDIR) $(UCMSRCDIR)/$(<F)
 
diff --git a/icu4c/source/data/mappings/ucmebcdic.mk b/icu4c/source/data/mappings/ucmebcdic.mk
index f4c0e04267c..be1755ecf66 100644
--- a/icu4c/source/data/mappings/ucmebcdic.mk
+++ b/icu4c/source/data/mappings/ucmebcdic.mk
@@ -1,4 +1,4 @@
-# Copyright (c) 1999-2007, International Business Machines Corporation and
+# Copyright (c) 1999-2010, International Business Machines Corporation and
 # others. All Rights Reserved.
 # A list of EBCDIC UCM's to build
 # ibm-37 and ibm-1047 are already mentioned in makedata.mak and Makefile.in
@@ -25,3 +25,5 @@ ibm-297_P100-1995.ucm ibm-420_X120-1999.ucm ibm-424_P100-1995.ucm\
 ibm-4517_P100-2005.ucm ibm-4899_P100-1998.ucm ibm-4971_P100-1999.ucm\
 ibm-500_P100-1995.ucm ibm-5123_P100-1999.ucm ibm-803_P100-1999.ucm\
 ibm-8482_P100-1999.ucm ibm-9067_X100-2005.ucm ibm-16684_P110-2003.ucm
+
+UCM_SOURCE_EBCDIC_IGNORE_SISO =
\ No newline at end of file
diff --git a/icu4c/source/tools/makeconv/genmbcs.c b/icu4c/source/tools/makeconv/genmbcs.c
index 696ce4fe95c..840438339b8 100644
--- a/icu4c/source/tools/makeconv/genmbcs.c
+++ b/icu4c/source/tools/makeconv/genmbcs.c
@@ -1,7 +1,7 @@
 /*
 *******************************************************************************
 *
-*   Copyright (C) 2000-2009, International Business Machines
+*   Copyright (C) 2000-2010, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
@@ -687,7 +687,7 @@ MBCSAddFromUnicode(MBCSData *mbcsData,
     maxCharLength=mbcsData->ucm->states.maxCharLength;
 
     if( mbcsData->ucm->states.outputType==MBCS_OUTPUT_2_SISO &&
-        (*bytes==0xe || *bytes==0xf)
+        (!IGNORE_SISO_CHECK && (*bytes==0xe || *bytes==0xf))
     ) {
         fprintf(stderr, "error: illegal mapping to SI or SO for SI/SO codepage: U+%04x<->0x%s\n",
             (int)c, printBytes(buffer, bytes, length));
diff --git a/icu4c/source/tools/makeconv/makeconv.c b/icu4c/source/tools/makeconv/makeconv.c
index bdc12e9e20d..86ead4c0fe7 100644
--- a/icu4c/source/tools/makeconv/makeconv.c
+++ b/icu4c/source/tools/makeconv/makeconv.c
@@ -79,6 +79,7 @@ extern const UConverterStaticData * ucnv_converterStaticData[UCNV_NUMBER_OF_SUPP
  */
 UBool VERBOSE = FALSE;
 UBool SMALL = FALSE;
+UBool IGNORE_SISO_CHECK = FALSE;
 
 static void
 createConverter(ConvData *data, const char* converterName, UErrorCode *pErrorCode);
@@ -174,6 +175,7 @@ enum {
     OPT_DESTDIR,
     OPT_VERBOSE,
     OPT_SMALL,
+    OPT_IGNORE_SISO_CHECK,
     OPT_COUNT
 };
 
@@ -184,7 +186,8 @@ static UOption options[]={
     UOPTION_VERSION,
     UOPTION_DESTDIR,
     UOPTION_VERBOSE,
-    { "small", NULL, NULL, NULL, '\1', UOPT_NO_ARG, 0 }
+    { "small", NULL, NULL, NULL, '\1', UOPT_NO_ARG, 0 },
+    { "ignore-siso-check", NULL, NULL, NULL, '\1', UOPT_NO_ARG, 0 }
 };
 
 int main(int argc, char* argv[])
@@ -236,7 +239,8 @@ int main(int argc, char* argv[])
             "\t      --small       Generate smaller .cnv files. They will be\n"
             "\t                    significantly smaller but may not be compatible with\n"
             "\t                    older versions of ICU and will require heap memory\n"
-            "\t                    allocation when loaded.\n");
+            "\t                    allocation when loaded.\n"
+            "\t      --ignore-siso-check         Use SI/SO other than 0xf/0xe.\n");
         return argc<0 ? U_ILLEGAL_ARGUMENT_ERROR : U_ZERO_ERROR;
     }
 
@@ -253,6 +257,10 @@ int main(int argc, char* argv[])
     VERBOSE = options[OPT_VERBOSE].doesOccur;
     SMALL = options[OPT_SMALL].doesOccur;
 
+    if (options[OPT_IGNORE_SISO_CHECK].doesOccur) {
+        IGNORE_SISO_CHECK = TRUE;
+    }
+
     if (destdir != NULL && *destdir != 0) {
         uprv_strcpy(outFileName, destdir);
         destdirlen = uprv_strlen(destdir);
@@ -579,7 +587,7 @@ readFile(ConvData *data, const char* converterName,
     if(data->ucm->baseName[0]==0) {
         dataIsBase=TRUE;
         baseStates=&data->ucm->states;
-        ucm_processStates(baseStates);
+        ucm_processStates(baseStates, IGNORE_SISO_CHECK);
     } else {
         dataIsBase=FALSE;
         baseStates=NULL;
@@ -782,7 +790,7 @@ createConverter(ConvData *data, const char *converterName, UErrorCode *pErrorCod
                     fprintf(stderr, "       the substitution character byte sequence is illegal in this codepage structure!\n");
                     *pErrorCode=U_INVALID_TABLE_FORMAT;
 
-                } else if(staticData->subChar1!=0 && 1!=ucm_countChars(baseStates, &staticData->subChar1, 1)) {
+                } else if(1!=ucm_countChars(baseStates, &staticData->subChar1, 1)) {
                     fprintf(stderr, "       the subchar1 byte is illegal in this codepage structure!\n");
                     *pErrorCode=U_INVALID_TABLE_FORMAT;
 
diff --git a/icu4c/source/tools/makeconv/makeconv.h b/icu4c/source/tools/makeconv/makeconv.h
index a3c2d375a1b..3cb50706e0e 100644
--- a/icu4c/source/tools/makeconv/makeconv.h
+++ b/icu4c/source/tools/makeconv/makeconv.h
@@ -1,7 +1,7 @@
 /*
 *******************************************************************************
 *
-*   Copyright (C) 2000-2007, International Business Machines
+*   Copyright (C) 2000-2010, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
@@ -25,6 +25,7 @@
 /* exports from makeconv.c */
 U_CFUNC UBool VERBOSE;
 U_CFUNC UBool SMALL;
+U_CFUNC UBool IGNORE_SISO_CHECK;
 
 /* converter table type for writing */
 enum {
diff --git a/icu4c/source/tools/toolutil/ucm.h b/icu4c/source/tools/toolutil/ucm.h
index 6ee13215f2b..20324f54c70 100644
--- a/icu4c/source/tools/toolutil/ucm.h
+++ b/icu4c/source/tools/toolutil/ucm.h
@@ -1,6 +1,6 @@
 /*
  *******************************************************************************
- *   Copyright (C) 2003-2009, International Business Machines
+ *   Copyright (C) 2003-2010, International Business Machines
  *   Corporation and others.  All Rights Reserved.
  *******************************************************************************
  *   file name:  ucm.h
@@ -237,7 +237,7 @@ U_CAPI void U_EXPORT2
 ucm_addState(UCMStates *states, const char *s);
 
 U_CAPI void U_EXPORT2
-ucm_processStates(UCMStates *states);
+ucm_processStates(UCMStates *states, UBool ignoreSISOCheck);
 
 U_CAPI int32_t U_EXPORT2
 ucm_countChars(UCMStates *states,
diff --git a/icu4c/source/tools/toolutil/ucmstate.c b/icu4c/source/tools/toolutil/ucmstate.c
index 393d18b3781..e1adb974a07 100644
--- a/icu4c/source/tools/toolutil/ucmstate.c
+++ b/icu4c/source/tools/toolutil/ucmstate.c
@@ -1,7 +1,7 @@
 /*
 *******************************************************************************
 *
-*   Copyright (C) 2003-2005, International Business Machines
+*   Copyright (C) 2003-2010, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 *******************************************************************************
@@ -421,7 +421,7 @@ sumUpStates(UCMStates *states) {
 }
 
 U_CAPI void U_EXPORT2
-ucm_processStates(UCMStates *states) {
+ucm_processStates(UCMStates *states, UBool ignoreSISOCheck) {
     int32_t entry, state, cell, count;
 
     if(states->conversionType==UCNV_UNSUPPORTED_CONVERTER) {
@@ -557,10 +557,11 @@ ucm_processStates(UCMStates *states) {
             exit(U_INVALID_TABLE_FORMAT);
         }
         /* are the SI/SO all in the right places? */
-        if( states->stateTable[0][0xe]==MBCS_ENTRY_FINAL(1, MBCS_STATE_CHANGE_ONLY, 0) &&
+        if( ignoreSISOCheck ||
+           (states->stateTable[0][0xe]==MBCS_ENTRY_FINAL(1, MBCS_STATE_CHANGE_ONLY, 0) &&
             states->stateTable[0][0xf]==MBCS_ENTRY_FINAL(0, MBCS_STATE_CHANGE_ONLY, 0) &&
             states->stateTable[1][0xe]==MBCS_ENTRY_FINAL(1, MBCS_STATE_CHANGE_ONLY, 0) &&
-            states->stateTable[1][0xf]==MBCS_ENTRY_FINAL(0, MBCS_STATE_CHANGE_ONLY, 0)
+            states->stateTable[1][0xf]==MBCS_ENTRY_FINAL(0, MBCS_STATE_CHANGE_ONLY, 0))
         ) {
             states->outputType=MBCS_OUTPUT_2_SISO;
         } else {