diff --git a/Makefile b/Makefile
index fc5883ec..65a602ff 100644
--- a/Makefile
+++ b/Makefile
@@ -203,6 +203,7 @@ SEG_LIST_M65       = $(DIR_M65)/basic.seg_0  \
                      $(DIR_M65)/basic.seg_1  \
                      $(DIR_M65)/dos.seg_1    \
                      $(DIR_M65)/kernal.seg_0 \
+                     $(DIR_M65)/kernal.seg_C \
                      $(DIR_M65)/kernal.seg_1
 
 SEG_LIST_X16       = $(DIR_X16)/basic.seg_0  \
@@ -356,6 +357,8 @@ $(DIR_M65)/basic.seg_1  $(DIR_M65)/BASIC_1_combined.vs  $(DIR_M65)/BASIC_1_combi
     $(TOOL_ASSEMBLER) $(TOOL_BUILD_SEGMENT) $(DEP_BASIC) $(CFG_M65) $(GEN_STR_M65) $(DIR_M65)/KERNAL_0_combined.sym $(DIR_M65)/BASIC_0_combined.sym
 $(DIR_M65)/dos.seg_1    $(DIR_M65)/DOS_1_combined.vs    $(DIR_M65)/DOS_1_combined.sym: \
     $(TOOL_ASSEMBLER) $(TOOL_BUILD_SEGMENT) $(DEP_DOS_M65) $(CFG_M65)
+$(DIR_M65)/kernal.seg_C $(DIR_M65)/KERNAL_C_combined.vs $(DIR_M65)/KERNAL_C_combined.sym: \
+    $(TOOL_ASSEMBLER) $(TOOL_BUILD_SEGMENT) $(DEP_KERNAL) $(CFG_M65) $(GEN_STR_M65) $(DIR_M65)/KERNAL_0_combined.sym
 $(DIR_M65)/kernal.seg_1 $(DIR_M65)/KERNAL_1_combined.vs $(DIR_M65)/KERNAL_1_combined.sym: \
     $(TOOL_ASSEMBLER) $(TOOL_BUILD_SEGMENT) $(DEP_KERNAL) $(CFG_M65) $(GEN_STR_M65) $(DIR_M65)/KERNAL_0_combined.sym
 
@@ -513,6 +516,11 @@ $(DIR_M65)/dos.seg_1 $(DIR_M65)/DOS_1_combined.vs $(DIR_M65)/DOS_1_combined.sym:
 	@rm -f $@* $(DIR_M65)/dos.seg_1 $(DIR_M65)/DOS_1*
 	@$(TOOL_BUILD_SEGMENT) -a ../../$(TOOL_ASSEMBLER) -r M65 -s DOS_1 -i DOS_1-mega65 -o dos.seg_1 -d $(DIR_M65) -l 4000 -h 7fff $(CFG_M65) $(SRCDIR_DOS_M65)
 
+$(DIR_M65)/kernal.seg_C $(DIR_M65)/KERNAL_C_combined.vs $(DIR_M65)/KERNAL_C_combined.sym:
+	@mkdir -p $(DIR_M65)
+	@rm -f $@* $(DIR_M65)/kernal.seg_C $(DIR_M65)/KERNAL_C*
+	@$(TOOL_BUILD_SEGMENT) -a ../../$(TOOL_ASSEMBLER) -r M65 -s KERNAL_C -i KERNAL_C-mega65 -o kernal.seg_C -d $(DIR_M65) -l c000 -h cfff $(CFG_M65) $(GEN_STR_M65) $(SRCDIR_KERNAL) $(GEN_KERNAL)
+
 $(DIR_M65)/kernal.seg_1 $(DIR_M65)/KERNAL_1_combined.vs $(DIR_M65)/KERNAL_1_combined.sym:
 	@mkdir -p $(DIR_M65)
 	@rm -f $@* $(DIR_M65)/kernal.seg_1 $(DIR_M65)/KERNAL_1*
@@ -710,7 +718,7 @@ $(TARGET_M65_x_ORF) $(TARGET_M65_x_PXL): $(SEG_LIST_M65) build/padding_64_KB bui
 	@cat $(DIR_M65)/basic.seg_1          >> $(TARGET_M65_x_ORF)
 	@cat build/chargen_openroms.patched  >> $(TARGET_M65_x_ORF)
 	@cat $(DIR_M65)/basic.seg_0          >> $(TARGET_M65_x_ORF)
-	@cat build/padding_4_KB              >> $(TARGET_M65_x_ORF)
+	@cat $(DIR_M65)/kernal.seg_C         >> $(TARGET_M65_x_ORF)
 	@cat $(TARGET_CHR_ORF)               >> $(TARGET_M65_x_ORF)
 	@cat $(DIR_M65)/kernal.seg_0         >> $(TARGET_M65_x_ORF)
 	@cat build/padding_64_KB             >> $(TARGET_M65_x_ORF)
@@ -725,7 +733,7 @@ $(TARGET_M65_x_ORF) $(TARGET_M65_x_PXL): $(SEG_LIST_M65) build/padding_64_KB bui
 	@cat $(DIR_M65)/basic.seg_1          >> $(TARGET_M65_x_PXL)
 	@cat build/chargen_pxlfont.patched   >> $(TARGET_M65_x_PXL)
 	@cat $(DIR_M65)/basic.seg_0          >> $(TARGET_M65_x_PXL)
-	@cat build/padding_4_KB              >> $(TARGET_M65_x_PXL)
+	@cat $(DIR_M65)/kernal.seg_C         >> $(TARGET_M65_x_PXL)
 	@cat $(TARGET_CHR_PXL)               >> $(TARGET_M65_x_PXL)
 	@cat $(DIR_M65)/kernal.seg_0         >> $(TARGET_M65_x_PXL)
 	@cat build/padding_64_KB             >> $(TARGET_M65_x_PXL)
diff --git a/doc/Development.md b/doc/Development.md
index 2f76bdfd..85d534d9 100644
--- a/doc/Development.md
+++ b/doc/Development.md
@@ -95,7 +95,7 @@ Currently there are 4 ROM layouts defined:
 
 - `STD` - with 2 code segments: `BASIC` (`$A000-$E4D2`, where `$C000-$DFFF` is a skip-gap for RAM and I/O area) and `KERNAL` (`$E4D3 - $FFFF`)
 - `CRT` - where `BASIC` becames `BASIC_0` and `KERNAL` becames `KERNAL_0`, with additional `BASIC`/`KERNAL` segments are placed on the required cartridge image
-- `M65` - where `BASIC` becames `BASIC_0` and `KERNAL` becames `KERNAL_0`, additional segments might be added to the build system in the future; at the moment of writing this document additional 12KB of ROM is defined as `BASIC_1` segment and additional 8KB of ROM is defined as `KERNAL_1` segment
+- `M65` - where `BASIC` becames `BASIC_0` and `KERNAL` becames `KERNAL_0`, additional segments might be added to the build system in the future; at the moment of writing this document additional 12KB of ROM is defined as `BASIC_1` segment, additional 4KB of ROM is defined as `KERNAL_C` segment, and additional 8KB of ROM is defined as `KERNAL_1` segment
 - `X16` - memory layout for the Commander X16 machine
 
 Expect at least one more, `U64`, if the planned additional ROM banks support for Ultimate 64 gets implemented. To check for current ROM layout or code segment use KickAssembler preprocessor defines, like `ROM_LAYOUT_STD`, `SEGMENT_M65_BASIC_0`, `SEGMENT_X16_KERNAL_1`.
diff --git a/src/kernal/board_m65/C000.interop b/src/kernal/board_m65/C000.interop
new file mode 100644
index 00000000..7acd2a6f
--- /dev/null
+++ b/src/kernal/board_m65/C000.interop
@@ -0,0 +1 @@
+This particular address is not for interoperability - we had to choose some fixed location for the extended ROM jumptable, beginning of the mapped memory block is just sane.
diff --git a/src/kernal/board_m65/C000.mega65_vectable_kernal_C.s b/src/kernal/board_m65/C000.mega65_vectable_kernal_C.s
new file mode 100644
index 00000000..d085403f
--- /dev/null
+++ b/src/kernal/board_m65/C000.mega65_vectable_kernal_C.s
@@ -0,0 +1,21 @@
+;; #LAYOUT# M65 KERNAL_0 #TAKE-FLOAT
+;; #LAYOUT# M65 KERNAL_C #TAKE
+;; #LAYOUT# *   *        #IGNORE
+
+;
+; Definitions for communication with MEGA65 segment KERNAL_C from KERNAL_0
+;
+
+
+!ifdef SEGMENT_KERNAL_0 {
+
+	; Label definitions
+
+	!addr VKC__m65_scnkey                = $C000 + 2 * 0
+
+} else {
+
+	; Vector table (Open ROMs private!)
+
+	!word $0000
+}