diff --git a/c64/aliases/,aliases_config.s b/c64/aliases/,aliases_config.s
index 6d97e40c..953c5ee7 100644
--- a/c64/aliases/,aliases_config.s
+++ b/c64/aliases/,aliases_config.s
@@ -102,9 +102,9 @@
 
 // Check that memory model and ROM layout configurations is correct
 {
-//#if ROM_LAYOUT_M65 && !CONFIG_CPU_M65_45GS02
-//	.error "Mega65 ROM layout requires CONFIG_CPU_M65_45GS02"
-//#endif
+#if ROM_LAYOUT_M65 && !CONFIG_CPU_M65_45GS02
+	.error "Mega65 ROM layout requires CONFIG_CPU_M65_45GS02"
+#endif
 //#if ROM_LAYOUT_M65 && !CONFIG_MB_MEGA_65
 //	.error "Mega65 ROM layout requires CONFIG_MB_MEGA_65"
 //#endif
diff --git a/c64/kernal/banking/4000.mega65_kernal_1.s b/c64/kernal/banking/4000.mega65_kernal_1.s
index ffaaf370..fbe3311a 100644
--- a/c64/kernal/banking/4000.mega65_kernal_1.s
+++ b/c64/kernal/banking/4000.mega65_kernal_1.s
@@ -1,13 +1,28 @@
-#if (ROM_LAYOUT_M65 && SEGMENT_KERNAL_1)
 
 //
 // Definitions for communication with Mega65 segment KERNAL_1
 //
 
 
-// XXX this is for testing only
+#if (ROM_LAYOUT_M65 && SEGMENT_KERNAL_0)
+
+	// Labels for jumps
+
+
+.label KERNAL_1__TESTROUTINE = $4000
+
+
+#elif (ROM_LAYOUT_M65 && SEGMENT_KERNAL_1)
+
+	// Jumptable (OpenROMs private!)
+
+
+	jmp TESTROUTINE
+
+
+TESTROUTINE:
 
 	rts
 
 
-#endif // ROM layout
+#endif
diff --git a/c64/kernal/banking/mega65_mapping.s b/c64/kernal/banking/mega65_mapping.s
new file mode 100644
index 00000000..d4f037f1
--- /dev/null
+++ b/c64/kernal/banking/mega65_mapping.s
@@ -0,0 +1,51 @@
+#if (ROM_LAYOUT_M65 && SEGMENT_KERNAL_0)
+
+//
+// ROM mapping routines for Mega65
+//
+
+
+map_NORMAL:
+
+	pha
+	phx
+	phy
+	phz
+
+	lda #$00
+	tax
+	tay
+	taz
+
+	// FALLTROUGH
+
+map_end:
+
+	map
+	eom
+
+	plz
+	ply
+	plx
+	pla
+
+	rts
+
+
+map_KERNAL_1:
+
+	pha
+	phx
+	phy
+	phz
+
+	lda #$00
+	tay
+	taz
+
+	ldx #$42    // XXX map 8KB from 0x20000 to 0x4000 - somehow does not seem to work
+
+	bne map_end
+
+
+#endif // ROM layout