diff --git a/arch/z80/src/Makefile.sdcc b/arch/z80/src/Makefile.sdcc
index 51751be8514..895ecc4baef 100644
--- a/arch/z80/src/Makefile.sdcc
+++ b/arch/z80/src/Makefile.sdcc
@@ -207,8 +207,13 @@ endif
 
 nuttx$(EXEEXT): pass1.ihx nuttx.ihx
 	@rm -f pass1.*
-	@packihx nuttx.ihx > $(TOPDIR)/nuttx$(EXEEXT)
 	@cp -f nuttx.map $(TOPDIR)/.
+ifeq ($(EXEEXT),.CMD)
+	sed s/:00000001FF/:00520001AD/ nuttx.ihx | \
+	hex2cmd > $(TOPDIR)/NUTTX.CMD
+else
+	@packihx nuttx.ihx > $(TOPDIR)/nuttx$(EXEEXT)
+endif
 
 # Build dependencies
 
diff --git a/configs/xtrs/nsh/Make.defs b/configs/xtrs/nsh/Make.defs
index 92d1e373895..1c582dffb21 100644
--- a/configs/xtrs/nsh/Make.defs
+++ b/configs/xtrs/nsh/Make.defs
@@ -65,7 +65,7 @@ SDCCLIB			= z80.lib
 ASMEXT			= .asm
 OBJEXT			= .o
 LIBEXT			= .lib
-EXEEXT			= .hex
+EXEEXT			= .CMD
 
 define COMPILE
 	@echo "CC: $1"
diff --git a/configs/xtrs/ostest/Make.defs b/configs/xtrs/ostest/Make.defs
index 48bae87439a..47de3f0ee80 100644
--- a/configs/xtrs/ostest/Make.defs
+++ b/configs/xtrs/ostest/Make.defs
@@ -65,7 +65,7 @@ SDCCLIB			= z80.lib
 ASMEXT			= .asm
 OBJEXT			= .o
 LIBEXT			= .lib
-EXEEXT			= .hex
+EXEEXT			= .CMD
 
 define COMPILE
 	@echo "CC: $1"
diff --git a/configs/xtrs/pashello/Make.defs b/configs/xtrs/pashello/Make.defs
index 48bae87439a..47de3f0ee80 100644
--- a/configs/xtrs/pashello/Make.defs
+++ b/configs/xtrs/pashello/Make.defs
@@ -65,7 +65,7 @@ SDCCLIB			= z80.lib
 ASMEXT			= .asm
 OBJEXT			= .o
 LIBEXT			= .lib
-EXEEXT			= .hex
+EXEEXT			= .CMD
 
 define COMPILE
 	@echo "CC: $1"