diff --git a/software/build.sh b/software/build.sh
index 36aed8c..83e028a 100755
--- a/software/build.sh
+++ b/software/build.sh
@@ -2,6 +2,12 @@
 
 ROOT_DIR=/dvlp/Projects/dev/github/MZ80A_RFS/
 SW_DIR=${ROO_DIR}/software
+PROCESS_MZF_FILES=0
+if [ "x$1" = '-m' ]; then
+	PROCESS_MZF_FILES=1
+fi
+
+
 (
 cd $SW_DIR
 tools/assemble_rfs.sh
@@ -20,10 +26,13 @@ if [ $? != 0 ]; then
 	exit 1
 fi
 
-tools/processMZFfiles.sh
-if [ $? != 0 ]; then
-	echo "Failed to process MZF files into sectored variants...."
-	exit 1
+# Only needed if the program source tree changes, takes too long to run on every build!
+if [ ${PROCESS_MFZ_FILES} != 1 ]; then
+	tools/processMZFfiles.sh
+	if [ $? != 0 ]; then
+		echo "Failed to process MZF files into sectored variants...."
+		exit 1
+	fi
 fi
 tools/make_roms.sh
 if [ $? != 0 ]; then
diff --git a/software/roms/MROM_256.bin b/software/roms/MROM_256.bin
index 64bc7ce..2506f6a 100644
Binary files a/software/roms/MROM_256.bin and b/software/roms/MROM_256.bin differ
diff --git a/software/roms/USER_ROM_256.bin b/software/roms/USER_ROM_256.bin
index 759bc77..a1b360a 100644
Binary files a/software/roms/USER_ROM_256.bin and b/software/roms/USER_ROM_256.bin differ
diff --git a/software/tools/make_sdcard.sh b/software/tools/make_sdcard.sh
index 0b53f3c..0b8f1fa 100755
--- a/software/tools/make_sdcard.sh
+++ b/software/tools/make_sdcard.sh
@@ -13,7 +13,7 @@
 ## Copyright:       (c) 2020 Philip Smart <philip.smart@net2net.org>
 ##
 ## History:         March 2020   - Initial script written.
-##                  March 2021   - Updated the file list.
+##                  March 2021   - Updated the file list and filter out files stored in the ROM Drives.
 ##
 #########################################################################################################
 ## This source file is free software: you can redistribute it and#or modify
@@ -424,7 +424,7 @@ IFS=":"; for f in ${RFS_INCLUDE}
 do
     # Use the ROM File List to filter out duplicates.
     #
-    grep `basename "${f}" .MZF` ${ROM_LIST_FILE} l > /dev/null
+    grep `basename "${f}" .MZF` ${ROM_LIST_FILE} > /dev/null
     if [ $? = 1 ]; then
 	    echo "Adding ${f}..."
 	    ${SDTOOL} --image ${RFS_IMAGE_FILE} --add ${f}