diff --git a/components/tme/romhack/Makefile b/components/tme/romhack/Makefile
new file mode 100644
index 0000000..44488cd
--- /dev/null
+++ b/components/tme/romhack/Makefile
@@ -0,0 +1,7 @@
+OBJS=recalcchs.o
+TARGET=recalcchs
+
+$(TARGET): $(OBJS)
+	$(CC) -o $(TARGET) $(OBJS)
+
+
diff --git a/components/tme/romhack/recalcchs.c b/components/tme/romhack/recalcchs.c
new file mode 100644
index 0000000..c357a27
--- /dev/null
+++ b/components/tme/romhack/recalcchs.c
@@ -0,0 +1,41 @@
+#include "stdio.h"
+#include "stdint.h"
+#include <stdlib.h>
+
+#define MAXROMSZ 3*1024*1024
+
+int main(int argc, char **argv) {
+	FILE *f;
+	int l, x;
+	unsigned int oldchs, newchs;
+	unsigned char rom[MAXROMSZ];
+	if (argc!=2) {
+		printf("Usage: %s mac-rom-image.bin\nRecalculate checksum on modified rom\n");
+		exit(0);
+	}
+
+	f=fopen(argv[1], "r+");
+	if (f<=0) {
+		perror(argv[1]);
+		exit(1);
+	}
+	l=fread(rom, 1, MAXROMSZ, f);
+
+	oldchs=(rom[0]<<24)+(rom[1]<<16)+(rom[2]<<8)+(rom[3]);
+	newchs=0;
+	for (x=4; x<l; x+=2) {
+		newchs+=(rom[x]<<8)+rom[x+1];
+	}
+	printf("ROM size: %X\n", l);
+	printf("Old checksum: %04X\n", oldchs);
+	printf("New checksum: %04X\n", newchs);
+	if (oldchs!=newchs) {
+		rom[0]=newchs>>24;
+		rom[1]=newchs>>16;
+		rom[2]=newchs>>8;
+		rom[3]=newchs>>0;
+		fseek(f, 0, SEEK_SET);
+		fwrite(rom, 4, 1, f);
+	}
+	fclose(f);
+}
\ No newline at end of file