diff --git a/sw/main.c b/sw/main.c
index ba39470..4f894d8 100644
--- a/sw/main.c
+++ b/sw/main.c
@@ -22,6 +22,30 @@ int main() {
 	cprintf("Enabling Mapper\n");
 	mapper_enable(1);
 
+	cprintf("Writing 0xcccc to 0x4000\n");
+	*(unsigned int*)(0x4000) = 0xcccc;
+
+	cprintf("Writing 0xdddd to 0x5000\n");
+	*(unsigned int*)(0x5000) = 0xdddd;
+
+	cprintf("Mapping %1xxxx to %2xxxx\n", 4, 16);
+	mapper_write(16, 4);
+
+	cprintf("Mapping %1xxxx to %2xxxx\n", 5, 16);
+	mapper_write(16, 5);
+
+	cprintf("Writing 0xa5a5 to 0x4000\n");
+	*(unsigned int*)(0x4000) = 0xa5a5;
+
+	cprintf("Reading from 0x5000: %x\n", *(unsigned int*)(0x5000));
+
+	cprintf("Resetting map\n");
+	mapper_write(4, 4);
+	mapper_write(5, 5);
+
+	cprintf("Reading from 0x4000: %x\n", *(unsigned int*)(0x4000));
+	cprintf("Reading from 0x5000: %x\n", *(unsigned int*)(0x5000));
+
     while (1) {
 
         sw = sw_read();