diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..1062674
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "z80screentest"]
+	path = z80screentest
+	url = https://github.com/amberisvibin/z80screentest
diff --git a/z80screentest b/z80screentest
new file mode 160000
index 0000000..185e5ee
--- /dev/null
+++ b/z80screentest
@@ -0,0 +1 @@
+Subproject commit 185e5ee1199d4e7cd34ecab573d5044a2b6f6d65