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..c05c6d2
--- /dev/null
+++ b/z80screentest
@@ -0,0 +1 @@
+Subproject commit c05c6d213314152debe13a626ea21ff7dfd66023