diff --git a/atari_src/delay.c b/atari_src/delay.c
index 855f1ae..8fd6d97 100644
--- a/atari_src/delay.c
+++ b/atari_src/delay.c
@@ -1,3 +1,13 @@
+/*
+ * mt32-pi-control
+ *
+ * An mt32-pi control program for DOS PCs, Atari ST,
+ * and Amiga computers
+ *
+ * Copyright (C) 2021 Andreas Zdziarstek 
+ *
+ */
+
 #include <osbind.h>
 
 #include "delay.h"
diff --git a/linux_src/delay.c b/linux_src/delay.c
index 5b5f455..c494bcf 100644
--- a/linux_src/delay.c
+++ b/linux_src/delay.c
@@ -1,3 +1,13 @@
+/*
+ * mt32-pi-control
+ *
+ * An mt32-pi control program for DOS PCs, Atari ST,
+ * and Amiga computers
+ *
+ * Copyright (C) 2021 Andreas Zdziarstek 
+ *
+ */
+
 #include <time.h>
 #include <errno.h>