diff --git a/include/plus4.h b/include/plus4.h
index 14db27970..0178d66af 100644
--- a/include/plus4.h
+++ b/include/plus4.h
@@ -6,10 +6,10 @@
 /*                                                                           */
 /*                                                                           */
 /*                                                                           */
-/* (C) 1998-2002 Ullrich von Bassewitz                                       */
-/*               Wacholderweg 14                                             */
-/*               D-70597 Stuttgart                                           */
-/* EMail:        uz@musoftware.de                                            */
+/* (C) 1998-2006, Ullrich von Bassewitz                                      */
+/*                Römerstrasse 52                                            */
+/*                D-70794 Filderstadt                                        */
+/* EMail:         uz@cc65.org                                                */
 /*                                                                           */
 /*                                                                           */
 /* This software is provided 'as-is', without any expressed or implied       */
@@ -51,6 +51,10 @@
 #include <cbm264.h>
 #endif
 
+/* Define hardware */
+#include <_6551.h>
+#define ACIA    (*(struct __6551*)0xFD00)
+
 
 
 /* End of plus4.h */