diff --git a/defs.h b/defs.h
index 4c44b4649..1a134dc5b 100644
--- a/defs.h
+++ b/defs.h
@@ -91,8 +91,8 @@
 #define PAL16_RED		224
 #define PAL16_GRAY		240
 
-#define SCREEN_WIDTH	1280
-#define SCREEN_HEIGHT	960
+#define SCREEN_WIDTH	640
+#define SCREEN_HEIGHT	480
 
 #define ZOOM_WIDTH		384
 #define ZOOM_HEIGHT		224