diff --git a/libsrc/nes/_scrsize.s b/libsrc/nes/_scrsize.s
index 4de722e64..8ed7e6f1f 100644
--- a/libsrc/nes/_scrsize.s
+++ b/libsrc/nes/_scrsize.s
@@ -11,8 +11,8 @@
 
 .proc   screensize
 
-        ldx     #screenrows
-        ldy     #charsperline
+        ldx     #charsperline
+        ldy     #screenrows
         rts
 
 .endproc
diff --git a/libsrc/nes/nes.inc b/libsrc/nes/nes.inc
index aaba4fca7..1ee5ebc8f 100644
--- a/libsrc/nes/nes.inc
+++ b/libsrc/nes/nes.inc
@@ -26,7 +26,7 @@ ppuhi           = $74
 ppulo           = $75
 ppuval          = $76
 
-screenrows 	= (32-4)
+screenrows 	= (30-1)
 charsperline    = 32
 xsize           = charsperline