Fix BGSCREEN

SMILEBASIC/bg.d

@@ -136,8 +136,8 @@ class BG
     void screen(int w, int h)
     {
         rot = 0;
-        scalex = 0;
-        scaley = 0;
+        scalex = 1;
+        scaley = 1;
         homex = 0;
         homey = 0;
         chipWidth = 16;