diff --git a/Mods/Display.Mod b/Mods/Display.Mod
index b23b42d..33acf60 100644
--- a/Mods/Display.Mod
+++ b/Mods/Display.Mod
@@ -1,4 +1,4 @@
-MODULE Display;  (*NW 5.11.2013*)
+MODULE Display;  (*NW 5.11.2013 / 17.1.2019*)
 (* Adapted for a customizable framebuffer size -- see git history *)
 
   IMPORT SYSTEM;
@@ -52,7 +52,7 @@ MODULE Display;  (*NW 5.11.2013*)
         END;
         INC(a1, Span)
       END
-    ELSE
+    ELSIF ar > al THEN
       left := {(x MOD 32) .. 31}; right := {0 .. ((x+w-1) MOD 32)};
       a0 := al;
       FOR i := 1 TO h DO
@@ -77,11 +77,11 @@ MODULE Display;  (*NW 5.11.2013*)
 
   PROCEDURE CopyPattern*(col, patadr, x, y, mode: INTEGER);  (*only for modes = paint, invert*)
     VAR a0, pwd, i: INTEGER;
-      w, h, pbt: BYTE; pix: SET;
+      w, h, pbt: BYTE; pix, mask: SET;
   BEGIN SYSTEM.GET(patadr, w); SYSTEM.GET(patadr+1, h); INC(patadr, 2);
-    a0 := base + (x DIV 32)*4 + y*Span;
+    a0 := base + (x DIV 32)*4 + y*Span; x := x MOD 32; mask := SYSTEM.VAL(SET, ASR(7FFFFFFFH, 31-x));
     FOR i := 1 TO h DO
-      (*build pattern line; w < 32*)
+      (*build pattern line; w <= 32*)
       SYSTEM.GET(patadr, pbt); INC(patadr); pwd := pbt;
       IF w > 8 THEN SYSTEM.GET(patadr, pbt); INC(patadr); pwd := pbt*100H + pwd;
         IF w > 16 THEN SYSTEM.GET(patadr, pbt); INC(patadr); pwd := pbt*10000H + pwd;
@@ -89,13 +89,13 @@ MODULE Display;  (*NW 5.11.2013*)
         END
       END ;
       SYSTEM.GET(a0, pix);
-      IF mode = invert THEN SYSTEM.PUT(a0, SYSTEM.VAL(SET, LSL(pwd, x MOD 32)) / pix)
-      ELSE SYSTEM.PUT(a0, SYSTEM.VAL(SET, LSL(pwd, x MOD 32)) + pix)
+      IF mode = invert THEN SYSTEM.PUT(a0, SYSTEM.VAL(SET, LSL(pwd, x)) / pix)
+      ELSE SYSTEM.PUT(a0, SYSTEM.VAL(SET, LSL(pwd, x)) + pix)
       END ;
-      IF (x MOD 32) + w > 32 THEN (*spill over*)
+      IF x + w > 32 THEN (*spill over*)
         SYSTEM.GET(a0+4, pix);
-        IF mode = invert THEN SYSTEM.PUT(a0+4, SYSTEM.VAL(SET, ASR(pwd, -(x MOD 32))) / pix)
-        ELSE SYSTEM.PUT(a0+4, SYSTEM.VAL(SET, ASR(pwd, -(x MOD 32))) + pix)
+        IF mode = invert THEN SYSTEM.PUT(a0+4, SYSTEM.VAL(SET, ASR(pwd, -x)) * mask/ pix)
+        ELSE SYSTEM.PUT(a0+4, SYSTEM.VAL(SET, ASR(pwd, -x)) * mask+ pix)
         END
       END;
       INC(a0, Span)
@@ -175,7 +175,7 @@ MODULE Display;  (*NW 5.11.2013*)
         IF pta0 = pta1 THEN pta0 := patadr+4 END;
         INC(a1, Span);
       END
-    ELSE
+    ELSIF ar > al THEN
       left := {(x MOD 32) .. 31}; right := {0 .. ((x+w-1) MOD 32)};
       a0 := al;
       FOR i := 1 TO h DO