diff --git a/src/compiler/OPB.Mod b/src/compiler/OPB.Mod
old mode 100644
new mode 100755
index 84085804..bb7ba725
--- a/src/compiler/OPB.Mod
+++ b/src/compiler/OPB.Mod
@@ -34,6 +34,16 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
     ELSE          node := OPT.NewNode(OPT.Nvar); err(127)
     END ;
     node^.obj := obj; node^.typ := obj^.typ;
+
+    (* Array and record value parameters with copy disabled are readonly *)
+    (*
+    IF (obj.mode = OPT.Var)
+     & (obj.typ.comp IN {OPT.Array, OPT.DynArr})
+     & (obj.typ.sysflag # 0) THEN
+      node.readonly := TRUE;
+    END ;
+    *)
+
     RETURN node
   END NewLeaf;
 
@@ -849,17 +859,6 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
       p, q: OPT.Struct;
   BEGIN
     y := ynode^.typ; f := x^.form; g := y^.form;
-    (*
-    IF OPM.verbose IN OPM.Options THEN
-       OPM.LogWLn; OPM.LogWStr("PROCEDURE CheckAssign"); OPM.LogWLn;
-    END;
-    IF OPM.verbose IN OPM.Options THEN
-       OPM.LogWStr("y.form = "); OPM.LogWNum(y.form, 0); OPM.LogWLn;
-       OPM.LogWStr("f = "); OPM.LogWNum(f, 0); OPM.LogWLn;
-       OPM.LogWStr("g = "); OPM.LogWNum(g, 0); OPM.LogWLn;
-       OPM.LogWStr("ynode.typ.syze = "); OPM.LogWNum(ynode.typ.size, 0); OPM.LogWLn;
-    END;
-    *)
     IF (ynode^.class = OPT.Ntype) OR (ynode^.class = OPT.Nproc) & (f # OPT.ProcTyp) THEN err(126) END ;
     CASE f OF
       OPT.Undef,
@@ -1340,10 +1339,12 @@ MODULE OPB;  (* RC 6.3.89 / 21.2.94 *)  (* object model 17.1.93 *)
   END StFct;
 
   PROCEDURE DynArrParCheck(ftyp, atyp: OPT.Struct; fvarpar: BOOLEAN);
-    VAR f: INTEGER;
+    VAR f, sysflag: INTEGER;
   BEGIN (* ftyp^.comp = OPT.DynArr *)
+    sysflag := ftyp.sysflag;
     f := atyp^.comp; ftyp := ftyp^.BaseTyp; atyp := atyp^.BaseTyp;
-    IF fvarpar & (ftyp = OPT.bytetyp) THEN (* ok, but ... *)
+    IF (fvarpar OR (sysflag # 0)) & (ftyp = OPT.bytetyp) THEN (* ok, but ... *)
+      (* Allow any parameter type, but give warning in verbose mode *)
       IF ~(f IN {OPT.Array, OPT.DynArr}) OR ~((atyp.form IN {OPT.Byte..OPT.Char, OPT.Int}) & (atyp.size = 1)) THEN
         IF OPM.verbose IN OPM.Options THEN err(-301) END
       END