diff --git a/ivl_target.h b/ivl_target.h
index 5710d61ce..5f2f4c2fc 100644
--- a/ivl_target.h
+++ b/ivl_target.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: ivl_target.h,v 1.23 2000/10/25 05:41:24 steve Exp $"
+#ident "$Id: ivl_target.h,v 1.24 2000/10/28 17:55:03 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -135,6 +135,7 @@ typedef struct ivl_statement_s*ivl_statement_t;
 typedef enum ivl_expr_type_e {
       IVL_EX_NONE = 0,
       IVL_EX_BINARY,
+      IVL_EX_CONCAT,
       IVL_EX_NUMBER,
       IVL_EX_SFUNC,
       IVL_EX_SIGNAL,
@@ -523,6 +524,9 @@ _END_DECL
 
 /*
  * $Log: ivl_target.h,v $
+ * Revision 1.24  2000/10/28 17:55:03  steve
+ *  stub for the concat operator.
+ *
  * Revision 1.23  2000/10/25 05:41:24  steve
  *  Get target signal from nexus_ptr.
  *
diff --git a/t-dll-expr.cc b/t-dll-expr.cc
index 4b0489c32..92d2f8a4c 100644
--- a/t-dll-expr.cc
+++ b/t-dll-expr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) & !defined(macintosh)
-#ident "$Id: t-dll-expr.cc,v 1.5 2000/10/05 05:03:01 steve Exp $"
+#ident "$Id: t-dll-expr.cc,v 1.6 2000/10/28 17:55:03 steve Exp $"
 #endif
 
 # include  "t-dll.h"
@@ -55,6 +55,17 @@ void dll_target::expr_binary(const NetEBinary*net)
       expr_->u_.binary_.rig_ = rght;
 }
 
+void dll_target::expr_concat(const NetEConcat*net)
+{
+      assert(expr_ == 0);
+
+      expr_ = new struct ivl_expr_s;
+      assert(expr_);
+
+      expr_->type_ = IVL_EX_CONCAT;
+      expr_->width_= net->expr_width();
+}
+
 void dll_target::expr_const(const NetEConst*net)
 {
       assert(expr_ == 0);
@@ -122,6 +133,9 @@ void dll_target::expr_signal(const NetESignal*net)
 
 /*
  * $Log: t-dll-expr.cc,v $
+ * Revision 1.6  2000/10/28 17:55:03  steve
+ *  stub for the concat operator.
+ *
  * Revision 1.5  2000/10/05 05:03:01  steve
  *  xor and constant devices.
  *
diff --git a/t-dll.h b/t-dll.h
index 1a44a8013..b00bd1d98 100644
--- a/t-dll.h
+++ b/t-dll.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-dll.h,v 1.15 2000/10/21 16:49:45 steve Exp $"
+#ident "$Id: t-dll.h,v 1.16 2000/10/28 17:55:03 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -79,6 +79,7 @@ struct dll_target  : public target_t, public expr_scan_t {
 
       struct ivl_expr_s*expr_;
       void expr_binary(const NetEBinary*);
+      void expr_concat(const NetEConcat*);
       void expr_const(const NetEConst*);
       void expr_sfunc(const NetESFunc*);
       void expr_signal(const NetESignal*);
@@ -310,6 +311,9 @@ struct ivl_statement_s {
 
 /*
  * $Log: t-dll.h,v $
+ * Revision 1.16  2000/10/28 17:55:03  steve
+ *  stub for the concat operator.
+ *
  * Revision 1.15  2000/10/21 16:49:45  steve
  *  Reduce the target entry points to the target_design.
  *
diff --git a/tgt-stub/stub.c b/tgt-stub/stub.c
index 984c533a3..4b843a485 100644
--- a/tgt-stub/stub.c
+++ b/tgt-stub/stub.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: stub.c,v 1.21 2000/10/25 05:41:24 steve Exp $"
+#ident "$Id: stub.c,v 1.22 2000/10/28 17:55:03 steve Exp $"
 #endif
 
 /*
@@ -35,20 +35,31 @@ static FILE*out;
 static void show_expression(ivl_expr_t net, unsigned ind)
 {
       const ivl_expr_type_t code = ivl_expr_type(net);
+      unsigned width = ivl_expr_width(net);
+      const char*sign = ivl_expr_signed(net)? "signed" : "unsigned";
 
       switch (code) {
 
+	  case IVL_EX_BINARY:
+	    fprintf(out, "%*s<\"%c\" width=%u, %s>\n", ind, "",
+		    ivl_expr_opcode(net), width, sign);
+	    show_expression(ivl_expr_oper1(net), ind+3);
+	    show_expression(ivl_expr_oper2(net), ind+3);
+	    break;
+
+	  case IVL_EX_CONCAT:
+	    fprintf(out, "%*s<concat width=%u, %s>\n", ind, "", width, sign);
+	    break;
+
 	  case IVL_EX_NUMBER: {
 		const char*bits = ivl_expr_bits(net);
-		unsigned width = ivl_expr_width(net);
 		unsigned idx;
 
 		fprintf(out, "%*s<number=%u'b", ind, "", width);
 		for (idx = width ;  idx > 0 ;  idx -= 1)
 		      fprintf(out, "%c", bits[idx-1]);
 
-		fprintf(out, ", %s>\n", ivl_expr_signed(net)? "signed"
-			: "unsigned");
+		fprintf(out, ", %s>\n", sign);
 		break;
 	  }
 
@@ -63,8 +74,8 @@ static void show_expression(ivl_expr_t net, unsigned ind)
 	    break;
 
 	  case IVL_EX_SIGNAL:
-	    fprintf(out, "%*s<signal=%s, width=%u>\n", ind, "",
-		    ivl_expr_name(net), ivl_expr_width(net));
+	    fprintf(out, "%*s<signal=%s, width=%u, %s>\n", ind, "",
+		    ivl_expr_name(net), width, sign);
 	    break;
 
 	  default:
@@ -325,6 +336,9 @@ DECLARE_CYGWIN_DLL(DllMain);
 
 /*
  * $Log: stub.c,v $
+ * Revision 1.22  2000/10/28 17:55:03  steve
+ *  stub for the concat operator.
+ *
  * Revision 1.21  2000/10/25 05:41:24  steve
  *  Get target signal from nexus_ptr.
  *