diff --git a/elaborate.cc b/elaborate.cc
index c1df62da6..945c0d167 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -687,16 +687,15 @@ void PGBuiltin::elaborate(Design*des, NetScope*scope) const
 		  cur[idx]->attribute(attrib_list[adx].key,
 				      attrib_list[adx].val);
 
-	      /* The logic devices have some uniform processing. Then
-	         all may have output delays and output drive strength. */
-	    if (NetLogic*log = dynamic_cast<NetLogic*> (cur[idx])) {
-		  log->rise_time(rise_time);
-		  log->fall_time(fall_time);
-		  log->decay_time(decay_time);
+	      /* Set the delays and drive strength for all built in gates.
+	         We still need to add checks to verify that the delays and
+	         strength are consistent with the gates definition. */
+	    cur[idx]->rise_time(rise_time);
+	    cur[idx]->fall_time(fall_time);
+	    cur[idx]->decay_time(decay_time);
 
-		  log->pin(0).drive0(strength0());
-		  log->pin(0).drive1(strength1());
-	    }
+	    cur[idx]->pin(0).drive0(strength0());
+	    cur[idx]->pin(0).drive1(strength1());
 
 	    cur[idx]->set_line(*this);
 	    des->add_node(cur[idx]);
diff --git a/ivl.def b/ivl.def
index ddb57b0a1..1fd54e66e 100644
--- a/ivl.def
+++ b/ivl.def
@@ -255,6 +255,7 @@ ivl_stmt_sub_stmt
 ivl_switch_a
 ivl_switch_b
 ivl_switch_basename
+ivl_switch_delay
 ivl_switch_enable
 ivl_switch_file
 ivl_switch_island
diff --git a/ivl_target.h b/ivl_target.h
index 720dfc3a3..68cf57d61 100644
--- a/ivl_target.h
+++ b/ivl_target.h
@@ -2039,6 +2039,7 @@ extern ivl_island_t ivl_switch_island(ivl_switch_t net);
 extern unsigned ivl_switch_width(ivl_switch_t net);
 extern unsigned ivl_switch_part(ivl_switch_t net);
 extern unsigned ivl_switch_offset(ivl_switch_t net);
+extern ivl_expr_t ivl_switch_delay(ivl_switch_t net, unsigned transition);
 
 /* Not implemented yet
 extern unsigned        ivl_switch_attr_cnt(ivl_switch_t net);
diff --git a/t-dll-api.cc b/t-dll-api.cc
index c9e8adbc4..a2dd1c157 100644
--- a/t-dll-api.cc
+++ b/t-dll-api.cc
@@ -564,7 +564,7 @@ extern "C" ivl_variable_type_t ivl_expr_value(ivl_expr_t net)
 
 extern "C" unsigned ivl_expr_width(ivl_expr_t net)
 {
-      assert(net);
+//      assert(net);
       return net->width_;
 }
 
@@ -2451,6 +2451,12 @@ extern "C" unsigned ivl_switch_offset(ivl_switch_t net)
       return net->offset;
 }
 
+extern "C" ivl_expr_t ivl_switch_delay(ivl_switch_t net, unsigned transition)
+{
+      assert(transition < 3);
+      return net->delay[transition];
+}
+
 extern "C" const char* ivl_switch_file(ivl_switch_t net)
 {
       return net->file;
diff --git a/t-dll.cc b/t-dll.cc
index 23721efa4..e4448d69b 100644
--- a/t-dll.cc
+++ b/t-dll.cc
@@ -650,12 +650,11 @@ void dll_target::logic_attributes(struct ivl_net_logic_s *obj,
       obj->attr  = fill_in_attributes(net);
 }
 
-void dll_target::make_logic_delays_(struct ivl_net_logic_s*obj,
-				    const NetObj*net)
+void dll_target::make_delays_(ivl_expr_t*delay, const NetObj*net)
 {
-      obj->delay[0] = 0;
-      obj->delay[1] = 0;
-      obj->delay[2] = 0;
+      delay[0] = 0;
+      delay[1] = 0;
+      delay[2] = 0;
 
 	/* Translate delay expressions to ivl_target form. Try to
 	   preserve pointer equality, not as a rule but to save on
@@ -663,105 +662,53 @@ void dll_target::make_logic_delays_(struct ivl_net_logic_s*obj,
       if (net->rise_time()) {
 	    expr_ = 0;
 	    net->rise_time()->expr_scan(this);
-	    obj->delay[0] = expr_;
+	    delay[0] = expr_;
 	    expr_ = 0;
       }
       if (net->fall_time()) {
 	    if (net->fall_time() == net->rise_time()) {
-		  obj->delay[1] = obj->delay[0];
+		  delay[1] = delay[0];
 	    } else {
 		  expr_ = 0;
 		  net->fall_time()->expr_scan(this);
-		  obj->delay[1] = expr_;
+		  delay[1] = expr_;
 		  expr_ = 0;
 	    }
       }
       if (net->decay_time()) {
 	    if (net->decay_time() == net->rise_time()) {
-		  obj->delay[2] = obj->delay[0];
+		  delay[2] = delay[0];
 	    } else {
 		  expr_ = 0;
 		  net->decay_time()->expr_scan(this);
-		  obj->delay[2] = expr_;
+		  delay[2] = expr_;
 		  expr_ = 0;
 	    }
       }
 }
 
+void dll_target::make_logic_delays_(struct ivl_net_logic_s*obj,
+                                    const NetObj*net)
+{
+      make_delays_(obj->delay, net);
+}
+
+void dll_target::make_switch_delays_(struct ivl_switch_s*obj,
+                                    const NetObj*net)
+{
+      make_delays_(obj->delay, net);
+}
+
 void dll_target::make_lpm_delays_(struct ivl_lpm_s*obj,
 				  const NetObj*net)
 {
-      obj->delay[0] = 0;
-      obj->delay[1] = 0;
-      obj->delay[2] = 0;
-
-	/* Translate delay expressions to ivl_target form. Try to
-	   preserve pointer equality, not as a rule but to save on
-	   expression trees. */
-      if (net->rise_time()) {
-	    expr_ = 0;
-	    net->rise_time()->expr_scan(this);
-	    obj->delay[0] = expr_;
-	    expr_ = 0;
-      }
-      if (net->fall_time()) {
-	    if (net->fall_time() == net->rise_time()) {
-		  obj->delay[1] = obj->delay[0];
-	    } else {
-		  expr_ = 0;
-		  net->fall_time()->expr_scan(this);
-		  obj->delay[1] = expr_;
-		  expr_ = 0;
-	    }
-      }
-      if (net->decay_time()) {
-	    if (net->decay_time() == net->rise_time()) {
-		  obj->delay[2] = obj->delay[0];
-	    } else {
-		  expr_ = 0;
-		  net->decay_time()->expr_scan(this);
-		  obj->delay[2] = expr_;
-		  expr_ = 0;
-	    }
-      }
+      make_delays_(obj->delay, net);
 }
 
 void dll_target::make_const_delays_(struct ivl_net_const_s*obj,
 				    const NetObj*net)
 {
-      obj->delay[0] = 0;
-      obj->delay[1] = 0;
-      obj->delay[2] = 0;
-
-	/* Translate delay expressions to ivl_target form. Try to
-	   preserve pointer equality, not as a rule but to save on
-	   expression trees. */
-      if (net->rise_time()) {
-	    expr_ = 0;
-	    net->rise_time()->expr_scan(this);
-	    obj->delay[0] = expr_;
-	    expr_ = 0;
-      }
-      if (net->fall_time()) {
-	    if (net->fall_time() == net->rise_time()) {
-		  obj->delay[1] = obj->delay[0];
-	    } else {
-		  expr_ = 0;
-		  net->fall_time()->expr_scan(this);
-		  obj->delay[1] = expr_;
-		  expr_ = 0;
-	    }
-      }
-      if (net->decay_time()) {
-	    if (net->decay_time() == net->rise_time()) {
-		  obj->delay[2] = obj->delay[0];
-	    } else {
-		  expr_ = 0;
-		  net->decay_time()->expr_scan(this);
-		  obj->delay[2] = expr_;
-		  expr_ = 0;
-	    }
-      }
+      make_delays_(obj->delay, net);
 }
 
 bool dll_target::branch(const NetBranch*net)
@@ -1026,6 +973,7 @@ bool dll_target::tran(const NetTran*net)
       obj->lineno = net->get_lineno();
 
       switch_attributes(obj, net);
+      make_switch_delays_(obj, net);
       scope_add_switch(obj->scope, obj);
 
       return true;
diff --git a/t-dll.h b/t-dll.h
index ab7670840..9625650c5 100644
--- a/t-dll.h
+++ b/t-dll.h
@@ -1,7 +1,7 @@
 #ifndef __t_dll_H
 #define __t_dll_H
 /*
- * Copyright (c) 2000-2009 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 2000-2010 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -165,7 +165,9 @@ struct dll_target  : public target_t, public expr_scan_t {
       void sub_off_from_expr_(long);
       void mul_expr_by_const_(long);
 
+      void make_delays_(ivl_expr_t*delay, const NetObj*net);
       void make_logic_delays_(struct ivl_net_logic_s*obj, const NetObj*net);
+      void make_switch_delays_(struct ivl_switch_s*obj, const NetObj*net);
       void make_lpm_delays_(struct ivl_lpm_s*obj, const NetObj*net);
       void make_const_delays_(struct ivl_net_const_s*obj, const NetObj*net);
       void make_scope_parameters(ivl_scope_t scope, const NetScope*net);
@@ -479,6 +481,8 @@ struct ivl_switch_s {
       struct ivl_attribute_s*attr;
       unsigned nattr;
 
+      ivl_expr_t delay[3];
+
       ivl_nexus_t pins[3];
       perm_string file;
       unsigned lineno;
diff --git a/tgt-vvp/draw_switch.c b/tgt-vvp/draw_switch.c
index 732fd0cf4..a7da8ff66 100644
--- a/tgt-vvp/draw_switch.c
+++ b/tgt-vvp/draw_switch.c
@@ -34,6 +34,23 @@ void draw_switch_in_scope(ivl_switch_t sw)
       ivl_nexus_t nex_a, nex_b, enable;
       const char*str_a, *str_b, *str_e;
 
+      ivl_expr_t rise_exp = ivl_switch_delay(sw, 0);
+      ivl_expr_t fall_exp = ivl_switch_delay(sw, 1);
+
+	/* We do not support tran delays. */
+      if ((rise_exp || fall_exp) &&
+          (!number_is_immediate(rise_exp, 64, 0) ||
+           number_is_unknown(rise_exp) ||
+           (get_number_immediate(rise_exp) != 0) ||
+           !number_is_immediate(fall_exp, 64, 0) ||
+           number_is_unknown(fall_exp) ||
+           (get_number_immediate(rise_exp) != 0))) {
+	    fprintf(stderr, "%s:%u: sorry: tranif gates with a delay are not "
+	                    "currently support.\n",
+	                    ivl_switch_file(sw), ivl_switch_lineno(sw));
+	    exit(1);
+      }
+
       island = ivl_switch_island(sw);
       if (ivl_island_flag_test(island, 0) == 0)
 	    draw_tran_island(island);
@@ -68,8 +85,9 @@ void draw_switch_in_scope(ivl_switch_t sw)
 	    break;
 
 	  default:
-	    fprintf(stderr, "%s:%u: sorry: vvp target does not support switch modeling.\n",
-		    ivl_switch_file(sw), ivl_switch_lineno(sw));
+	    fprintf(stderr, "%s:%u: sorry: resistive switch modeling is not "
+	                    "currently supported.\n",
+		            ivl_switch_file(sw), ivl_switch_lineno(sw));
 	    vvp_errors += 1;
 	    return;
       }