diff --git a/Module.cc b/Module.cc
index 72b617203..f7a214d7c 100644
--- a/Module.cc
+++ b/Module.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: Module.cc,v 1.15 2001/07/25 03:10:48 steve Exp $"
+#ident "$Id: Module.cc,v 1.16 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -27,14 +27,19 @@
 # include  "PWire.h"
 # include  <assert.h>
 
-Module::Module(const string&name, const svector<Module::port_t*>*pp)
-: name_(name)
+Module::Module(const char*name, const svector<Module::port_t*>*pp)
+: name_(strdup(name))
 {
       if (pp)
 	    ports_ = *pp;
 
 }
 
+Module::~Module()
+{
+      free(name_);
+}
+
 void Module::add_gate(PGate*gate)
 {
       gates_.push_back(gate);
@@ -137,6 +142,9 @@ const list<PProcess*>& Module::get_behaviors() const
 
 /*
  * $Log: Module.cc,v $
+ * Revision 1.16  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.15  2001/07/25 03:10:48  steve
  *  Create a config.h.in file to hold all the config
  *  junk, and support gcc 3.0. (Stephan Boettcher)
diff --git a/Module.h b/Module.h
index 9497abd3f..cc8ef67e6 100644
--- a/Module.h
+++ b/Module.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: Module.h,v 1.21 2000/11/05 06:05:59 steve Exp $"
+#ident "$Id: Module.h,v 1.22 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include  <list>
@@ -58,7 +58,8 @@ class Module {
       };
 
     public:
-      explicit Module(const string&name, const svector<port_t*>*);
+      explicit Module(const char*name, const svector<port_t*>*);
+      ~Module();
 
 
 	/* The module has parameters that are evaluated when the
@@ -88,7 +89,7 @@ class Module {
 	   set by the `timescale directive. */
       int time_unit, time_precision;
 
-      const string&get_name() const { return name_; }
+      const char*mod_name() const { return name_; }
 
       void add_gate(PGate*gate);
 
@@ -122,7 +123,7 @@ class Module {
       bool elaborate_sig(Design*, NetScope*scope) const;
 
     private:
-      const string name_;
+      char* name_;
 
 	/* This is an array of port descriptors, which is in turn a
 	   named array of PEident pointers. */
@@ -142,6 +143,9 @@ class Module {
 
 /*
  * $Log: Module.h,v $
+ * Revision 1.22  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.21  2000/11/05 06:05:59  steve
  *  Handle connectsion to internally unconnected modules (PR#38)
  *
diff --git a/elab_scope.cc b/elab_scope.cc
index d557849c2..61e0b68b3 100644
--- a/elab_scope.cc
+++ b/elab_scope.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_scope.cc,v 1.10 2001/10/09 02:01:04 steve Exp $"
+#ident "$Id: elab_scope.cc,v 1.11 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -134,7 +134,7 @@ bool Module::elaborate_scope(Design*des, NetScope*scope) const
       for (tasks_it_t cur = tasks_.begin()
 		 ; cur != tasks_.end() ;  cur ++ ) {
 
-	    NetScope*task_scope = new NetScope(scope, (*cur).first,
+	    NetScope*task_scope = new NetScope(scope, (*cur).first.c_str(),
 					       NetScope::TASK);
 	    (*cur).second->elaborate_scope(des, task_scope);
       }
@@ -149,7 +149,7 @@ bool Module::elaborate_scope(Design*des, NetScope*scope) const
       for (funcs_it_t cur = funcs_.begin()
 		 ; cur != funcs_.end() ;  cur ++ ) {
 
-	    NetScope*func_scope = new NetScope(scope, (*cur).first,
+	    NetScope*func_scope = new NetScope(scope, (*cur).first.c_str(),
 					       NetScope::FUNC);
 	    (*cur).second->elaborate_scope(des, func_scope);
       }
@@ -197,7 +197,7 @@ void PGModule::elaborate_scope_mod_(Design*des, Module*mod, NetScope*sc) const
 {
       if (get_name() == "") {
 	    cerr << get_line() << ": error: Instantiation of module "
-		 << mod->get_name() << " requires an instance name." << endl;
+		 << mod->mod_name() << " requires an instance name." << endl;
 	    des->errors += 1;
 	    return;
       }
@@ -227,11 +227,11 @@ void PGModule::elaborate_scope_mod_(Design*des, Module*mod, NetScope*sc) const
 	    if (scn->type() != NetScope::MODULE)
 		  continue;
 
-	    if (mod->get_name() != scn->module_name())
+	    if (strcmp(mod->mod_name(), scn->module_name()) != 0)
 		  continue;
 
 	    cerr << get_line() << ": error: You cannot instantiate "
-		 << "module " << mod->get_name() << " within itself." << endl;
+		 << "module " << mod->mod_name() << " within itself." << endl;
 
 	    cerr << get_line() << ":      : The offending instance is "
 		 << sc->name() << "." << get_name() << " within "
@@ -242,8 +242,8 @@ void PGModule::elaborate_scope_mod_(Design*des, Module*mod, NetScope*sc) const
       }
 
 	// Create the new scope as a MODULE with my name.
-      NetScope*my_scope = new NetScope(sc, get_name(), NetScope::MODULE);
-      my_scope->set_module_name(mod->get_name().c_str());
+      NetScope*my_scope = new NetScope(sc, get_name().c_str(), NetScope::MODULE);
+      my_scope->set_module_name(mod->mod_name());
 
 	// Set time units and precision.
       my_scope->time_unit(mod->time_unit);
@@ -349,7 +349,7 @@ void PBlock::elaborate_scope(Design*des, NetScope*scope) const
       NetScope*my_scope = scope;
 
       if (name_ != "") {
-	    my_scope = new NetScope(scope, name_, bl_type_==BL_PAR
+	    my_scope = new NetScope(scope, name_.c_str(), bl_type_==BL_PAR
 				    ? NetScope::FORK_JOIN
 				    : NetScope::BEGIN_END);
       }
@@ -458,6 +458,9 @@ void PWhile::elaborate_scope(Design*des, NetScope*scope) const
 
 /*
  * $Log: elab_scope.cc,v $
+ * Revision 1.11  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.10  2001/10/09 02:01:04  steve
  *  Tasks can have sub-scopes.
  *
diff --git a/elaborate.cc b/elaborate.cc
index 3e52b8e96..e72d9cc49 100644
--- a/elaborate.cc
+++ b/elaborate.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elaborate.cc,v 1.221 2001/10/19 21:53:24 steve Exp $"
+#ident "$Id: elaborate.cc,v 1.222 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -2285,7 +2285,7 @@ struct root_elem {
 
 Design* elaborate(const map<string,Module*>&modules,
 		  const map<string,PUdp*>&primitives,
-		  list<string>roots)
+		  list<const char*>roots)
 {
       svector<root_elem*> root_elems(roots.size());
       bool rc = true;
@@ -2298,7 +2298,7 @@ Design* elaborate(const map<string,Module*>&modules,
       modlist = &modules;
       udplist = &primitives;
 
-      for (list<string>::const_iterator root = roots.begin();
+      for (list<const char*>::const_iterator root = roots.begin();
 	   root != roots.end(); root++) {
 	    // Look for the root module in the list.
 	    map<string,Module*>::const_iterator mod = modules.find(*root);
@@ -2372,6 +2372,9 @@ Design* elaborate(const map<string,Module*>&modules,
 
 /*
  * $Log: elaborate.cc,v $
+ * Revision 1.222  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.221  2001/10/19 21:53:24  steve
  *  Support multiple root modules (Philip Blundell)
  *
diff --git a/expr_synth.cc b/expr_synth.cc
index 2978cfba8..827bb8311 100644
--- a/expr_synth.cc
+++ b/expr_synth.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: expr_synth.cc,v 1.26 2001/08/31 22:59:48 steve Exp $"
+#ident "$Id: expr_synth.cc,v 1.27 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -353,27 +353,36 @@ NetNet* NetEBLogic::synthesize(Design*des)
 
 NetNet* NetEConcat::synthesize(Design*des)
 {
-      NetScope*scope = des->find_root_scope();
-      assert(scope);
-      assert(repeat_ == 1);
+	/* First, synthesize the operands. */
+      NetNet**tmp = new NetNet*[parms_.count()];
+      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1)
+	    tmp[idx] = parms_[idx]->synthesize(des);
 
+      assert(tmp[0]);
+      NetScope*scope = tmp[0]->scope();
+      assert(scope);
+
+	/* Make a NetNet object to carry the output vector. */
       string path = scope->name() + "." + scope->local_symbol();
       NetNet*osig = new NetNet(scope, path, NetNet::IMPLICIT, expr_width());
       osig->local_flag(true);
 
+	/* Connect the output vector to the operands. */
       unsigned obit = 0;
       for (unsigned idx = parms_.count() ;  idx > 0 ;  idx -= 1) {
-	    NetNet*tmp = parms_[idx-1]->synthesize(des);
 
-	    for (unsigned bit = 0 ;  bit < tmp->pin_count() ;  bit += 1) {
-		  connect(osig->pin(obit), tmp->pin(bit));
+	    assert(tmp[idx-1]);
+
+	    for (unsigned bit = 0;  bit < tmp[idx-1]->pin_count(); bit += 1) {
+		  connect(osig->pin(obit), tmp[idx-1]->pin(bit));
 		  obit += 1;
 	    }
 
-	    if (tmp->local_flag() && tmp->get_eref() == 0)
-		  delete tmp;
+	    if (tmp[idx-1]->local_flag() && tmp[idx-1]->get_eref() == 0)
+		  delete tmp[idx-1];
       }
 
+      delete[]tmp;
       return osig;
 }
 
@@ -553,6 +562,9 @@ NetNet* NetESignal::synthesize(Design*des)
 
 /*
  * $Log: expr_synth.cc,v $
+ * Revision 1.27  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.26  2001/08/31 22:59:48  steve
  *  synthesize the special case of compare with 0.
  *
diff --git a/main.cc b/main.cc
index 78c42d5d7..4ccd9e887 100644
--- a/main.cc
+++ b/main.cc
@@ -19,7 +19,7 @@ const char COPYRIGHT[] =
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: main.cc,v 1.48 2001/10/19 21:53:24 steve Exp $"
+#ident "$Id: main.cc,v 1.49 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -102,7 +102,7 @@ static void parm_to_flagmap(const string&flag)
 
 extern Design* elaborate(const map<string,Module*>&modules,
 			 const map<string,PUdp*>&primitives,
-			 list <string>root);
+			 list <const char*>root);
 
 extern void cprop(Design*des);
 extern void synth(Design*des);
@@ -175,7 +175,7 @@ int main(int argc, char*argv[])
       int opt;
       unsigned flag_errors = 0;
       queue<net_func> net_func_queue;
-      list<string> roots;
+      list<const char*> roots;
 
       struct tms cycles[5];
 
@@ -218,7 +218,7 @@ int main(int argc, char*argv[])
 	    parm_to_flagmap(optarg);
 	    break;
 	  case 's':
-	    roots.push_back(string(optarg));
+	    roots.push_back(optarg);
 	    break;
 	  case 'T':
 	    if (strcmp(optarg,"min") == 0) {
@@ -359,10 +359,10 @@ int main(int argc, char*argv[])
 	    }
 
 	    for (mod = modules.begin(); mod != modules.end(); mod++) {
-		  if (mentioned_p[(*mod).second->get_name()] == false) {
+		  if (mentioned_p[(*mod).second->mod_name()] == false) {
 			if (verbose_flag)
-			      cout << " " << (*mod).second->get_name();
-			roots.push_back((*mod).second->get_name());
+			      cout << " " << (*mod).second->mod_name();
+			roots.push_back((*mod).second->mod_name());
 		  }
 	    }
 	    if (verbose_flag)
@@ -455,6 +455,9 @@ int main(int argc, char*argv[])
 
 /*
  * $Log: main.cc,v $
+ * Revision 1.49  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.48  2001/10/19 21:53:24  steve
  *  Support multiple root modules (Philip Blundell)
  *
diff --git a/net_design.cc b/net_design.cc
index 5c89c2f0c..d52100deb 100644
--- a/net_design.cc
+++ b/net_design.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: net_design.cc,v 1.21 2001/10/19 21:53:24 steve Exp $"
+#ident "$Id: net_design.cc,v 1.22 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -77,11 +77,11 @@ unsigned long Design::scale_to_precision(unsigned long val,
       return val;
 }
 
-NetScope* Design::make_root_scope(const string&root)
+NetScope* Design::make_root_scope(const char*root)
 {
       NetScope *root_scope_;
       root_scope_ = new NetScope(0, root, NetScope::MODULE);
-      root_scope_->set_module_name(root.c_str());
+      root_scope_->set_module_name(root);
       root_scopes_.push_back(root_scope_);
       return root_scope_;
 }
@@ -92,12 +92,6 @@ NetScope* Design::find_root_scope()
       return root_scopes_.front();
 }
 
-const NetScope* Design::find_root_scope() const
-{
-      assert(root_scopes_.front());
-      return root_scopes_.front();
-}
-
 list<NetScope*> Design::find_root_scopes()
 {
       return root_scopes_;
@@ -495,6 +489,9 @@ void Design::delete_process(NetProcTop*top)
 
 /*
  * $Log: net_design.cc,v $
+ * Revision 1.22  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.21  2001/10/19 21:53:24  steve
  *  Support multiple root modules (Philip Blundell)
  *
diff --git a/net_scope.cc b/net_scope.cc
index 0bcb7bdff..e53f8f092 100644
--- a/net_scope.cc
+++ b/net_scope.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: net_scope.cc,v 1.13 2001/07/25 03:10:49 steve Exp $"
+#ident "$Id: net_scope.cc,v 1.14 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -34,7 +34,7 @@
  * in question.
  */
 
-NetScope::NetScope(NetScope*up, const string&n, NetScope::TYPE t)
+NetScope::NetScope(NetScope*up, const char*n, NetScope::TYPE t)
 : type_(t), up_(up), sib_(0), sub_(0)
 {
       memories_ = 0;
@@ -63,8 +63,8 @@ NetScope::NetScope(NetScope*up, const string&n, NetScope::TYPE t)
 	    module_name_ = 0;
 	    break;
       }
-      name_ = new char[n.length()+1];
-      strcpy(name_, n.c_str());
+      name_ = new char[strlen(n)+1];
+      strcpy(name_, n);
 }
 
 NetScope::~NetScope()
@@ -371,6 +371,9 @@ string NetScope::local_symbol()
 
 /*
  * $Log: net_scope.cc,v $
+ * Revision 1.14  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.13  2001/07/25 03:10:49  steve
  *  Create a config.h.in file to hold all the config
  *  junk, and support gcc 3.0. (Stephan Boettcher)
diff --git a/netlist.h b/netlist.h
index 89a339a71..ce19be589 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.217 2001/10/19 21:53:24 steve Exp $"
+#ident "$Id: netlist.h,v 1.218 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 /*
@@ -2558,7 +2558,7 @@ class NetScope {
 
     public:
       enum TYPE { MODULE, TASK, FUNC, BEGIN_END, FORK_JOIN };
-      NetScope(NetScope*up, const string&name, TYPE t);
+      NetScope(NetScope*up, const char*name, TYPE t);
       ~NetScope();
 
 	/* Parameters exist within a scope, and these methods allow
@@ -2709,11 +2709,10 @@ class Design {
 
       string get_flag(const string&key) const;
 
-      NetScope* make_root_scope(const string&name);
+      NetScope* make_root_scope(const char*name);
       NetScope* find_root_scope();
       list<NetScope*> find_root_scopes();
 
-      const NetScope* find_root_scope() const;
       const list<NetScope*> find_root_scopes() const;
 
 	/* Attempt to set the precision to the specified value. If the
@@ -2851,6 +2850,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.218  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.217  2001/10/19 21:53:24  steve
  *  Support multiple root modules (Philip Blundell)
  *
diff --git a/pform.cc b/pform.cc
index d58b417e1..93e84a753 100644
--- a/pform.cc
+++ b/pform.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform.cc,v 1.78 2001/07/25 03:10:49 steve Exp $"
+#ident "$Id: pform.cc,v 1.79 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -108,7 +108,7 @@ static unsigned long evaluate_delay(PExpr*delay)
       return pp->value().as_ulong();
 }
 
-void pform_startmodule(const string&name, svector<Module::port_t*>*ports)
+void pform_startmodule(const char*name, svector<Module::port_t*>*ports)
 {
       assert( pform_cur_module == 0 );
 
@@ -126,10 +126,10 @@ void pform_startmodule(const string&name, svector<Module::port_t*>*ports)
       delete ports;
 }
 
-void pform_endmodule(const string&name)
+void pform_endmodule(const char*name)
 {
       assert(pform_cur_module);
-      assert(name == pform_cur_module->get_name());
+      assert(strcmp(name, pform_cur_module->mod_name()) == 0);
       vl_modules[name] = pform_cur_module;
       pform_cur_module = 0;
 }
@@ -1019,6 +1019,9 @@ int pform_parse(const char*path, map<string,Module*>&modules,
 
 /*
  * $Log: pform.cc,v $
+ * Revision 1.79  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.78  2001/07/25 03:10:49  steve
  *  Create a config.h.in file to hold all the config
  *  junk, and support gcc 3.0. (Stephan Boettcher)
diff --git a/pform.h b/pform.h
index 4df816619..9bbff87fb 100644
--- a/pform.h
+++ b/pform.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform.h,v 1.45 2000/12/11 00:31:43 steve Exp $"
+#ident "$Id: pform.h,v 1.46 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -110,8 +110,8 @@ struct lgate {
  * are to apply to the scope of that module. The endmodule causes the
  * pform to close up and finish the named module.
  */
-extern void pform_startmodule(const string&, svector<Module::port_t*>*);
-extern void pform_endmodule(const string&);
+extern void pform_startmodule(const char*, svector<Module::port_t*>*);
+extern void pform_endmodule(const char*);
 
 extern void pform_make_udp(const char*name, list<string>*parms,
 			   svector<PWire*>*decl, list<string>*table,
@@ -202,6 +202,9 @@ extern void pform_dump(ostream&out, Module*mod);
 
 /*
  * $Log: pform.h,v $
+ * Revision 1.46  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.45  2000/12/11 00:31:43  steve
  *  Add support for signed reg variables,
  *  simulate in t-vvm signed comparisons.
diff --git a/xnfio.cc b/xnfio.cc
index aeffd997a..ef15d4fa4 100644
--- a/xnfio.cc
+++ b/xnfio.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: xnfio.cc,v 1.18 2001/07/25 03:10:50 steve Exp $"
+#ident "$Id: xnfio.cc,v 1.19 2001/10/20 05:21:51 steve Exp $"
 #endif
 
 # include "config.h"
@@ -317,7 +317,7 @@ bool xnfio_f::compare_sideb_const(Design*des, NetCompare*dev)
       if (dev->width() > 4)
 	    return false;
 
-      NetScope*scope = des->find_root_scope();
+      NetScope*scope = dev->scope();
 
       verinum side (verinum::V0, dev->width());
 
@@ -367,6 +367,9 @@ void xnfio(Design*des)
 
 /*
  * $Log: xnfio.cc,v $
+ * Revision 1.19  2001/10/20 05:21:51  steve
+ *  Scope/module names are char* instead of string.
+ *
  * Revision 1.18  2001/07/25 03:10:50  steve
  *  Create a config.h.in file to hold all the config
  *  junk, and support gcc 3.0. (Stephan Boettcher)