diff --git a/PExpr.cc b/PExpr.cc
index 3aa9bd86b..0680defb1 100644
--- a/PExpr.cc
+++ b/PExpr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: PExpr.cc,v 1.16 2000/04/12 04:23:57 steve Exp $"
+#ident "$Id: PExpr.cc,v 1.17 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 # include  "PExpr.h"
@@ -64,11 +64,16 @@ bool PEBinary::is_constant(Module*mod) const
       return left_->is_constant(mod) && right_->is_constant(mod);
 }
 
-PECallFunction::PECallFunction(const string &n, const svector<PExpr *> &parms) 
+PECallFunction::PECallFunction(const char*n, const svector<PExpr *> &parms) 
 : name_(n), parms_(parms)
 {
 }
 
+PECallFunction::PECallFunction(const char*n) 
+: name_(n)
+{
+}
+
 PECallFunction::~PECallFunction()
 {
 }
@@ -207,6 +212,10 @@ bool PETernary::is_constant(Module*) const
 
 /*
  * $Log: PExpr.cc,v $
+ * Revision 1.17  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.16  2000/04/12 04:23:57  steve
  *  Named events really should be expressed with PEIdent
  *  objects in the pform,
diff --git a/PExpr.h b/PExpr.h
index 06fc51dff..ab0bf5877 100644
--- a/PExpr.h
+++ b/PExpr.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: PExpr.h,v 1.35 2000/04/12 04:23:57 steve Exp $"
+#ident "$Id: PExpr.h,v 1.36 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 # include  <string>
@@ -339,25 +339,31 @@ class PETernary : public PExpr {
 };
 
 /*
- * This class represents a parsed call to a function.
+ * This class represents a parsed call to a function, including calls
+ * to system functions.
  */
 class PECallFunction : public PExpr {
     public:
-      explicit PECallFunction(const string &n, const svector<PExpr *> &parms);
+      explicit PECallFunction(const char*n, const svector<PExpr *> &parms);
+      explicit PECallFunction(const char*n);
       ~PECallFunction();
 
       virtual void dump(ostream &) const;
-      virtual NetExpr*elaborate_expr(Design*des, NetScope*) const;
+      virtual NetExpr*elaborate_expr(Design*des, NetScope*scope) const;
 
     private:
       string name_;
       svector<PExpr *> parms_;
 
-      NetESFunc* elaborate_sfunc_(Design*des, NetScope*scope) const;
+      NetExpr* elaborate_sfunc_(Design*des, NetScope*scope) const;
 };
 
 /*
  * $Log: PExpr.h,v $
+ * Revision 1.36  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.35  2000/04/12 04:23:57  steve
  *  Named events really should be expressed with PEIdent
  *  objects in the pform,
diff --git a/design_dump.cc b/design_dump.cc
index 46e44b7b1..bc3fc4818 100644
--- a/design_dump.cc
+++ b/design_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: design_dump.cc,v 1.81 2000/05/02 03:13:30 steve Exp $"
+#ident "$Id: design_dump.cc,v 1.82 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 /*
@@ -822,6 +822,11 @@ void NetEScope::dump(ostream&o) const
       o << "<scope=" << scope_->name() << ">";
 }
 
+void NetESFunc::dump(ostream&o) const
+{
+      o << name_ << "()";
+}
+
 void NetESignal::dump(ostream&o) const
 {
       o << name();
@@ -924,6 +929,10 @@ void Design::dump(ostream&o) const
 
 /*
  * $Log: design_dump.cc,v $
+ * Revision 1.82  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.81  2000/05/02 03:13:30  steve
  *  Move memories to the NetScope object.
  *
diff --git a/dup_expr.cc b/dup_expr.cc
index cb017412e..3d5191d75 100644
--- a/dup_expr.cc
+++ b/dup_expr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: dup_expr.cc,v 1.2 2000/02/23 02:56:54 steve Exp $"
+#ident "$Id: dup_expr.cc,v 1.3 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -29,8 +29,17 @@ NetEScope* NetEScope::dup_expr() const
       return 0;
 }
 
+NetESFunc* NetESFunc::dup_expr() const
+{
+      return new NetESFunc(name_, expr_width());
+}
+
 /*
  * $Log: dup_expr.cc,v $
+ * Revision 1.3  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.2  2000/02/23 02:56:54  steve
  *  Macintosh compilers do not support ident.
  *
diff --git a/elab_expr.cc b/elab_expr.cc
index 845816abd..98ad43576 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_expr.cc,v 1.23 2000/05/02 03:13:30 steve Exp $"
+#ident "$Id: elab_expr.cc,v 1.24 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 
@@ -142,10 +142,23 @@ NetEBinary* PEBinary::elaborate_expr_base_(Design*des,
       return tmp;
 }
 
-NetESFunc* PECallFunction::elaborate_sfunc_(Design*des, NetScope*) const
+NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*) const
 {
-      cerr << get_line() << ": sorry: system functions not supported."
-	   << endl;
+      if (parms_.count() > 0) {
+	    cerr << get_line() << ": sorry: system function "
+		  "parmaeters not supported." << endl;
+	    des->errors += 1;
+	    return 0;
+      }
+
+      if (name_ == "$time")
+	    return new NetESFunc(name_, 64);
+
+      if (name_ == "$random")
+	    return new NetESFunc(name_, 32);
+
+      cerr << get_line() << ": sorry: system function " << name_
+	   << " not supported." << endl;
       des->errors += 1;
       return 0;
 }
@@ -240,9 +253,7 @@ NetExpr* PEConcat::elaborate_expr(Design*des, NetScope*scope) const
 
 NetExpr* PEIdent::elaborate_expr(Design*des, NetScope*scope) const
 {
-	// System identifiers show up in the netlist as identifiers.
-      if (text_[0] == '$')
-	    return new NetEIdent(text_, 64);
+      assert(text_[0] != '$');
 
 	//string name = path+"."+text_;
       assert(scope);
@@ -456,6 +467,10 @@ NetEUnary* PEUnary::elaborate_expr(Design*des, NetScope*scope) const
 
 /*
  * $Log: elab_expr.cc,v $
+ * Revision 1.24  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.23  2000/05/02 03:13:30  steve
  *  Move memories to the NetScope object.
  *
diff --git a/emit.cc b/emit.cc
index 3417094d4..1e5e60886 100644
--- a/emit.cc
+++ b/emit.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: emit.cc,v 1.43 2000/05/02 03:13:31 steve Exp $"
+#ident "$Id: emit.cc,v 1.44 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 /*
@@ -391,6 +391,11 @@ void NetEScope::expr_scan(struct expr_scan_t*tgt) const
       tgt->expr_scope(this);
 }
 
+void NetESFunc::expr_scan(struct expr_scan_t*tgt) const
+{
+      tgt->expr_sfunc(this);
+}
+
 void NetEUFunc::expr_scan(struct expr_scan_t*tgt) const
 {
       tgt->expr_ufunc(this);
@@ -429,6 +434,10 @@ bool emit(ostream&o, const Design*des, const char*type)
 
 /*
  * $Log: emit.cc,v $
+ * Revision 1.44  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.43  2000/05/02 03:13:31  steve
  *  Move memories to the NetScope object.
  *
@@ -565,49 +574,5 @@ bool emit(ostream&o, const Design*des, const char*type)
  *
  * Revision 1.8  1999/04/25 00:44:10  steve
  *  Core handles subsignal expressions.
- *
- * Revision 1.7  1999/04/19 01:59:36  steve
- *  Add memories to the parse and elaboration phases.
- *
- * Revision 1.6  1999/02/08 02:49:56  steve
- *  Turn the NetESignal into a NetNode so
- *  that it can connect to the netlist.
- *  Implement the case statement.
- *  Convince t-vvm to output code for
- *  the case statement.
- *
- * Revision 1.5  1999/02/01 00:26:49  steve
- *  Carry some line info to the netlist,
- *  Dump line numbers for processes.
- *  Elaborate prints errors about port vector
- *  width mismatch
- *  Emit better handles null statements.
- *
- * Revision 1.4  1998/12/01 00:42:14  steve
- *  Elaborate UDP devices,
- *  Support UDP type attributes, and
- *  pass those attributes to nodes that
- *  are instantiated by elaboration,
- *  Put modules into a map instead of
- *  a simple list.
- *
- * Revision 1.3  1998/11/09 18:55:34  steve
- *  Add procedural while loops,
- *  Parse procedural for loops,
- *  Add procedural wait statements,
- *  Add constant nodes,
- *  Add XNOR logic gate,
- *  Make vvm output look a bit prettier.
- *
- * Revision 1.2  1998/11/07 17:05:05  steve
- *  Handle procedural conditional, and some
- *  of the conditional expressions.
- *
- *  Elaborate signals and identifiers differently,
- *  allowing the netlist to hold signal information.
- *
- * Revision 1.1  1998/11/03 23:28:57  steve
- *  Introduce verilog to CVS.
- *
  */
 
diff --git a/netlist.cc b/netlist.cc
index 81bc4dcb4..cabc3708c 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.cc,v 1.121 2000/05/02 03:13:31 steve Exp $"
+#ident "$Id: netlist.cc,v 1.122 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 # include  <cassert>
@@ -2197,6 +2197,21 @@ const NetScope* NetEScope::scope() const
       return scope_;
 }
 
+NetESFunc::NetESFunc(const string&n, unsigned width)
+: name_(n)
+{
+      expr_width(width);
+}
+
+NetESFunc::~NetESFunc()
+{
+}
+
+const string& NetESFunc::name() const
+{
+      return name_;
+}
+
 NetESignal::NetESignal(NetNet*n)
 : NetExpr(n->pin_count()), net_(n)
 {
@@ -2552,6 +2567,10 @@ bool NetUDP::sequ_glob_(string input, char output)
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.122  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.121  2000/05/02 03:13:31  steve
  *  Move memories to the NetScope object.
  *
diff --git a/netlist.h b/netlist.h
index 1e35ac7b2..6bacaddf1 100644
--- a/netlist.h
+++ b/netlist.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.h,v 1.134 2000/05/02 03:13:31 steve Exp $"
+#ident "$Id: netlist.h,v 1.135 2000/05/04 03:37:58 steve Exp $"
 #endif
 
 /*
@@ -2027,19 +2027,17 @@ class NetEScope  : public NetExpr {
  * This node represents a system function call in an expression. The
  * object contains the name of the system function, which the backend
  * uses to to VPI matching.
+ *
+ * XXXX NOTE: parameters are not net supported.
  */
 class NetESFunc  : public NetExpr {
 
     public:
-      NetESFunc(const string&name, NetESignal*, svector<NetExpr*>&);
+      NetESFunc(const string&name, unsigned width);
       ~NetESFunc();
 
       const string& name() const;
 
-      const NetESignal*result() const;
-      unsigned parm_count() const;
-      const NetExpr* parm(unsigned idx) const;
-
       virtual bool set_width(unsigned);
       virtual void dump(ostream&) const;
 
@@ -2048,8 +2046,6 @@ class NetESFunc  : public NetExpr {
 
     private:
       string name_;
-      NetESignal*result_;
-      svector<NetExpr*> parms_;
 
     private: // not implemented
       NetESFunc(const NetESFunc&);
@@ -2505,6 +2501,10 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.135  2000/05/04 03:37:58  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.134  2000/05/02 03:13:31  steve
  *  Move memories to the NetScope object.
  *
diff --git a/parse.y b/parse.y
index 4c59205a9..08f3bb67f 100644
--- a/parse.y
+++ b/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: parse.y,v 1.92 2000/04/22 04:20:19 steve Exp $"
+#ident "$Id: parse.y,v 1.93 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -723,11 +723,11 @@ expr_primary
 		  delete $1;
 		}
 	| SYSTEM_IDENTIFIER
-		{ PEIdent*tmp = new PEIdent($1);
+                { PECallFunction*tmp = new PECallFunction($1);
 		  tmp->set_file(@1.text);
 		  tmp->set_lineno(@1.first_line);
 		  $$ = tmp;
-		  delete $1;
+		  delete $1
 		}
 	| identifier '[' expression ']'
 		{ PEIdent*tmp = new PEIdent($1);
diff --git a/pform_dump.cc b/pform_dump.cc
index 7262f971c..3955be209 100644
--- a/pform_dump.cc
+++ b/pform_dump.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: pform_dump.cc,v 1.55 2000/04/22 04:20:19 steve Exp $"
+#ident "$Id: pform_dump.cc,v 1.56 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 /*
@@ -71,10 +71,13 @@ void PEConcat::dump(ostream&out) const
 void PECallFunction::dump(ostream &out) const
 {
       out << name_ << "(";
-      parms_[0]->dump(out);
-      for (unsigned idx = 1; idx < parms_.count(); ++idx) {
-	    out << ", ";
-	    parms_[idx]->dump(out);
+
+      if (parms_.count() > 0) {
+	    parms_[0]->dump(out);
+	    for (unsigned idx = 1; idx < parms_.count(); ++idx) {
+		  out << ", ";
+		  parms_[idx]->dump(out);
+	    }
       }
       out << ")";
 }
@@ -745,6 +748,10 @@ void PUdp::dump(ostream&out) const
 
 /*
  * $Log: pform_dump.cc,v $
+ * Revision 1.56  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.55  2000/04/22 04:20:19  steve
  *  Add support for force assignment.
  *
diff --git a/set_width.cc b/set_width.cc
index 19cb1d53f..ccf1842c8 100644
--- a/set_width.cc
+++ b/set_width.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: set_width.cc,v 1.12 2000/04/28 18:43:23 steve Exp $"
+#ident "$Id: set_width.cc,v 1.13 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 /*
@@ -237,6 +237,11 @@ bool NetEParam::set_width(unsigned)
       return false;
 }
 
+bool NetESFunc::set_width(unsigned w)
+{
+      return w == expr_width();
+}
+
 /*
  * The signal should automatically pad with zeros to get to th desired
  * width. Do not allow signal bits to be truncated, however.
@@ -295,6 +300,10 @@ bool NetEUnary::set_width(unsigned w)
 
 /*
  * $Log: set_width.cc,v $
+ * Revision 1.13  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.12  2000/04/28 18:43:23  steve
  *  integer division in expressions properly get width.
  *
diff --git a/t-vvm.cc b/t-vvm.cc
index 5729e5d7b..e56c7c2ca 100644
--- a/t-vvm.cc
+++ b/t-vvm.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: t-vvm.cc,v 1.142 2000/05/02 00:58:12 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.143 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -171,7 +171,8 @@ target_vvm::~target_vvm()
 /*
  * This class emits code for the rvalue of a procedural
  * assignment. The expression is evaluated to fit the width
- * specified.
+ * specified. The result is a vvm_bitset_t or equivilent that can be
+ * used for reading values out.
  */
 class vvm_proc_rval  : public expr_scan_t {
 
@@ -190,6 +191,7 @@ class vvm_proc_rval  : public expr_scan_t {
       virtual void expr_concat(const NetEConcat*);
       virtual void expr_ident(const NetEIdent*);
       virtual void expr_memory(const NetEMemory*mem);
+      virtual void expr_sfunc(const NetESFunc*);
       virtual void expr_signal(const NetESignal*);
       virtual void expr_subsignal(const NetESubSignal*sig);
       virtual void expr_ternary(const NetETernary*);
@@ -305,6 +307,24 @@ void vvm_proc_rval::expr_memory(const NetEMemory*mem)
       result = tname;
 }
 
+void vvm_proc_rval::expr_sfunc(const NetESFunc*fun)
+{
+      os_ << "      // " << fun->get_line() << endl;
+
+      const string retval = make_temp();
+      const unsigned retwid = fun->expr_width();
+
+      os_ << "      vpip_bit_t " << retval << "_bits["<<retwid<<"];" << endl;
+
+      os_ << "      vpip_callfunc(\"" << fun->name() << "\", "
+	  << retval<<"_bits, " << retwid << ");" << endl;
+
+      os_ << "      vvm_bitset_t " << retval << "(" << retval<<"_bits, "
+	  << retwid << ");" << endl;
+
+      result = retval;
+}
+
 /*
  * A bitset reference to a signal can be done simply by referring to
  * the same bits as the signal. We onlt need to copy the bits pointer
@@ -608,9 +628,9 @@ class vvm_parm_rval  : public expr_scan_t {
 
     private:
       virtual void expr_const(const NetEConst*);
-      virtual void expr_ident(const NetEIdent*);
       virtual void expr_memory(const NetEMemory*);
       virtual void expr_scope(const NetEScope*);
+      virtual void expr_sfunc(const NetESFunc*);
       virtual void expr_signal(const NetESignal*);
 
     private:
@@ -673,7 +693,7 @@ void vvm_parm_rval::expr_const(const NetEConst*expr)
       return;
 }
 
-void vvm_parm_rval::expr_ident(const NetEIdent*expr)
+void vvm_parm_rval::expr_sfunc(const NetESFunc*expr)
 {
       if (expr->name() == "$time") {
 	    result = string("vpip_sim_time()");
@@ -2692,6 +2712,10 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.143  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.142  2000/05/02 00:58:12  steve
  *  Move signal tables to the NetScope class.
  *
diff --git a/target.cc b/target.cc
index d122d8b4a..065a0cac0 100644
--- a/target.cc
+++ b/target.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: target.cc,v 1.37 2000/04/23 03:45:24 steve Exp $"
+#ident "$Id: target.cc,v 1.38 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  "target.h"
@@ -323,6 +323,12 @@ void expr_scan_t::expr_scope(const NetEScope*)
 	    "unhandled expr_scope." << endl;
 }
 
+void expr_scan_t::expr_sfunc(const NetESFunc*)
+{
+      cerr << "expr_scan_t (" << typeid(*this).name() << "): "
+	    "unhandled expr_sfunc." << endl;
+}
+
 void expr_scan_t::expr_signal(const NetESignal*)
 {
       cerr << "expr_scan_t (" << typeid(*this).name() << "): "
@@ -361,6 +367,10 @@ void expr_scan_t::expr_binary(const NetEBinary*ex)
 
 /*
  * $Log: target.cc,v $
+ * Revision 1.38  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.37  2000/04/23 03:45:24  steve
  *  Add support for the procedural release statement.
  *
diff --git a/target.h b/target.h
index 9641a2abc..1dc677299 100644
--- a/target.h
+++ b/target.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: target.h,v 1.36 2000/04/23 03:45:25 steve Exp $"
+#ident "$Id: target.h,v 1.37 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -130,6 +130,7 @@ struct expr_scan_t {
       virtual void expr_ident(const NetEIdent*);
       virtual void expr_memory(const NetEMemory*);
       virtual void expr_scope(const NetEScope*);
+      virtual void expr_sfunc(const NetESFunc*);
       virtual void expr_signal(const NetESignal*);
       virtual void expr_subsignal(const NetESubSignal*);
       virtual void expr_ternary(const NetETernary*);
@@ -155,6 +156,10 @@ extern const struct target *target_table[];
 
 /*
  * $Log: target.h,v $
+ * Revision 1.37  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.36  2000/04/23 03:45:25  steve
  *  Add support for the procedural release statement.
  *
@@ -185,47 +190,5 @@ extern const struct target *target_table[];
  *
  * Revision 1.30  2000/03/29 04:37:11  steve
  *  New and improved combinational primitives.
- *
- * Revision 1.29  2000/02/23 02:56:56  steve
- *  Macintosh compilers do not support ident.
- *
- * Revision 1.28  2000/01/13 03:35:35  steve
- *  Multiplication all the way to simulation.
- *
- * Revision 1.27  1999/11/28 23:42:03  steve
- *  NetESignal object no longer need to be NetNode
- *  objects. Let them keep a pointer to NetNet objects.
- *
- * Revision 1.26  1999/11/27 19:07:58  steve
- *  Support the creation of scopes.
- *
- * Revision 1.25  1999/11/21 00:13:09  steve
- *  Support memories in continuous assignments.
- *
- * Revision 1.24  1999/11/14 23:43:46  steve
- *  Support combinatorial comparators.
- *
- * Revision 1.23  1999/11/14 20:24:28  steve
- *  Add support for the LPM_CLSHIFT device.
- *
- * Revision 1.22  1999/11/04 03:53:26  steve
- *  Patch to synthesize unary ~ and the ternary operator.
- *  Thanks to Larry Doolittle <LRDoolittle@lbl.gov>.
- *
- *  Add the LPM_MUX device, and integrate it with the
- *  ternary synthesis from Larry. Replace the lpm_mux
- *  generator in t-xnf.cc to use XNF EQU devices to
- *  put muxs into function units.
- *
- *  Rewrite elaborate_net for the PETernary class to
- *  also use the LPM_MUX device.
- *
- * Revision 1.21  1999/11/01 02:07:41  steve
- *  Add the synth functor to do generic synthesis
- *  and add the LPM_FF device to handle rows of
- *  flip-flops.
- *
- * Revision 1.20  1999/10/10 01:59:55  steve
- *  Structural case equals device.
  */
 #endif
diff --git a/vpi/Makefile.in b/vpi/Makefile.in
index 8d7ba2396..a041e1cd9 100644
--- a/vpi/Makefile.in
+++ b/vpi/Makefile.in
@@ -18,7 +18,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.9 2000/01/23 23:54:36 steve Exp $"
+#ident "$Id: Makefile.in,v 1.10 2000/05/04 03:37:59 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -52,8 +52,8 @@ all: system.vpi
 	$(CC) -Wall $(CPPFLAGS) -I$(srcdir) -MD -c $< -o $*.o
 	mv $*.d dep
 
-O = sys_table.o sys_display.o sys_finish.o sys_readmem.o sys_readmem_lex.o \
-sys_vcd.o
+O = sys_table.o sys_display.o sys_finish.o sys_random.o \
+sys_readmem.o sys_readmem_lex.o sys_vcd.o
 
 system.vpi: $O
 	$(CC) -shared -o $@ $O
diff --git a/vpi/sys_random.c b/vpi/sys_random.c
new file mode 100644
index 000000000..1889b7592
--- /dev/null
+++ b/vpi/sys_random.c
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2000 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form under the terms of the GNU
+ *    General Public License as published by the Free Software
+ *    Foundation; either version 2 of the License, or (at your option)
+ *    any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program; if not, write to the Free Software
+ *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+#if !defined(WINNT) && !defined(macintosh)
+#ident "$Id: sys_random.c,v 1.1 2000/05/04 03:37:59 steve Exp $"
+#endif
+
+# include  <vpi_user.h>
+# include  <assert.h>
+# include  <stdlib.h>
+
+/*
+ * Implement the $random system function. For now, ignore any
+ * parameters and only produce a random number.
+ */
+static int sys_random_calltf(char*name)
+{
+      s_vpi_value val;
+      vpiHandle call_handle;
+
+      call_handle = vpi_handle(vpiSysTfCall, 0);
+      assert(call_handle);
+
+      val.format = vpiIntVal;
+      val.value.integer = random();
+
+      vpi_put_value(call_handle, &val, 0, vpiNoDelay);
+
+      return 0;
+}
+
+static int sys_random_sizetf(char*x)
+{
+      return 32;
+}
+
+void sys_random_register()
+{
+      s_vpi_systf_data tf_data;
+
+      tf_data.type   = vpiSysFunc;
+      tf_data.tfname = "$random";
+      tf_data.calltf = sys_random_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf = sys_random_sizetf;
+      tf_data.user_data = "$random";
+      vpi_register_systf(&tf_data);
+}
+
+/*
+ * $Log: sys_random.c,v $
+ * Revision 1.1  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
+ */
+
diff --git a/vpi/sys_table.c b/vpi/sys_table.c
index 692d1c218..9bbdecb23 100644
--- a/vpi/sys_table.c
+++ b/vpi/sys_table.c
@@ -17,17 +17,19 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: sys_table.c,v 1.4 2000/02/23 02:56:56 steve Exp $"
+#ident "$Id: sys_table.c,v 1.5 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 extern void sys_finish_register();
 extern void sys_display_register();
+extern void sys_random_register();
 extern void sys_readmem_register();
 extern void sys_vcd_register();
 
 void (*vlog_startup_routines[])() = {
       sys_finish_register,
       sys_display_register,
+      sys_random_register,
       sys_readmem_register,
       sys_vcd_register,
       0
@@ -36,6 +38,10 @@ void (*vlog_startup_routines[])() = {
 
 /*
  * $Log: sys_table.c,v $
+ * Revision 1.5  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.4  2000/02/23 02:56:56  steve
  *  Macintosh compilers do not support ident.
  *
diff --git a/vpi/vpi_user.h b/vpi/vpi_user.h
index 3307e216b..8d71306d4 100644
--- a/vpi/vpi_user.h
+++ b/vpi/vpi_user.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_user.h,v 1.14 2000/03/08 04:36:54 steve Exp $"
+#ident "$Id: vpi_user.h,v 1.15 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -108,6 +108,7 @@ typedef struct t_vpi_value {
 #define vpiNamedFork   35
 #define vpiNet         36
 #define vpiReg         48
+#define vpiSysFuncCall 56
 #define vpiSysTaskCall 57
 #define vpiTask        59
 #define vpiTimeVar     63
@@ -230,6 +231,10 @@ extern void (*vlog_startup_routines[])();
 
 /*
  * $Log: vpi_user.h,v $
+ * Revision 1.15  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.14  2000/03/08 04:36:54  steve
  *  Redesign the implementation of scopes and parameters.
  *  I now generate the scopes and notice the parameters
diff --git a/vvm/vpi_priv.c b/vvm/vpi_priv.c
index 9127fbb33..8f51ab785 100644
--- a/vvm/vpi_priv.c
+++ b/vvm/vpi_priv.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_priv.c,v 1.5 2000/02/23 02:56:56 steve Exp $"
+#ident "$Id: vpi_priv.c,v 1.6 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -38,7 +38,8 @@ struct systf_entry {
       s_vpi_systf_data systf_data;
 };
 
-static struct systf_entry*systf_list = 0;
+static struct systf_entry*systf_func_list = 0;
+static struct systf_entry*systf_task_list = 0;
 
 /* This is the handle of the task currently being called. */
 static struct __vpiSysTaskCall*vpip_cur_task;
@@ -49,13 +50,15 @@ void vpip_calltask(const char*fname, unsigned nparms, vpiHandle*parms)
       struct systf_entry*idx;
       struct __vpiSysTaskCall cur_task;
       cur_task.base.vpi_type = &vpip_systask_rt;
-      cur_task.args = parms;
+      cur_task.args  = parms;
       cur_task.nargs = nparms;
+      cur_task.res   = 0;
+      cur_task.nres  = 0;
 
       vpip_cur_task = &cur_task;
 
 	/* Look for a systf function to invoke. */
-      for (idx = systf_list ;  idx ;  idx = idx->next)
+      for (idx = systf_task_list ;  idx ;  idx = idx->next)
 	    if (strcmp(fname, idx->systf_data.tfname) == 0) {
 		  cur_task.info = &idx->systf_data;
 		  idx->systf_data.calltf(idx->systf_data.user_data);
@@ -69,6 +72,39 @@ void vpip_calltask(const char*fname, unsigned nparms, vpiHandle*parms)
       vpi_printf("Call %s\n", fname);
 }
 
+/*
+ * System functions are kept in the same sort of table as the system
+ * tasks, and we call them in a similar manner.
+ *
+ * XXXX Haven't handled the return value yet.
+ */
+void vpip_callfunc(const char*fname, vpip_bit_t*res, unsigned nres)
+{
+      struct systf_entry*idx;
+      struct __vpiSysTaskCall cur_task;
+      cur_task.base.vpi_type = &vpip_sysfunc_rt;
+      cur_task.args  = 0;
+      cur_task.nargs = 0;
+      cur_task.res = res;
+      cur_task.nres = nres;
+
+      vpip_cur_task = &cur_task;
+
+	/* Look for a systf function to invoke. */
+      for (idx = systf_func_list ;  idx ;  idx = idx->next)
+	    if (strcmp(fname, idx->systf_data.tfname) == 0) {
+		  cur_task.info = &idx->systf_data;
+		  idx->systf_data.calltf(idx->systf_data.user_data);
+		  return;
+	    }
+
+
+	/* Finally, if nothing is found then something is not
+	   right. Print out the function name all the parameters
+	   passed, so that someone can deal with it. */
+      vpi_printf("Call %s with width==%u\n", fname, nres);
+}
+
 
 int vpi_free_object(vpiHandle ref)
 {
@@ -168,12 +204,26 @@ void vpi_register_systf(const struct t_vpi_systf_data*systf)
       struct systf_entry*cur = calloc(1, sizeof(struct systf_entry));
       cur->systf_data = *systf;
       cur->systf_data.tfname = strdup(systf->tfname);
-      cur->next = systf_list;
-      systf_list = cur;
+      switch (systf->type) {
+	  case vpiSysFunc:
+	    cur->next = systf_func_list;
+	    systf_func_list = cur;
+	    break;
+	  case vpiSysTask:
+	    cur->next = systf_task_list;
+	    systf_task_list = cur;
+	    break;
+	  default:
+	    assert(0);
+      }
 }
 
 /*
  * $Log: vpi_priv.c,v $
+ * Revision 1.6  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.5  2000/02/23 02:56:56  steve
  *  Macintosh compilers do not support ident.
  *
diff --git a/vvm/vpi_priv.h b/vvm/vpi_priv.h
index eb402d70f..19c3f5432 100644
--- a/vvm/vpi_priv.h
+++ b/vvm/vpi_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_priv.h,v 1.15 2000/04/22 04:20:20 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.16 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 /*
@@ -217,6 +217,7 @@ struct __vpiSignal {
 
 
 extern const struct __vpirt vpip_systask_rt;
+extern const struct __vpirt vpip_sysfunc_rt;
 struct __vpiSysTaskCall {
       struct __vpiHandle base;
 
@@ -224,6 +225,9 @@ struct __vpiSysTaskCall {
       vpiHandle*args;
       unsigned nargs;
 
+      vpip_bit_t*res;
+      unsigned nres;
+
       const char*file;
       unsigned lineno;
       int subtype;
@@ -285,6 +289,12 @@ extern vpiHandle vpip_make_time_var(struct __vpiTimeVar*ref,
 /* Use this function to call a registered task. */
 extern void vpip_calltask(const char*name, unsigned nparms, vpiHandle*parms);
 
+/*
+ * This calls a system function with a given name. The return value is
+ * taken by the res[] array.
+ */
+extern void vpip_callfunc(const char*name, vpip_bit_t*res, unsigned nres);
+
 extern void vpip_run_value_changes(struct __vpiSignal*sig);
 
 /*
@@ -344,6 +354,10 @@ extern int vpip_finished();
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.16  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.15  2000/04/22 04:20:20  steve
  *  Add support for force assignment.
  *
diff --git a/vvm/vpi_systask.c b/vvm/vpi_systask.c
index 159c78e25..9a8f4b4de 100644
--- a/vvm/vpi_systask.c
+++ b/vvm/vpi_systask.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_systask.c,v 1.3 2000/02/23 02:56:56 steve Exp $"
+#ident "$Id: vpi_systask.c,v 1.4 2000/05/04 03:37:59 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -45,8 +45,53 @@ const struct __vpirt vpip_systask_rt = {
       systask_iter
 };
 
+/*
+ * A value *can* be put to a vpiSysFuncCall object. This is how the
+ * return value is set. The value that is given should be converted to
+ * bits and set into the return value bit array.
+ */
+static vpiHandle sysfunc_put_value(vpiHandle ref, p_vpi_value val,
+				   p_vpi_time t, int flag)
+{
+      long tmp;
+      int idx;
+
+      struct __vpiSysTaskCall*rfp = (struct __vpiSysTaskCall*)ref;
+      assert(ref->vpi_type->type_code == vpiSysFuncCall);
+
+	/* There *must* be a return value array. */
+      assert(rfp->res);
+      assert(rfp->nres > 0);
+
+	/* XXXX For now, only support very specific formats. */
+      assert(val->format == vpiIntVal);
+      assert(rfp->nres <= (8*sizeof val->value.integer));
+
+      tmp = val->value.integer;
+      for (idx = 0 ;  idx < rfp->nres ;  idx += 1) {
+	    rfp->res[idx] =  (tmp&1) ? St1 : St0;
+	    tmp >>= 1;
+      }
+
+      return 0;
+}
+
+const struct __vpirt vpip_sysfunc_rt = {
+      vpiSysFuncCall,
+      0,
+      0,
+      0,
+      sysfunc_put_value,
+      0,
+      systask_iter
+};
+
 /*
  * $Log: vpi_systask.c,v $
+ * Revision 1.4  2000/05/04 03:37:59  steve
+ *  Add infrastructure for system functions, move
+ *  $time to that structure and add $random.
+ *
  * Revision 1.3  2000/02/23 02:56:56  steve
  *  Macintosh compilers do not support ident.
  *