diff --git a/design_dump.cc b/design_dump.cc
index 98917456e..6719f7e08 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 1.83 2000/05/07 04:37:56 steve Exp $"
+#ident "$Id: design_dump.cc,v 1.84 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 /*
@@ -850,7 +850,12 @@ void NetEScope::dump(ostream&o) const
 
 void NetESFunc::dump(ostream&o) const
 {
-      o << name_ << "()";
+      o << name_ << "(";
+      if (nparms() > 0)
+	    o << *parm(0);
+      for (unsigned idx = 1 ;  idx < nparms() ;  idx += 1)
+	    o << ", " << *parm(idx);
+      o << ")";
 }
 
 void NetESignal::dump(ostream&o) const
@@ -955,6 +960,10 @@ void Design::dump(ostream&o) const
 
 /*
  * $Log: design_dump.cc,v $
+ * Revision 1.84  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.83  2000/05/07 04:37:56  steve
  *  Carry strength values from Verilog source to the
  *  pform and netlist for gates.
diff --git a/dup_expr.cc b/dup_expr.cc
index 3d5191d75..49dc20c82 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 1.3 2000/05/04 03:37:58 steve Exp $"
+#ident "$Id: dup_expr.cc,v 1.4 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 # include  "netlist.h"
@@ -31,11 +31,19 @@ NetEScope* NetEScope::dup_expr() const
 
 NetESFunc* NetESFunc::dup_expr() const
 {
-      return new NetESFunc(name_, expr_width());
+      NetESFunc*tmp = new NetESFunc(name_, expr_width(), nparms());
+      for (unsigned idx = 0 ;  idx < nparms() ;  idx += 1)
+	    tmp->parm(idx, tmp->parm(idx)->dup_expr());
+
+      return tmp;
 }
 
 /*
  * $Log: dup_expr.cc,v $
+ * Revision 1.4  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.3  2000/05/04 03:37:58  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.
diff --git a/elab_expr.cc b/elab_expr.cc
index 98ad43576..5b653cb27 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: elab_expr.cc,v 1.24 2000/05/04 03:37:58 steve Exp $"
+#ident "$Id: elab_expr.cc,v 1.25 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 
@@ -142,25 +142,21 @@ NetEBinary* PEBinary::elaborate_expr_base_(Design*des,
       return tmp;
 }
 
-NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*) const
+NetExpr* PECallFunction::elaborate_sfunc_(Design*des, NetScope*scope) const
 {
-      if (parms_.count() > 0) {
-	    cerr << get_line() << ": sorry: system function "
-		  "parmaeters not supported." << endl;
-	    des->errors += 1;
-	    return 0;
-      }
+      unsigned wid = 32;
 
       if (name_ == "$time")
-	    return new NetESFunc(name_, 64);
+	    wid = 64;
 
-      if (name_ == "$random")
-	    return new NetESFunc(name_, 32);
+      NetESFunc*fun = new NetESFunc(name_, wid, parms_.count());
+      for (unsigned idx = 0 ;  idx < parms_.count() ;  idx += 1) {
+	    PExpr*expr = parms_[idx];
+	    NetExpr*tmp = expr->elaborate_expr(des, scope);
+	    fun->parm(idx, tmp);
+      }
 
-      cerr << get_line() << ": sorry: system function " << name_
-	   << " not supported." << endl;
-      des->errors += 1;
-      return 0;
+      return fun;
 }
 
 NetExpr* PECallFunction::elaborate_expr(Design*des, NetScope*scope) const
@@ -467,6 +463,10 @@ NetEUnary* PEUnary::elaborate_expr(Design*des, NetScope*scope) const
 
 /*
  * $Log: elab_expr.cc,v $
+ * Revision 1.25  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.24  2000/05/04 03:37:58  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.
diff --git a/netlist.cc b/netlist.cc
index a60036f9f..7a1696517 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: netlist.cc,v 1.123 2000/05/07 04:37:56 steve Exp $"
+#ident "$Id: netlist.cc,v 1.124 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 # include  <cassert>
@@ -2234,14 +2234,22 @@ const NetScope* NetEScope::scope() const
       return scope_;
 }
 
-NetESFunc::NetESFunc(const string&n, unsigned width)
+NetESFunc::NetESFunc(const string&n, unsigned width, unsigned np)
 : name_(n)
 {
       expr_width(width);
+      nparms_ = np;
+      parms_ = new NetExpr*[np];
+      for (unsigned idx = 0 ;  idx < nparms_ ;  idx += 1)
+	    parms_[idx] = 0;
 }
 
 NetESFunc::~NetESFunc()
 {
+      for (unsigned idx = 0 ;  idx < nparms_ ;  idx += 1)
+	    if (parms_[idx]) delete parms_[idx];
+
+      delete[]parms_;
 }
 
 const string& NetESFunc::name() const
@@ -2249,6 +2257,31 @@ const string& NetESFunc::name() const
       return name_;
 }
 
+unsigned NetESFunc::nparms() const
+{
+      return nparms_;
+}
+
+void NetESFunc::parm(unsigned idx, NetExpr*v)
+{
+      assert(idx < nparms_);
+      if (parms_[idx])
+	    delete parms_[idx];
+      parms_[idx] = v;
+}
+
+const NetExpr* NetESFunc::parm(unsigned idx) const
+{
+      assert(idx < nparms_);
+      return parms_[idx];
+}
+
+NetExpr* NetESFunc::parm(unsigned idx)
+{
+      assert(idx < nparms_);
+      return parms_[idx];
+}
+
 NetESignal::NetESignal(NetNet*n)
 : NetExpr(n->pin_count()), net_(n)
 {
@@ -2604,6 +2637,10 @@ bool NetUDP::sequ_glob_(string input, char output)
 
 /*
  * $Log: netlist.cc,v $
+ * Revision 1.124  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.123  2000/05/07 04:37:56  steve
  *  Carry strength values from Verilog source to the
  *  pform and netlist for gates.
diff --git a/netlist.h b/netlist.h
index 0f46e6d0a..5e79cbb9c 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 1.136 2000/05/07 04:37:56 steve Exp $"
+#ident "$Id: netlist.h,v 1.137 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 /*
@@ -2035,18 +2035,21 @@ 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.
+ * uses to do VPI matching.
  */
 class NetESFunc  : public NetExpr {
 
     public:
-      NetESFunc(const string&name, unsigned width);
+      NetESFunc(const string&name, unsigned width, unsigned nprms);
       ~NetESFunc();
 
       const string& name() const;
 
+      unsigned nparms() const;
+      void parm(unsigned idx, NetExpr*expr);
+      NetExpr* parm(unsigned idx);
+      const NetExpr* parm(unsigned idx) const;
+
       virtual bool set_width(unsigned);
       virtual void dump(ostream&) const;
 
@@ -2055,6 +2058,8 @@ class NetESFunc  : public NetExpr {
 
     private:
       string name_;
+      unsigned nparms_;
+      NetExpr**parms_;
 
     private: // not implemented
       NetESFunc(const NetESFunc&);
@@ -2510,6 +2515,10 @@ extern ostream& operator << (ostream&, NetNet::Type);
 
 /*
  * $Log: netlist.h,v $
+ * Revision 1.137  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.136  2000/05/07 04:37:56  steve
  *  Carry strength values from Verilog source to the
  *  pform and netlist for gates.
diff --git a/t-vvm.cc b/t-vvm.cc
index a029eb3d5..9cffc78f9 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 1.144 2000/05/07 04:37:56 steve Exp $"
+#ident "$Id: t-vvm.cc,v 1.145 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 # include  <iostream>
@@ -94,7 +94,7 @@ class target_vvm : public target_t {
               void proc_condit_fun(ostream&os, const NetCondit*);
       virtual bool proc_force(ostream&os, const NetForce*);
       virtual void proc_forever(ostream&os, const NetForever*);
-      virtual bool target_vvm::proc_release(ostream&os, const NetRelease*);
+      virtual bool proc_release(ostream&os, const NetRelease*);
       virtual void proc_repeat(ostream&os, const NetRepeat*);
       virtual void proc_stask(ostream&os, const NetSTask*);
       virtual bool proc_trigger(ostream&os, const NetEvTrig*);
@@ -222,14 +222,14 @@ target_vvm::~target_vvm()
 class vvm_proc_rval  : public expr_scan_t {
 
     public:
-      explicit vvm_proc_rval(ostream&os, unsigned i)
-      : result(""), os_(os), indent_(i) { }
+      explicit vvm_proc_rval(ostream&os, target_vvm*t)
+      : result(""), os_(os), tgt_(t) { }
 
       string result;
 
     private:
       ostream&os_;
-      unsigned indent_;
+      target_vvm*tgt_;
 
     private:
       virtual void expr_const(const NetEConst*);
@@ -245,6 +245,34 @@ class vvm_proc_rval  : public expr_scan_t {
       virtual void expr_ufunc(const NetEUFunc*);
 };
 
+/*
+ * The vvm_parm_rval class scans expressions for the purpose of making
+ * parameters for system tasks/functions. Thus, the generated code is
+ * geared towards making the handles needed to make the call.
+ *
+ * The result of any parm rval scan is a vpiHandle, or a string that
+ * automatically converts to a vpiHandle on assignment.
+ */
+class vvm_parm_rval  : public expr_scan_t {
+
+    public:
+      explicit vvm_parm_rval(ostream&o, target_vvm*t)
+      : result(""), os_(o), tgt_(t) { }
+
+      string result;
+
+    private:
+      virtual void expr_const(const NetEConst*);
+      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:
+      ostream&os_;
+      target_vvm*tgt_;
+};
+
 /*
  * Handle the concatenation operator in a procedural r-value
  * expression. Evaluate the concatenation into a temporary variable
@@ -269,7 +297,7 @@ void vvm_proc_rval::expr_concat(const NetEConcat*expr)
 		  pp->expr_scan(this);
 
 		  for (unsigned bit = 0 ; bit < pp->expr_width() ; bit += 1) {
-			os_ << setw(indent_) << "" << tname << "[" << pos <<
+			os_ << "      " << tname << "[" << pos <<
 			      "] = " << result << "[" << bit << "];" <<
 			      endl;
 			pos+= 1;
@@ -359,10 +387,38 @@ void vvm_proc_rval::expr_sfunc(const NetESFunc*fun)
       const string retval = make_temp();
       const unsigned retwid = fun->expr_width();
 
+	/* Make any parameters that might be needed to be passed to
+	   the function. */
+
+      const string parmtab = make_temp();
+      if (fun->nparms() > 0) {
+	    os_ << "      vpiHandle " << parmtab
+		<< "["<<fun->nparms()<<"];" << endl;
+
+	    for (unsigned idx = 0 ;  idx < fun->nparms() ;  idx += 1) {
+		  vvm_parm_rval scan(os_, tgt_);
+		  fun->parm(idx)->expr_scan(&scan);
+
+		  os_ << "      " << parmtab <<"["<<idx<<"] = "
+		      << scan.result << ";" << endl;
+	    }
+      }
+
+	/* Draw the call to the function. Create a vpip_bit_t array to
+	   receive the return value, and make it into a vvm_bitset_t
+	   when the call returns. */
+
       os_ << "      vpip_bit_t " << retval << "_bits["<<retwid<<"];" << endl;
 
       os_ << "      vpip_callfunc(\"" << fun->name() << "\", "
-	  << retval<<"_bits, " << retwid << ");" << endl;
+	  << retwid << ", " << retval<<"_bits";
+
+      if (fun->nparms() == 0)
+	    os_ << ", 0, 0";
+      else
+	    os_ << ", " << fun->nparms() << ", " << parmtab;
+
+      os_ << ");" << endl;
 
       os_ << "      vvm_bitset_t " << retval << "(" << retval<<"_bits, "
 	  << retwid << ");" << endl;
@@ -555,87 +611,87 @@ void vvm_proc_rval::expr_binary(const NetEBinary*expr)
 
       switch (expr->op()) {
 	  case 'a': // logical and (&&)
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_land("
+	    os_ << "      " << result << "[0] = vvm_binop_land("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'E': // ===
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_eeq("
+	    os_ << "      " << result << "[0] = vvm_binop_eeq("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'e': // ==
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_eq("
+	    os_ << "      " << result << "[0] = vvm_binop_eq("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'G': // >=
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_ge("
+	    os_ << "      " << result << "[0] = vvm_binop_ge("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'l': // left shift(<<)
-	    os_ << setw(indent_) << "" << "vvm_binop_shiftl(" << result
+	    os_ << "      " << "vvm_binop_shiftl(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case 'L': // <=
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_le("
+	    os_ << "      " << result << "[0] = vvm_binop_le("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'N': // !==
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_nee("
+	    os_ << "      " << result << "[0] = vvm_binop_nee("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'n':
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_ne("
+	    os_ << "      " << result << "[0] = vvm_binop_ne("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case '<':
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_lt("
+	    os_ << "      " << result << "[0] = vvm_binop_lt("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case '>':
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_gt("
+	    os_ << "      " << result << "[0] = vvm_binop_gt("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'o': // logical or (||)
-	    os_ << setw(indent_) << "" << result << "[0] = vvm_binop_lor("
+	    os_ << "      " << result << "[0] = vvm_binop_lor("
 		<< lres << "," << rres << ");" << endl;
 	    break;
 	  case 'r': // right shift(>>)
-	    os_ << setw(indent_) << "" << "vvm_binop_shiftr(" << result
+	    os_ << "      " << "vvm_binop_shiftr(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case 'X':
-	    os_ << setw(indent_) << "" << "vvm_binop_xnor(" << result
+	    os_ << "      " << "vvm_binop_xnor(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case '+':
-	    os_ << setw(indent_) << "" << "vvm_binop_plus(" << result
+	    os_ << "      " << "vvm_binop_plus(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case '-':
-	    os_ << setw(indent_) << "" << "vvm_binop_minus(" << result
+	    os_ << "      " << "vvm_binop_minus(" << result
 		<< ", " << lres << "," << rres << ");" << endl;
 	    break;
 	  case '&':
-	    os_ << setw(indent_) << "" << "vvm_binop_and(" << result
+	    os_ << "      " << "vvm_binop_and(" << result
 		<< ", " << lres << ", " << rres << ");" << endl;
 	    break;
 	  case '|':
-	    os_ << setw(indent_) << "" << "vvm_binop_or(" << result
+	    os_ << "      " << "vvm_binop_or(" << result
 		<< ", " << lres << ", " << rres << ");" << endl;
 	    break;
 	  case '^':
-	    os_ << setw(indent_) << "" << "vvm_binop_xor(" << result
+	    os_ << "      " << "vvm_binop_xor(" << result
 		<< ", " << lres << ", " << rres << ");" << endl;
 	    break;
 	  case '*':
-	    os_ << setw(indent_) << "" << "vvm_binop_mult(" << result
+	    os_ << "      " << "vvm_binop_mult(" << result
 		<< "," << lres << "," << rres << ");" << endl;
 	    break;
 	  case '/':
-	    os_ << setw(indent_) << "" << "vvm_binop_idiv(" << result
+	    os_ << "      " << "vvm_binop_idiv(" << result
 		<< "," << lres << "," << rres << ");" << endl;
 	    break;
 	  case '%':
-	    os_ << setw(indent_) << "" << "vvm_binop_imod(" << result
+	    os_ << "      " << "vvm_binop_imod(" << result
 		<< "," << lres << "," << rres << ");" << endl;
 	    break;
 	  default:
@@ -648,41 +704,13 @@ void vvm_proc_rval::expr_binary(const NetEBinary*expr)
       }
 }
 
-static string emit_proc_rval(ostream&os, unsigned indent, const NetExpr*expr)
+static string emit_proc_rval(ostream&os, target_vvm*tgt, const NetExpr*expr)
 {
-      vvm_proc_rval scan (os, indent);
+      vvm_proc_rval scan (os, tgt);
       expr->expr_scan(&scan);
       return scan.result;
 }
 
-/*
- * The vvm_parm_rval class scans expressions for the purpose of making
- * parameters for system tasks/functions. Thus, the generated code is
- * geared towards making the handles needed to make the call.
- *
- * The result of any parm rval scan is a vpiHandle, or a string that
- * automatically converts to a vpiHandle on assignment.
- */
-class vvm_parm_rval  : public expr_scan_t {
-
-    public:
-      explicit vvm_parm_rval(ostream&o, target_vvm*t)
-      : result(""), os_(o), tgt_(t) { }
-
-      string result;
-
-    private:
-      virtual void expr_const(const NetEConst*);
-      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:
-      ostream&os_;
-      target_vvm*tgt_;
-};
-
 void vvm_parm_rval::expr_const(const NetEConst*expr)
 {
       if (expr->value().is_string()) {
@@ -770,7 +798,7 @@ void vvm_parm_rval::expr_memory(const NetEMemory*mem)
 
 	      /* Otherwise, evaluate the index at run time and use
 		 that to select the memory word. */
-	    string rval = emit_proc_rval(tgt_->defn, 6, mem->index());
+	    string rval = emit_proc_rval(tgt_->defn, tgt_, mem->index());
 	    result = "vpi_handle_by_index(&" + mangle(mem->name()) +
 		  ".base, " + rval + ".as_unsigned())";
       }
@@ -1934,7 +1962,7 @@ void target_vvm::proc_assign(ostream&os, const NetAssign*net)
 	    return;
       }
 
-      string rval = emit_proc_rval(defn, 8, net->rval());
+      string rval = emit_proc_rval(defn, this, net->rval());
 
       defn << "      // " << net->get_line() << ": " << endl;
 
@@ -1942,7 +1970,7 @@ void target_vvm::proc_assign(ostream&os, const NetAssign*net)
 
 	      // This is a bit select. Assign the low bit of the rval
 	      // to the selected bit of the lval.
-	    string bval = emit_proc_rval(defn, 8, net->bmux());
+	    string bval = emit_proc_rval(defn, this, net->bmux());
 
 	    defn << "      switch (" << bval << ".as_unsigned()) {" << endl;
 
@@ -1997,7 +2025,7 @@ void target_vvm::proc_assign_mem(ostream&os, const NetAssignMem*amem)
 	   << mangle(amem->index()->name()) << ".nbits);" << endl;
 
 	/* Evaluate the rval that gets written into the memory word. */
-      string rval = emit_proc_rval(defn, 8, amem->rval());
+      string rval = emit_proc_rval(defn, this, amem->rval());
 
 
       const NetMemory*mem = amem->memory();
@@ -2018,7 +2046,7 @@ void target_vvm::proc_assign_mem(ostream&os, const NetAssignMem*amem)
 
 void target_vvm::proc_assign_nb(ostream&os, const NetAssignNB*net)
 {
-      string rval = emit_proc_rval(defn, 8, net->rval());
+      string rval = emit_proc_rval(defn, this, net->rval());
       const unsigned long delay = net->rise_time();
 
       if (net->bmux()) {
@@ -2030,7 +2058,7 @@ void target_vvm::proc_assign_nb(ostream&os, const NetAssignNB*net)
 		 better generating a demux device and doing the assign
 		 to the device input. Food for thought. */
 
-	    string bval = emit_proc_rval(defn, 8, net->bmux());
+	    string bval = emit_proc_rval(defn, this, net->bmux());
 	    defn << "      switch (" << bval << ".as_unsigned()) {" << endl;
 
 	    for (unsigned idx = 0 ;  idx < net->pin_count() ;  idx += 1) {
@@ -2068,7 +2096,7 @@ void target_vvm::proc_assign_mem_nb(ostream&os, const NetAssignMemNB*amem)
 
 
 	/* Evaluate the rval that gets written into the memory word. */
-      string rval = emit_proc_rval(defn, 8, amem->rval());
+      string rval = emit_proc_rval(defn, this, amem->rval());
 
       const NetMemory*mem = amem->memory();
 
@@ -2198,7 +2226,7 @@ void target_vvm::proc_case(ostream&os, const NetCase*net)
       }
 
       defn << "      /* case (" << *net->expr() << ") */" << endl;
-      string expr = emit_proc_rval(defn, 8, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
 
       unsigned exit_step = thread_step_ + 1;
       thread_step_ += 1;
@@ -2219,7 +2247,7 @@ void target_vvm::proc_case(ostream&os, const NetCase*net)
 	    thread_step_ += 1;
 
 	    defn << "      /* " << *net->expr(idx) << " */" << endl;
-	    string guard = emit_proc_rval(defn, 8, net->expr(idx));
+	    string guard = emit_proc_rval(defn, this, net->expr(idx));
 
 	    defn << "      if (B_IS1(" << test_func << "(" << guard << ","
 	       << expr << "))) {" << endl;
@@ -2323,7 +2351,7 @@ void target_vvm::proc_case_fun(ostream&os, const NetCase*net)
 
       defn << "      do {" << endl;
 
-      string expr = emit_proc_rval(defn, 6, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
 
       unsigned default_idx = net->nitems();
       for (unsigned idx = 0 ;  idx < net->nitems() ;  idx += 1) {
@@ -2335,7 +2363,7 @@ void target_vvm::proc_case_fun(ostream&os, const NetCase*net)
 		  continue;
 	    }
 
-	    string guard = emit_proc_rval(defn, 6, net->expr(idx));
+	    string guard = emit_proc_rval(defn, this, net->expr(idx));
 
 	    defn << "      if (B_IS1(" << test_func << "(" <<
 		  guard << "," << expr << "))) {" << endl;
@@ -2360,7 +2388,7 @@ void target_vvm::proc_condit(ostream&os, const NetCondit*net)
 	    return;
       }
 
-      string expr = emit_proc_rval(defn, 8, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
 
       unsigned if_step   = ++thread_step_;
       unsigned else_step = ++thread_step_;
@@ -2408,7 +2436,7 @@ void target_vvm::proc_condit(ostream&os, const NetCondit*net)
 
 void target_vvm::proc_condit_fun(ostream&os, const NetCondit*net)
 {
-      string expr = emit_proc_rval(defn, 8, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
 
       defn << "      // " << net->get_line() << ": conditional (if-else)"
 	   << endl;
@@ -2489,7 +2517,7 @@ bool target_vvm::proc_release(ostream&os, const NetRelease*dev)
 
 void target_vvm::proc_repeat(ostream&os, const NetRepeat*net)
 {
-      string expr = emit_proc_rval(defn, 8, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
       unsigned top_step = ++thread_step_;
       unsigned out_step = ++thread_step_;
 
@@ -2696,7 +2724,7 @@ void target_vvm::proc_while(ostream&os, const NetWhile*net)
       defn << "static bool " << thread_class_ << "_step_"
 	   << head_step << "_(vvm_thread*thr) {" << endl;
 
-      string expr = emit_proc_rval(defn, 8, net->expr());
+      string expr = emit_proc_rval(defn, this, net->expr());
 
       defn << "// " << net->expr()->get_line() <<
 	    ": test while condition." << endl;
@@ -2764,6 +2792,10 @@ extern const struct target tgt_vvm = {
 };
 /*
  * $Log: t-vvm.cc,v $
+ * Revision 1.145  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.144  2000/05/07 04:37:56  steve
  *  Carry strength values from Verilog source to the
  *  pform and netlist for gates.
diff --git a/vpi/sys_display.c b/vpi/sys_display.c
index 69f989e38..e64d186b2 100644
--- a/vpi/sys_display.c
+++ b/vpi/sys_display.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: sys_display.c,v 1.13 2000/04/21 02:00:35 steve Exp $"
+#ident "$Id: sys_display.c,v 1.14 2000/05/07 18:20:07 steve Exp $"
 #endif
 
 # include  "vpi_user.h"
@@ -55,7 +55,7 @@ static void array_from_iterator(struct strobe_cb_info*info, vpiHandle argv)
  * well so that I can look for arguments as I move forward through the
  * string.
  */
-static int format_str(char*fmt, int argc, vpiHandle*argv)
+static int format_str(unsigned int mcd, char*fmt, int argc, vpiHandle*argv)
 {
       s_vpi_value value;
       char buf[256];
@@ -73,7 +73,7 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
 			cnt = sizeof buf - 1;
 		  strncpy(buf, cp, cnt);
 		  buf[cnt] = 0;
-		  vpi_printf("%s", buf);
+		  vpi_mcd_printf(mcd, "%s", buf);
 		  cp += cnt;
 
 	    } else if (*cp == '%') {
@@ -90,14 +90,14 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
 		      case 'B':
 			value.format = vpiBinStrVal;
 			vpi_get_value(argv[idx++], &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 			cp += 1;
 			break;
 		      case 'd':
 		      case 'D':
 			value.format = vpiDecStrVal;
 			vpi_get_value(argv[idx++], &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 			cp += 1;
 			break;
 		      case 'h':
@@ -110,11 +110,11 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
 			}
 			value.format = vpiHexStrVal;
 			vpi_get_value(argv[idx++], &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 			cp += 1;
 			break;
 		      case 'm':
-			vpi_printf("%s", vpi_get_str(vpiFullName, argv[idx]));
+			vpi_mcd_printf(mcd, "%s", vpi_get_str(vpiFullName, argv[idx]));
 			idx += 1;
 			cp += 1;
 			break;
@@ -122,22 +122,22 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
 		      case 'O':
 			value.format = vpiOctStrVal;
 			vpi_get_value(argv[idx++], &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 			cp += 1;
 			break;
 		      case 't':
 		      case 'T':
 			value.format = vpiDecStrVal;
 			vpi_get_value(argv[idx++], &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 			cp += 1;
 			break;
 		      case '%':
-			vpi_printf("%%");
+			vpi_mcd_printf(mcd, "%%");
 			cp += 1;
 			break;
 		      default:
-			vpi_printf("%c", *cp);
+			vpi_mcd_printf(mcd, "%c", *cp);
 			cp += 1;
 			break;
 		  }
@@ -149,11 +149,11 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
 		      case 0:
 			break;
 		      case 'n':
-			vpi_printf("\n");
+			vpi_mcd_printf(mcd, "\n");
 			cp += 1;
 			break;
 		      default:
-			vpi_printf("%c", *cp);
+			vpi_mcd_printf(mcd, "%c", *cp);
 			cp += 1;
 		  }
 	    }
@@ -162,7 +162,7 @@ static int format_str(char*fmt, int argc, vpiHandle*argv)
       return idx;
 }
 
-static void do_display(struct strobe_cb_info*info)
+static void do_display(unsigned int mcd, struct strobe_cb_info*info)
 {
       s_vpi_value value;
       int idx;
@@ -173,20 +173,20 @@ static void do_display(struct strobe_cb_info*info)
 	    switch (vpi_get(vpiType, item)) {
 
 		case 0:
-		  vpi_printf(" ");
+		  vpi_mcd_printf(mcd, " ");
 		  break;
 
 		case vpiConstant:
 		  if (vpi_get(vpiConstType, item) == vpiStringConst) {
 			value.format = vpiStringVal;
 			vpi_get_value(item, &value);
-			idx += format_str(value.value.str,
+			idx += format_str(mcd, value.value.str,
 					  info->nitems-idx-1,
 					  info->items+idx+1);
 		  } else {
 			value.format = vpiBinStrVal;
 			vpi_get_value(item, &value);
-			vpi_printf("%s", value.value.str);
+			vpi_mcd_printf(mcd, "%s", value.value.str);
 		  }
 		  break;
 
@@ -195,17 +195,17 @@ static void do_display(struct strobe_cb_info*info)
 		case vpiMemoryWord:
 		  value.format = vpiBinStrVal;
 		  vpi_get_value(item, &value);
-		  vpi_printf("%s", value.value.str);
+		  vpi_mcd_printf(mcd, "%s", value.value.str);
 		  break;
 
 		case vpiTimeVar:
 		  value.format = vpiTimeVal;
 		  vpi_get_value(item, &value);
-		  vpi_printf("%u", value.value.time->low);
+		  vpi_mcd_printf(mcd, "%u", value.value.time->low);
 		  break;
 
 		default:
-		  vpi_printf("?");
+		  vpi_mcd_printf(mcd, "?");
 		  break;
 	    }
       }
@@ -220,7 +220,7 @@ static int sys_display_calltf(char *name)
 
       array_from_iterator(&info, argv);
 
-      do_display(&info);
+      do_display(1, &info);
 
       free(info.items);
 
@@ -242,7 +242,7 @@ static int strobe_cb(p_cb_data cb)
 {
       struct strobe_cb_info*info = (struct strobe_cb_info*)cb->user_data;
 
-      do_display(info);
+      do_display(1, info);
 
       vpi_printf("\n");
 
@@ -294,7 +294,7 @@ static vpiHandle *monitor_callbacks = 0;
 
 static int monitor_cb_2(p_cb_data cb)
 {
-      do_display(&monitor_info);
+      do_display(1, &monitor_info);
       vpi_printf("\n");
       monitor_scheduled = 0;
       return 0;
@@ -385,6 +385,126 @@ static int sys_monitor_calltf(char*name)
       return 0;
 }
 
+/*
+ * Implement the $fopen system function.
+ */
+static int sys_fopen_calltf(char *name)
+{
+      s_vpi_value val, value;
+
+      vpiHandle call_handle = vpi_handle(vpiSysTfCall, 0);
+      vpiHandle argv = vpi_iterate(vpiArgument, call_handle);
+      vpiHandle item = vpi_scan(argv);
+
+      if (item == 0) {
+	    vpi_printf("%s: file name parameter missing.\n", name);
+	    return 0;
+      }
+
+      if (vpi_get(vpiType, item) != vpiConstant) {
+	    vpi_printf("ERROR: %s parameter must be a constant\n", name);
+	    vpi_free_object(argv);
+	    return 0;
+      }
+
+      if (vpi_get(vpiConstType, item) != vpiStringConst) {
+	    vpi_printf("ERROR: %s parameter must be a constant\n", name);
+	    vpi_free_object(argv);
+	    return 0;
+      }
+
+      value.format = vpiStringVal;
+      vpi_get_value(item, &value);
+
+      val.format = vpiIntVal;
+      val.value.integer = vpi_mcd_open( value.value.str );
+
+      vpi_put_value(call_handle, &val, 0, vpiNoDelay);
+
+      return 0;
+}
+
+static int sys_fopen_sizetf(char*x)
+{
+      return 32;
+}
+
+/* Implement $fdisplay and $fwrite.  
+ * Perhaps this could be merged into sys_display_calltf.
+ */
+static int sys_fdisplay_calltf(char *name)
+{
+      struct strobe_cb_info info;
+      unsigned int mcd;
+      int type;
+      s_vpi_value value;
+      vpiHandle sys = vpi_handle(vpiSysTfCall, 0);
+      vpiHandle argv = vpi_iterate(vpiArgument, sys);
+      vpiHandle item = vpi_scan(argv);
+
+      if (item == 0) {
+	    vpi_printf("%s: mcd parameter missing.\n", name);
+	    return 0;
+      }
+
+      type = vpi_get(vpiType, item);
+      if (type != vpiReg && type != vpiReadVal) {
+	    vpi_printf("ERROR: %s mcd parameter must be of integral, got vpiType=%d\n",
+		       name, type);
+	    vpi_free_object(argv);
+	    return 0;
+      }
+
+      value.format = vpiIntVal;
+      vpi_get_value(item, &value);
+      mcd = value.value.integer;
+
+      array_from_iterator(&info, argv);
+      do_display(mcd, &info);
+      free(info.items);
+
+      if (strcmp(name,"$fdisplay") == 0)
+	    vpi_mcd_printf(mcd, "\n");
+
+      return 0;
+}
+
+
+/*
+ * Implement $fclose system function
+ */
+static int sys_fclose_calltf(char *name)
+{
+      unsigned int mcd;
+      int type;
+      s_vpi_value value;
+
+      vpiHandle sys = vpi_handle(vpiSysTfCall, 0);
+      vpiHandle argv = vpi_iterate(vpiArgument, sys);
+      vpiHandle item = vpi_scan(argv);
+
+      if (item == 0) {
+	    vpi_printf("%s: mcd parameter missing.\n", name);
+	    return 0;
+      }
+      type = vpi_get(vpiType, item);
+      if (type != vpiReg && type != vpiReadVal) {
+	    vpi_printf("ERROR: %s mcd parameter must be of integral type, got vpiType=%d\n",
+		       name, type);
+	    vpi_free_object(argv);
+	    return 0;
+      }
+
+      value.format = vpiIntVal;
+      vpi_get_value(item, &value);
+      mcd = value.value.integer;
+
+      vpi_printf("in fclose_calltf mcd=%d type=%d\n", mcd, value.format);
+      vpi_mcd_close(mcd);
+      return 0;
+}
+
+
 void sys_display_register()
 {
       s_vpi_systf_data tf_data;
@@ -420,11 +540,49 @@ void sys_display_register()
       tf_data.sizetf    = 0;
       tf_data.user_data = "$monitor";
       vpi_register_systf(&tf_data);
+
+      tf_data.type      = vpiSysFunc;
+      tf_data.tfname    = "$fopen";
+      tf_data.calltf    = sys_fopen_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf    = sys_fopen_sizetf;
+      tf_data.user_data = "$fopen";
+      vpi_register_systf(&tf_data);
+
+      tf_data.type      = vpiSysTask;
+      tf_data.tfname    = "$fclose";
+      tf_data.calltf    = sys_fclose_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf    = 0;
+      tf_data.user_data = "$fclose";
+      vpi_register_systf(&tf_data);
+
+      tf_data.type      = vpiSysTask;
+      tf_data.tfname    = "$fdisplay";
+      tf_data.calltf    = sys_fdisplay_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf    = 0;
+      tf_data.user_data = "$fdisplay";
+      vpi_register_systf(&tf_data);
+
+      tf_data.type      = vpiSysTask;
+      tf_data.tfname    = "$fwrite";
+      tf_data.calltf    = sys_fdisplay_calltf;
+      tf_data.compiletf = 0;
+      tf_data.sizetf    = 0;
+      tf_data.user_data = "$fwrite";
+      vpi_register_systf(&tf_data);
+
+      vpi_mcd_init();
 }
 
 
 /*
  * $Log: sys_display.c,v $
+ * Revision 1.14  2000/05/07 18:20:07  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.13  2000/04/21 02:00:35  steve
  *  exit if hex value is missing.
  *
diff --git a/vpi/vpi_user.h b/vpi/vpi_user.h
index 8d71306d4..3357809d9 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 1.15 2000/05/04 03:37:59 steve Exp $"
+#ident "$Id: vpi_user.h,v 1.16 2000/05/07 18:20:08 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -145,6 +145,11 @@ typedef struct t_vpi_value {
 extern void vpi_register_systf(const struct t_vpi_systf_data*ss);
 extern void vpi_printf(const char*fmt, ...);
 
+extern unsigned int vpi_mcd_close(unsigned int mcd);
+extern char *vpi_mcd_name(unsigned int mcd);
+extern unsigned int vpi_mcd_open(char *name);
+extern int vpi_mcd_printf(unsigned int mcd, const char*fmt, ...);
+
 /*
  * support for VPI callback functions.
  */
@@ -231,6 +236,10 @@ extern void (*vlog_startup_routines[])();
 
 /*
  * $Log: vpi_user.h,v $
+ * Revision 1.16  2000/05/07 18:20:08  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.15  2000/05/04 03:37:59  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.
diff --git a/vvm/Makefile.in b/vvm/Makefile.in
index b0de7bd26..9f5526acc 100644
--- a/vvm/Makefile.in
+++ b/vvm/Makefile.in
@@ -18,7 +18,7 @@
 #    59 Temple Place - Suite 330
 #    Boston, MA 02111-1307, USA
 #
-#ident "$Id: Makefile.in,v 1.29 2000/04/22 04:20:20 steve Exp $"
+#ident "$Id: Makefile.in,v 1.30 2000/05/07 18:20:08 steve Exp $"
 #
 #
 SHELL = /bin/sh
@@ -65,7 +65,8 @@ vvm_nexus.o vvm_pevent.o vvm_signal.o vvm_thread.o vvm_udp.o vpip.o
 
 P = vpi_bit.o vpi_callback.o \
 vpi_const.o vpi_iter.o vpi_memory.o vpi_null.o \
-vpi_priv.o vpi_scope.o vpi_signal.o vpi_simulation.o vpi_systask.o vpi_time.o
+vpi_priv.o vpi_scope.o vpi_signal.o vpi_simulation.o vpi_systask.o vpi_time.o \
+vpi_mcd.o
 
 libvvm.a: $O
 	rm -f $@
diff --git a/vvm/vpi_const.c b/vvm/vpi_const.c
index 436f468b5..c07e78cf0 100644
--- a/vvm/vpi_const.c
+++ b/vvm/vpi_const.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_const.c,v 1.7 2000/03/22 04:26:41 steve Exp $"
+#ident "$Id: vpi_const.c,v 1.8 2000/05/07 18:20:08 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -36,6 +36,7 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
       char*cp;
       unsigned val;
       unsigned idx;
+      int isx;
 
       cp = buff;
 
@@ -53,6 +54,8 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
 			*cp++ = 'x';
 		  }
 	    vp->format = vpiBinStrVal;
+	    *cp++ = 0;
+	    vp->value.str = buff;
 	    break;
 
 	  case vpiDecStrVal:
@@ -64,6 +67,8 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
 	    }
 	    sprintf(cp, "%u", val);
 	    cp += strlen(cp);
+	    *cp++ = 0;
+	    vp->value.str = buff;
 	    break;
 
 	  case vpiOctStrVal:
@@ -123,6 +128,8 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
 		  else
 			*cp++ = "01234567"[v];
 	    }
+	    *cp++ = 0;
+	    vp->value.str = buff;
 	    break;
 
 	  case vpiHexStrVal:
@@ -184,17 +191,36 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
 		  else
 			*cp++ = "0123456789abcdef"[v];
 	    }
+	    *cp++ = 0;
+	    vp->value.str = buff;
+	    break;
+
+	  case vpiIntVal:
+	    val = 0;
+	    isx = 0;
+	    for (idx = 0 ;  idx < nbits ;  idx += 1) {
+		  val *= 2;
+		  if (B_ISXZ(bits[nbits-idx-1]))
+			  isx = 1;
+		  else if (B_IS1(bits[nbits-idx-1]))
+			  val += 1;
+	    }
+	    if(isx)
+		    vp->value.integer = 0;
+	    else
+		    vp->value.integer = val;
 	    break;
 
 	  default:
 	    *cp++ = '(';
 	    *cp++ = '?';
 	    *cp++ = ')';
+	    *cp++ = 0;
+	    vp->format = vpiStringVal;
+	    vp->value.str = buff;
+
 	    break;
       }
-
-      *cp++ = 0;
-      vp->value.str = buff;
 }
 
 static int string_get(int code, vpiHandle ref)
@@ -291,6 +317,10 @@ vpiHandle vpip_make_number_const(struct __vpiNumberConst*ref,
 
 /*
  * $Log: vpi_const.c,v $
+ * Revision 1.8  2000/05/07 18:20:08  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.7  2000/03/22 04:26:41  steve
  *  Replace the vpip_bit_t with a typedef and
  *  define values for all the different bit
diff --git a/vvm/vpi_mcd.c b/vvm/vpi_mcd.c
new file mode 100644
index 000000000..c7b3d5568
--- /dev/null
+++ b/vvm/vpi_mcd.c
@@ -0,0 +1,123 @@
+/*
+ * Copyright (c) 2000 Stephen G. Tell <steve@telltronics.org>
+ *
+ *    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: vpi_mcd.c,v 1.1 2000/05/07 18:20:08 steve Exp $"
+#endif
+
+# include  "vpi_priv.h"
+# include  <assert.h>
+# include  <stdarg.h>
+# include  <stdio.h>
+# include  <stdlib.h>
+# include  <string.h>
+
+struct mcd_entry {
+	FILE *fp;
+	char *filename;
+};
+
+static struct mcd_entry mcd_table[32];
+
+/* Initialize mcd portion of vpi.  Must be called before
+ * any vpi_mcd routines can be used.
+ */
+void vpi_mcd_init()
+{
+	mcd_table[0].fp = stdout;
+	mcd_table[0].filename = "<stdout>";
+	mcd_table[1].fp = stderr;
+	mcd_table[1].filename = "<stderr>";
+	mcd_table[2].fp = stdout;  /* TODO: initialize this to log file */
+	mcd_table[2].filename = "<stdlog>";
+}
+
+/*
+ * close one or more channels.  we silently refuse to close the preopened ones.
+ */
+unsigned int vpi_mcd_close(unsigned int mcd)
+{
+	int i;
+	int rc;
+	rc = 0;
+	for(i = 3; i < 31; i++) {
+		if( ((mcd>>i) & 1) && mcd_table[i].filename) {
+			if(fclose(mcd_table[i].fp) != 0)
+				rc |= 1<<i;				
+			free(mcd_table[i].filename);
+			mcd_table[i].fp = NULL;
+			mcd_table[i].filename = NULL;
+		} else {
+			rc |= 1<<i;
+		}
+	}
+	return rc;
+}
+
+char *vpi_mcd_name(unsigned int mcd)
+{
+	int i;
+	for(i = 0; i < 31; i++) {
+		if( (mcd>>i) & 1)
+			return mcd_table[i].filename;
+	}
+	return NULL;
+}
+
+unsigned int vpi_mcd_open(char *name)
+{
+	int i;
+	for(i = 0; i < 31; i++) {
+		if(mcd_table[i].filename == NULL)
+			goto got_entry;
+	}
+	return 0;  /* too many open mcd's */
+
+got_entry:
+	mcd_table[i].fp = fopen(name, "w");
+	if(mcd_table[i].fp == NULL)
+		return 0;
+	mcd_table[i].filename = strdup(name);
+	return 1<<i;
+}
+
+int vpi_mcd_printf(unsigned int mcd, const char*fmt, ...)
+{
+	int i;
+	int len;
+	int rc;
+	va_list ap;
+
+	rc = len = 0;
+	va_start(ap, fmt);
+	for(i = 0; i < 31; i++) {
+		if( (mcd>>i) & 1) {
+			if(mcd_table[i].fp)
+				len = vfprintf(mcd_table[i].fp, fmt, ap);
+			else
+				rc = EOF;
+		}
+	}
+	va_end(ap);
+
+	if(rc)
+		return rc;
+	else
+		return len;
+}
+
diff --git a/vvm/vpi_priv.c b/vvm/vpi_priv.c
index 8f51ab785..63524bb4e 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 1.6 2000/05/04 03:37:59 steve Exp $"
+#ident "$Id: vpi_priv.c,v 1.7 2000/05/07 18:20:08 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -75,16 +75,15 @@ void vpip_calltask(const char*fname, unsigned nparms, vpiHandle*parms)
 /*
  * 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)
+void vpip_callfunc(const char*fname, unsigned nres, vpip_bit_t*res,
+		   unsigned nparms, vpiHandle*parms)
 {
       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.args  = parms;
+      cur_task.nargs = nparms;
       cur_task.res = res;
       cur_task.nres = nres;
 
@@ -220,6 +219,10 @@ void vpi_register_systf(const struct t_vpi_systf_data*systf)
 
 /*
  * $Log: vpi_priv.c,v $
+ * Revision 1.7  2000/05/07 18:20:08  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.6  2000/05/04 03:37:59  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.
diff --git a/vvm/vpi_priv.h b/vvm/vpi_priv.h
index b94579ecf..ce0f12069 100644
--- a/vvm/vpi_priv.h
+++ b/vvm/vpi_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_priv.h,v 1.17 2000/05/07 04:37:56 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.18 2000/05/07 18:20:08 steve Exp $"
 #endif
 
 /*
@@ -305,7 +305,8 @@ 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_callfunc(const char*name, unsigned nres, vpip_bit_t*res,
+			  unsigned nparms, vpiHandle*parms);
 
 extern void vpip_run_value_changes(struct __vpiSignal*sig);
 
@@ -366,6 +367,10 @@ extern int vpip_finished();
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.18  2000/05/07 18:20:08  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.17  2000/05/07 04:37:56  steve
  *  Carry strength values from Verilog source to the
  *  pform and netlist for gates.
diff --git a/vvm/vpi_systask.c b/vvm/vpi_systask.c
index 9a8f4b4de..711d17cda 100644
--- a/vvm/vpi_systask.c
+++ b/vvm/vpi_systask.c
@@ -17,17 +17,22 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #if !defined(WINNT) && !defined(macintosh)
-#ident "$Id: vpi_systask.c,v 1.4 2000/05/04 03:37:59 steve Exp $"
+#ident "$Id: vpi_systask.c,v 1.5 2000/05/07 18:20:08 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
 # include  <stdlib.h>
 # include  <assert.h>
 
+/*
+ * the iter function only supports getting an iterator of the
+ * arguments. This works equally well for tasks and functions.
+ */
 static vpiHandle systask_iter(int type, vpiHandle ref)
 {
       struct __vpiSysTaskCall*rfp = (struct __vpiSysTaskCall*)ref;
-      assert(ref->vpi_type->type_code == vpiSysTaskCall);
+      assert((ref->vpi_type->type_code == vpiSysTaskCall)
+	     || (ref->vpi_type->type_code == vpiSysFuncCall));
 
       if (rfp->nargs == 0)
 	    return 0;
@@ -88,6 +93,10 @@ const struct __vpirt vpip_sysfunc_rt = {
 
 /*
  * $Log: vpi_systask.c,v $
+ * Revision 1.5  2000/05/07 18:20:08  steve
+ *  Import MCD support from Stephen Tell, and add
+ *  system function parameter support to the IVL core.
+ *
  * Revision 1.4  2000/05/04 03:37:59  steve
  *  Add infrastructure for system functions, move
  *  $time to that structure and add $random.