diff --git a/vvp/concat.cc b/vvp/concat.cc
new file mode 100644
index 000000000..d3ac727d6
--- /dev/null
+++ b/vvp/concat.cc
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2004-2005 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
+ */
+#ident "$Id: concat.cc,v 1.1 2005/01/22 00:01:09 steve Exp $"
+
+# include  "compile.h"
+# include  "vvp_net.h"
+# include  <stdlib.h>
+#ifdef HAVE_MALLOC_H
+# include  <malloc.h>
+#endif
+# include  <assert.h>
+
+
+vvp_fun_concat::vvp_fun_concat(unsigned w0, unsigned w1,
+			       unsigned w2, unsigned w3)
+: val_(w0+w1+w2+w3)
+{
+      wid_[0] = w0;
+      wid_[1] = w1;
+      wid_[2] = w2;
+      wid_[3] = w3;
+
+      for (unsigned idx = 0 ;  idx < val_.size() ;  idx += 1)
+	    val_.set_bit(idx, BIT4_X);
+}
+
+vvp_fun_concat::~vvp_fun_concat()
+{
+}
+
+void vvp_fun_concat::recv_vec4(vvp_net_ptr_t port, vvp_vector4_t bit)
+{
+      unsigned pdx = port.port();
+
+      assert(bit.size() == wid_[pdx]);
+
+      unsigned off = 0;
+      for (unsigned idx = 0 ;  idx < pdx ;  idx += 1)
+	    off += wid_[idx];
+
+      for (unsigned idx = 0 ;  idx < wid_[pdx] ;  idx += 1) {
+	    val_.set_bit(off+idx, bit.value(idx));
+      }
+
+      vvp_send_vec4(port.ptr()->out, val_);
+}
+
+void vvp_fun_concat::recv_vec8(vvp_net_ptr_t port, vvp_vector8_t bit)
+{
+      recv_vec4(port, reduce4(bit));
+}
+
+void compile_concat(char*label, unsigned w0, unsigned w1,
+		    unsigned w2, unsigned w3,
+		    unsigned argc, struct symb_s*argv)
+{
+      vvp_fun_concat*fun = new vvp_fun_concat(w0, w1, w2, w3);
+
+      vvp_net_t*net = new vvp_net_t;
+      net->fun = fun;
+
+      define_functor_symbol(label, net);
+      free(label);
+
+      inputs_connect(net, argc, argv);
+}
+
+
+/*
+ * $Log: concat.cc,v $
+ * Revision 1.1  2005/01/22 00:01:09  steve
+ *  Add missing concat.cc to cvs
+ *
+ */
+