diff --git a/vvp/README.txt b/vvp/README.txt
index fe941d9dc..94a6a9326 100644
--- a/vvp/README.txt
+++ b/vvp/README.txt
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
  *
- *  $Id: README.txt,v 1.76 2006/03/08 05:29:42 steve Exp $
+ *  $Id: README.txt,v 1.77 2006/03/18 22:51:10 steve Exp $
  */
 
 VVP SIMULATION ENGINE
@@ -102,8 +102,8 @@ objects.
 The syntax of a parameter is:
 
 	<label> .param/str <name>, <value>;
-	<label> .param/b <name>, <value> [<msb>,<lsb>,<s>];
-	<label> .param/l <name>, <value> [<msb>,<lsb>,<s>];
+	<label> .param/b <name>, <value> [<msb>,<lsb>];
+	<label> .param/l <name>, <value> [<msb>,<lsb>];
 	<label> .param/r <name>, <value>;
 
 The <name> is a string that names the parameter. The name is placed in
@@ -119,6 +119,9 @@ The value, then, is appropriate for the data type. For example:
 
 	P_123 .param/str "hello", "Hello, World.";
 
+The boolean and logic values can also be signed or not. If signed, the
+value is preceeded by a '+' character. (Note that the value is 2s
+compliment, so the '+' says only that it is signed, not positive.)
 
 FUNCTOR STATEMENTS:
 
diff --git a/vvp/compile.cc b/vvp/compile.cc
index cde6695b8..298f7728c 100644
--- a/vvp/compile.cc
+++ b/vvp/compile.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: compile.cc,v 1.218 2006/03/08 05:29:42 steve Exp $"
+#ident "$Id: compile.cc,v 1.219 2006/03/18 22:51:10 steve Exp $"
 #endif
 
 # include  "arith.h"
@@ -1473,10 +1473,10 @@ void compile_thread(char*start_sym, char*flag)
 	    free(flag);
 }
 
-void compile_param_logic(char*label, char*name, char*value)
+void compile_param_logic(char*label, char*name, char*value, bool signed_flag)
 {
       vvp_vector4_t value4 = c4string_to_vector4(value);
-      vpiHandle obj = vpip_make_binary_param(name, value4);
+      vpiHandle obj = vpip_make_binary_param(name, value4, signed_flag);
       compile_vpi_symbol(label, obj);
       vpip_attach_to_current_scope(obj);
 
@@ -1495,6 +1495,9 @@ void compile_param_string(char*label, char*name, char*value)
 
 /*
  * $Log: compile.cc,v $
+ * Revision 1.219  2006/03/18 22:51:10  steve
+ *  Syntax for carrying sign with parameter.
+ *
  * Revision 1.218  2006/03/08 05:29:42  steve
  *  Add support for logic parameters.
  *
diff --git a/vvp/compile.h b/vvp/compile.h
index bb3683801..0247a35e0 100644
--- a/vvp/compile.h
+++ b/vvp/compile.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: compile.h,v 1.79 2006/03/08 05:29:42 steve Exp $"
+#ident "$Id: compile.h,v 1.80 2006/03/18 22:51:10 steve Exp $"
 #endif
 
 # include  <stdio.h>
@@ -183,7 +183,8 @@ extern void compile_vpi_symbol(const char*label, vpiHandle obj);
 extern void compile_vpi_lookup(vpiHandle *objref, char*label);
 
 extern void compile_param_string(char*label, char*name, char*value);
-extern void compile_param_logic(char*label, char*name, char*value);
+extern void compile_param_logic(char*label, char*name, char*value,
+				bool signed_flag);
 
 /*
  * This function schedules a lookup of an indexed label. The ref
@@ -342,6 +343,9 @@ extern void compile_alias_real(char*label, char*name,
 
 /*
  * $Log: compile.h,v $
+ * Revision 1.80  2006/03/18 22:51:10  steve
+ *  Syntax for carrying sign with parameter.
+ *
  * Revision 1.79  2006/03/08 05:29:42  steve
  *  Add support for logic parameters.
  *
diff --git a/vvp/parse.y b/vvp/parse.y
index 1f4c57eb3..ad7f8f852 100644
--- a/vvp/parse.y
+++ b/vvp/parse.y
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: parse.y,v 1.81 2006/03/08 05:29:42 steve Exp $"
+#ident "$Id: parse.y,v 1.82 2006/03/18 22:51:10 steve Exp $"
 #endif
 
 # include  "parse_misc.h"
@@ -502,7 +502,10 @@ statement
 		{ compile_param_string($1, $3, $5); }
 
 	| T_LABEL K_PARAM_L T_STRING ',' T_SYMBOL ';'
-		{ compile_param_logic($1, $3, $5); }
+		{ compile_param_logic($1, $3, $5, false); }
+
+	| T_LABEL K_PARAM_L T_STRING ',' '+' T_SYMBOL ';'
+		{ compile_param_logic($1, $3, $6, true); }
 
   /* Oh and by the way, empty statements are OK as well. */
 
@@ -736,6 +739,9 @@ int compile_design(const char*path)
 
 /*
  * $Log: parse.y,v $
+ * Revision 1.82  2006/03/18 22:51:10  steve
+ *  Syntax for carrying sign with parameter.
+ *
  * Revision 1.81  2006/03/08 05:29:42  steve
  *  Add support for logic parameters.
  *
diff --git a/vvp/vpi_const.cc b/vvp/vpi_const.cc
index a31183248..e5342e3f6 100644
--- a/vvp/vpi_const.cc
+++ b/vvp/vpi_const.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_const.cc,v 1.34 2006/03/08 05:29:42 steve Exp $"
+#ident "$Id: vpi_const.cc,v 1.35 2006/03/18 22:51:10 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -329,6 +329,7 @@ vpiHandle vpip_make_binary_const(unsigned wid, char*bits)
       obj->base.vpi_type = &vpip_binary_rt;
 
       obj->signed_flag = 0;
+      obj->sized_flag = 0;
       obj->bits = vvp_vector4_t(wid);
 
       const char*bp = bits;
@@ -412,13 +413,15 @@ static const struct __vpirt vpip_binary_param_rt = {
       0
 };
 
-vpiHandle vpip_make_binary_param(char*name, const vvp_vector4_t&bits)
+vpiHandle vpip_make_binary_param(char*name, const vvp_vector4_t&bits,
+				 bool signed_flag)
 {
       struct __vpiBinaryParam*obj = new __vpiBinaryParam;
 
       obj->base.vpi_type = &vpip_binary_param_rt;
       obj->bits = bits;
-      obj->signed_flag = 0;
+      obj->signed_flag = signed_flag? 1 : 0;
+      obj->sized_flag = 0;
       obj->basename = name;
       obj->scope = vpip_peek_current_scope();
 
@@ -528,6 +531,9 @@ vpiHandle vpip_make_dec_const(int value)
 
 /*
  * $Log: vpi_const.cc,v $
+ * Revision 1.35  2006/03/18 22:51:10  steve
+ *  Syntax for carrying sign with parameter.
+ *
  * Revision 1.34  2006/03/08 05:29:42  steve
  *  Add support for logic parameters.
  *
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 1acf3e07e..d636f7414 100644
--- a/vvp/vpi_priv.h
+++ b/vvp/vpi_priv.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_priv.h,v 1.69 2006/03/08 05:29:42 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.70 2006/03/18 22:51:10 steve Exp $"
 #endif
 
 # include  "vpi_user.h"
@@ -291,11 +291,15 @@ vpiHandle vpip_make_string_param(char*name, char*value);
 struct __vpiBinaryConst {
       struct __vpiHandle base;
       vvp_vector4_t bits;
-      unsigned signed_flag :1;
+	/* TRUE if this constant is signed. */
+      int signed_flag :1;
+	/* TRUE if this constant has an explicit size (i.e. 19'h0 vs. 'h0) */
+      int sized_flag   :1;
 };
 
 vpiHandle vpip_make_binary_const(unsigned wid, char*bits);
-vpiHandle vpip_make_binary_param(char*name, const vvp_vector4_t&bits);
+vpiHandle vpip_make_binary_param(char*name, const vvp_vector4_t&bits,
+				 bool signed_flag);
 
 struct __vpiDecConst {
       struct __vpiHandle base;
@@ -428,6 +432,9 @@ extern char *need_result_buf(unsigned cnt, vpi_rbuf_t type);
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.70  2006/03/18 22:51:10  steve
+ *  Syntax for carrying sign with parameter.
+ *
  * Revision 1.69  2006/03/08 05:29:42  steve
  *  Add support for logic parameters.
  *