diff --git a/vvp/draw_tt.c b/vvp/draw_tt.c
index ec78cee68..9635326a1 100644
--- a/vvp/draw_tt.c
+++ b/vvp/draw_tt.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: draw_tt.c,v 1.19 2005/02/12 22:50:52 steve Exp $"
+#ident "$Id: draw_tt.c,v 1.20 2005/02/12 23:05:25 steve Exp $"
 #endif
 
 # include  <stdio.h>
@@ -153,7 +153,7 @@ static void draw_BUFZ(void)
       printf("};\n");
 }
 #endif
-
+#if 0
 static void draw_BUFIF0(void)
 {
       unsigned i0, i1, i2, i3;
@@ -187,7 +187,8 @@ static void draw_BUFIF0(void)
 
       printf("};\n");
 }
-
+#endif
+#if 0
 static void draw_BUFIF1(void)
 {
       unsigned i0, i1, i2, i3;
@@ -221,7 +222,7 @@ static void draw_BUFIF1(void)
 
       printf("};\n");
 }
-
+#endif
 static void draw_PMOS(void)
 {
       unsigned i0, i1, i2, i3;
@@ -741,8 +742,6 @@ static void draw_oct_table()
 main()
 {
       printf("# include  \"logic.h\"\n");
-      draw_BUFIF0();
-      draw_BUFIF1();
       draw_PMOS();
       draw_NMOS();
       draw_MUXX();
@@ -762,6 +761,9 @@ main()
 
 /*
  * $Log: draw_tt.c,v $
+ * Revision 1.20  2005/02/12 23:05:25  steve
+ *  Cleanup unused truth tables.
+ *
  * Revision 1.19  2005/02/12 22:50:52  steve
  *  Implement the vvp_fun_muxz functor.
  *
diff --git a/vvp/logic.h b/vvp/logic.h
index eb6b02fd1..009eaea8c 100644
--- a/vvp/logic.h
+++ b/vvp/logic.h
@@ -19,7 +19,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: logic.h,v 1.12 2005/02/12 22:50:52 steve Exp $"
+#ident "$Id: logic.h,v 1.13 2005/02/12 23:05:25 steve Exp $"
 #endif
 
 # include  "vvp_net.h"
@@ -94,6 +94,13 @@ class vvp_fun_bufz: public vvp_net_fun_t {
 /*
  * The muxz functor is an A-B mux device, with the data inputs on
  * ports 0 and 1. port 2 is the select input.
+ *
+ * The select input must be 1 bit wide. If it is 0, then the port-0
+ * vector is passed out. If select is 1, then port-1 is passed
+ * out. Otherwise, a vector is passed out that reflects x?: behavior
+ * in verilog. The width of the blended output is the width of the largest
+ * input (port-0 or port-1) to enter the device. The narrow vector is
+ * padded with X values.
  */
 class vvp_fun_muxz : public vvp_net_fun_t {
 
@@ -111,12 +118,9 @@ class vvp_fun_muxz : public vvp_net_fun_t {
 
 // table functor types
 
-extern const unsigned char ft_BUFIF0[];
-extern const unsigned char ft_BUFIF1[];
 extern const unsigned char ft_PMOS[];
 extern const unsigned char ft_NMOS[];
 extern const unsigned char ft_MUXX[];
-extern const unsigned char ft_MUXZ[];
 extern const unsigned char ft_EEQ[];
 extern const unsigned char ft_NAND[];
 extern const unsigned char ft_NOR[];
@@ -130,8 +134,8 @@ extern const unsigned char ft_var[];
 
 /*
  * $Log: logic.h,v $
- * Revision 1.12  2005/02/12 22:50:52  steve
- *  Implement the vvp_fun_muxz functor.
+ * Revision 1.13  2005/02/12 23:05:25  steve
+ *  Cleanup unused truth tables.
  *
  * Revision 1.11  2005/01/29 17:52:06  steve
  *  move AND to buitin instead of table.