diff --git a/vpi/vpi_user.h b/vpi/vpi_user.h
index 3357809d9..e6cec9767 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 1.16 2000/05/07 18:20:08 steve Exp $"
+#ident "$Id: vpi_user.h,v 1.17 2000/05/18 03:27:32 steve Exp $"
 #endif
 
 #ifdef __cplusplus
@@ -86,7 +86,7 @@ typedef struct t_vpi_value {
 #define vpiOctStrVal    2
 #define vpiDecStrVal    3
 #define vpiHexStrVal    4
-#define vpiScalerVal    5
+#define vpiScalarVal    5
 #define vpiIntVal       6
 #define vpiReadVal      7
 #define vpiStringVal    8
@@ -97,6 +97,16 @@ typedef struct t_vpi_value {
 #define vpiSuppressVal 13
 
 
+/* SCALAR VALUES */
+#define vpi0 0
+#define vpi1 1
+#define vpiZ 2
+#define vpiX 3
+#define vpiH 4
+#define vpiL 5
+#define vpiDontCare 6
+
+
 /* OBJECT CODES */
 #define vpiConstant     7
 #define vpiFunction    20
@@ -236,6 +246,9 @@ extern void (*vlog_startup_routines[])();
 
 /*
  * $Log: vpi_user.h,v $
+ * Revision 1.17  2000/05/18 03:27:32  steve
+ *  Support writing scalars and vectors to signals.
+ *
  * 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.
diff --git a/vvm/vpi_const.c b/vvm/vpi_const.c
index c07e78cf0..62e657aea 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 1.8 2000/05/07 18:20:08 steve Exp $"
+#ident "$Id: vpi_const.c,v 1.9 2000/05/18 03:27:32 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -223,6 +223,60 @@ void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
       }
 }
 
+void vpip_bits_set_value(vpip_bit_t*bits, unsigned nbits, s_vpi_value*vp)
+{
+      switch (vp->format) {
+
+	  case vpiScalarVal:
+	    switch (vp->value.scalar) {
+		case vpi0:
+		  bits[0] = St0;
+		  break;
+		case vpi1:
+		  bits[0] = St1;
+		  break;
+		case vpiX:
+		  bits[1] = StX;
+		  break;
+		case vpiZ:
+		  bits[0] = HiZ;
+		  break;
+		default:
+		  assert(0);
+	    }
+	    break;
+
+	  case vpiVectorVal: {
+		unsigned long aval = vp->value.vector->aval;
+		unsigned long bval = vp->value.vector->bval;
+		int idx;
+		for (idx = 0 ;  idx < nbits ;  idx += 1) {
+		      int bit = (aval&1) | ((bval<<1)&2);
+		      switch (bit) {
+			  case 0:
+			    bits[idx] = St0;
+			    break;
+			  case 1:
+			    bits[idx] = St1;
+			    break;
+			  case 2:
+			    bits[idx] = HiZ;
+			    break;
+			  case 3:
+			    bits[idx] = StX;
+			    break;
+		      }
+		      aval >>= 1;
+		      bval >>= 1;
+		}
+		break;
+	  }
+
+	  default:
+	    assert(0);
+      }
+}
+
 static int string_get(int code, vpiHandle ref)
 {
       struct __vpiStringConst*rfp = (struct __vpiStringConst*)ref;
@@ -317,6 +371,9 @@ vpiHandle vpip_make_number_const(struct __vpiNumberConst*ref,
 
 /*
  * $Log: vpi_const.c,v $
+ * Revision 1.9  2000/05/18 03:27:32  steve
+ *  Support writing scalars and vectors to signals.
+ *
  * 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.
diff --git a/vvm/vpi_priv.h b/vvm/vpi_priv.h
index ae73600be..39c9997ef 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 1.20 2000/05/11 01:37:33 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.21 2000/05/18 03:27:32 steve Exp $"
 #endif
 
 /*
@@ -113,6 +113,8 @@ extern vpip_bit_t vpip_bits_resolve(const vpip_bit_t*bits, unsigned nbits);
 
 extern void vpip_bits_get_value(vpip_bit_t*bits, unsigned nbits,
 				s_vpi_value*vp);
+extern void vpip_bits_set_value(vpip_bit_t*bits, unsigned nbits,
+				s_vpi_value*vp);
 
 /*
  * This structure is the very base of a vpiHandle. Every handle
@@ -377,6 +379,9 @@ extern int vpip_finished();
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.21  2000/05/18 03:27:32  steve
+ *  Support writing scalars and vectors to signals.
+ *
  * Revision 1.20  2000/05/11 01:37:33  steve
  *  Calculate the X output value from drive0 and drive1
  *
diff --git a/vvm/vpi_signal.c b/vvm/vpi_signal.c
index c52a83634..0d642036e 100644
--- a/vvm/vpi_signal.c
+++ b/vvm/vpi_signal.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_signal.c,v 1.9 2000/03/31 07:08:39 steve Exp $"
+#ident "$Id: vpi_signal.c,v 1.10 2000/05/18 03:27:32 steve Exp $"
 #endif
 
 # include  "vpi_priv.h"
@@ -65,12 +65,22 @@ static void signal_get_value(vpiHandle ref, s_vpi_value*vp)
       vpip_bits_get_value(rfp->bits, rfp->nbits, vp);
 }
 
+static void signal_put_value(vpiHandle ref, s_vpi_value*vp,
+			     p_vpi_time when, int flags)
+{
+      struct __vpiSignal*rfp = (struct __vpiSignal*)ref;
+      assert((ref->vpi_type->type_code==vpiNet)
+	     || (ref->vpi_type->type_code==vpiReg));
+
+      vpip_bits_set_value(rfp->bits, rfp->nbits, vp);
+}
+
 static const struct __vpirt vpip_net_rt = {
       vpiNet,
       signal_get,
       signal_get_str,
       signal_get_value,
-      0,
+      signal_put_value,
       0,
       0
 };
@@ -92,7 +102,7 @@ static const struct __vpirt vpip_reg_rt = {
       signal_get,
       signal_get_str,
       signal_get_value,
-      0,
+      signal_put_value,
       0,
       0
 };
@@ -111,6 +121,9 @@ vpiHandle vpip_make_reg(struct __vpiSignal*ref, const char*name,
 
 /*
  * $Log: vpi_signal.c,v $
+ * Revision 1.10  2000/05/18 03:27:32  steve
+ *  Support writing scalars and vectors to signals.
+ *
  * Revision 1.9  2000/03/31 07:08:39  steve
  *  allow cancelling of cbValueChange events.
  *