diff --git a/tgt-vvp/vvp_process.c b/tgt-vvp/vvp_process.c
index 812447b93..f319ccfa2 100644
--- a/tgt-vvp/vvp_process.c
+++ b/tgt-vvp/vvp_process.c
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vvp_process.c,v 1.104 2005/03/06 17:07:48 steve Exp $"
+#ident "$Id: vvp_process.c,v 1.105 2005/03/22 05:18:34 steve Exp $"
 #endif
 
 # include  "vvp_priv.h"
@@ -85,24 +85,23 @@ static void set_to_lvariable(ivl_lval_t lval,
 		 a bit-select leval. Presumably, the x0 index register
 		 has been loaded wit the result of the evaluated
 		 ivl_lval_mux expression. */
-	    assert(wid == 1);
 
 	    draw_eval_expr_into_integer(ivl_lval_mux(lval), 0);
 	    fprintf(vvp_out, "    %%jmp/1 t_%u, 4;\n", skip_set);
 
-	    fprintf(vvp_out, "    %%set/x0 V_%s, %u;\n",
-		    vvp_signal_label(sig), bit);
+	    fprintf(vvp_out, "    %%set/x0 V_%s, %u, %u;\n",
+		    vvp_signal_label(sig), bit, wid);
 	    fprintf(vvp_out, "t_%u ;\n", skip_set);
 
       } else if (part_off > 0) {
 	      /* There is no mux expression, but a constant part
 		 offset. Load that into index x0 and generate a
 		 single-bit set instruction. */
-	    assert(wid == 1);
+	    assert(ivl_lval_width(lval) == wid);
 
 	    fprintf(vvp_out, "    %%ix/load 0, %u;\n", part_off);
-	    fprintf(vvp_out, "    %%set/x0 V_%s, %u;\n",
-		    vvp_signal_label(sig), bit);
+	    fprintf(vvp_out, "    %%set/x0 V_%s, %u, %u;\n",
+		    vvp_signal_label(sig), bit, wid);
 
       } else {
 	    fprintf(vvp_out, "    %%set/v V_%s, %u, %u;\n",
@@ -1469,6 +1468,9 @@ int draw_func_definition(ivl_scope_t scope)
 
 /*
  * $Log: vvp_process.c,v $
+ * Revision 1.105  2005/03/22 05:18:34  steve
+ *  The indexed set can write a vector, not just a bit.
+ *
  * Revision 1.104  2005/03/06 17:07:48  steve
  *  Non blocking assign to memory words.
  *
diff --git a/vvp/compile.cc b/vvp/compile.cc
index a10865aab..1ba004f33 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 1.194 2005/03/19 06:23:49 steve Exp $"
+#ident "$Id: compile.cc,v 1.195 2005/03/22 05:18:34 steve Exp $"
 #endif
 
 # include  "arith.h"
@@ -150,7 +150,7 @@ const static struct opcode_table_s opcode_table[] = {
       { "%set/mv", of_SET_MV, 3,  {OA_MEM_PTR,  OA_BIT1,     OA_BIT2} },
       { "%set/v",  of_SET_VEC,3,  {OA_FUNC_PTR, OA_BIT1,     OA_BIT2} },
       { "%set/wr", of_SET_WORDR,2,{OA_VPI_PTR,  OA_BIT1,     OA_NONE} },
-      { "%set/x0", of_SET_X0, 2,  {OA_FUNC_PTR, OA_BIT1,     OA_NONE} },
+      { "%set/x0", of_SET_X0, 3,  {OA_FUNC_PTR, OA_BIT1,     OA_BIT2} },
 //    { "%set/x0/x",of_SET_X0_X,3,{OA_FUNC_PTR, OA_BIT1,     OA_BIT2} },
       { "%shiftl/i0", of_SHIFTL_I0, 2, {OA_BIT1,OA_NUMBER,   OA_NONE} },
       { "%shiftr/i0", of_SHIFTR_I0, 2, {OA_BIT1,OA_NUMBER,   OA_NONE} },
@@ -1587,6 +1587,9 @@ void compile_param_string(char*label, char*name, char*str, char*value)
 
 /*
  * $Log: compile.cc,v $
+ * Revision 1.195  2005/03/22 05:18:34  steve
+ *  The indexed set can write a vector, not just a bit.
+ *
  * Revision 1.194  2005/03/19 06:23:49  steve
  *  Handle LPM shifts.
  *
diff --git a/vvp/opcodes.txt b/vvp/opcodes.txt
index d64c7ae5a..7d64dd0fc 100644
--- a/vvp/opcodes.txt
+++ b/vvp/opcodes.txt
@@ -1,7 +1,7 @@
 /*
  * Copyright (c) 2001-2003 Stephen Williams (steve@icarus.com)
  *
- *  $Id: opcodes.txt,v 1.61 2005/03/03 04:33:10 steve Exp $
+ *  $Id: opcodes.txt,v 1.62 2005/03/22 05:18:34 steve Exp $
  */
 
 
@@ -538,18 +538,20 @@ into index register 3.
 
 This instruction writes a real word to the specified VPI-like object.
 
-* %set/x0 <var-label>, <bit>
+* %set/x0 <var-label>, <bit>, <wid>
 
-This sets the bit of a signal vector, the address calculated by
-using the index register 0 to index the bit within the vector of
+This sets the part of a signal vector, the address calculated by
+using the index register 0 to index the base within the vector of
 <var-label>. The destination must be a signal of some sort. Otherwise,
 the instrution will fail.
 
-If the index value in index register is <0 (for example if %ix/get
-converted an unknown value into the register) then the set is not
-performed. Also, if the index value is beyond the width of the target
-signal, then the set is not performed. The instruction gets the
-dimensions of the target signal from the signal itself.
+The addressing is cannonical (0-based) so the compiler must figure out
+non-zero offsets, if any. The width is the width of the part being
+written. The other bits of the vector are not touched.
+
+The index may be signed, and if less then 0, the beginning bits are
+not assigned. Also, if the bits go beyond the end of the signal, those
+bits are not written anywhere.
 
 
 * %shiftl/i0 <bit>, <wid>
diff --git a/vvp/vthread.cc b/vvp/vthread.cc
index faca3d1b7..eb0be7396 100644
--- a/vvp/vthread.cc
+++ b/vvp/vthread.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vthread.cc,v 1.132 2005/03/06 17:07:48 steve Exp $"
+#ident "$Id: vthread.cc,v 1.133 2005/03/22 05:18:34 steve Exp $"
 #endif
 
 # include  "config.h"
@@ -2729,39 +2729,49 @@ bool of_SET_WORDR(vthread_t thr, vvp_code_t cp)
 /*
  * Implement the %set/x instruction:
  *
- *      %set/x <functor>, <bit>
+ *      %set/x <functor>, <bit>, <wid>
  *
- * The single bit goes into the indexed functor. Abort the instruction
- * if the index is outside the target vector dimensions. Get the
- * target vector dimensions from the vvp_fun_signal addressed by the
- * vvp_net pointer.
+ * The bit value of a vector go into the addressed functor. Do not
+ * transfer bits that are outside the signal range. Get the target
+ * vector dimensions from the vvp_fun_signal addressed by the vvp_net
+ * pointer.
  */
 bool of_SET_X0(vthread_t thr, vvp_code_t cp)
 {
       vvp_net_t*net = cp->net;
-      vvp_bit4_t bit_val = thr_get_bit(thr, cp->bit_idx[0]);
+      unsigned bit = cp->bit_idx[0];
+      unsigned wid = cp->bit_idx[1];
 
 	// Implicitly, we get the base into the target vector from the
 	// X0 register.
-      long idx = thr->words[0].w_int;
+      long index = thr->words[0].w_int;
 
       vvp_fun_signal*sig = dynamic_cast<vvp_fun_signal*> (net->fun);
 
-	/* If idx < 0, then the index value is probably generated from
-	   an undefined value. At any rate, this is defined to have no
-	   effect so quit now. */
-      if (idx < 0)
+      if (index < 0 && (wid <= (unsigned)-index))
 	    return true;
 
-      if ((unsigned)idx >= sig->size())
+      if (index >= (long)sig->size())
 	    return true;
 
-	// Make a 1-bit vector that will go to the target
-      vvp_vector4_t bit (1);
-      bit.set_bit(0, bit_val);
+      if (index < 0) {
+	    wid -= (unsigned) -index;
+	    index = 0;
+      }
+
+      if (index+wid > sig->size())
+	    wid = sig->size() - index;
+
+      vvp_vector4_t bit_vec(wid);
+      for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
+	    vvp_bit4_t bit_val = thr_get_bit(thr, bit);
+	    bit_vec.set_bit(idx, bit_val);
+	    if (bit >= 4)
+		  bit += 1;
+      }
 
       vvp_net_ptr_t ptr (net, 0);
-      vvp_send_vec4_pv(ptr, bit, idx, 1, sig->size());
+      vvp_send_vec4_pv(ptr, bit_vec, index, wid, sig->size());
 
       return true;
 }
@@ -3114,6 +3124,9 @@ bool of_JOIN_UFUNC(vthread_t thr, vvp_code_t cp)
 
 /*
  * $Log: vthread.cc,v $
+ * Revision 1.133  2005/03/22 05:18:34  steve
+ *  The indexed set can write a vector, not just a bit.
+ *
  * Revision 1.132  2005/03/06 17:07:48  steve
  *  Non blocking assign to memory words.
  *