diff --git a/vvp/stop.cc b/vvp/stop.cc
index 6d8db6d0f..92bca18c0 100644
--- a/vvp/stop.cc
+++ b/vvp/stop.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: stop.cc,v 1.2 2003/02/22 06:32:36 steve Exp $"
+#ident "$Id: stop.cc,v 1.3 2003/02/23 06:41:54 steve Exp $"
 #endif
 
 /*
@@ -43,25 +43,91 @@
 # include  <malloc.h>
 #endif
 
-static bool interact_flag = true;
+struct __vpiScope*stop_current_scope = 0;
 
-static void invoke_systf(const char*txt)
-{
-      printf("**** System invocation not supported yet.\n");
-}
+static bool interact_flag = true;
 
 static void cmd_call(unsigned argc, char*argv[])
 {
-      if (argc <= 1)
-	    return;
+      struct __vpiHandle**table;
+      unsigned ntable;
 
-      vpiHandle call_handle = vpip_build_vpi_call(argv[1], 0, 0, 0, 0);
-      if (call_handle == 0)
-	    return;
+      if (stop_current_scope == 0) {
+	    vpip_make_root_iterator(table, ntable);
 
-      vpip_execute_vpi_call(0, call_handle);
+      } else {
+	    table = stop_current_scope->intern;
+	    ntable = stop_current_scope->nintern;
+      }
 
-      vpi_free_object(call_handle);
+      unsigned vpi_argc = argc - 1;
+      vpiHandle*vpi_argv = (vpiHandle*)calloc(vpi_argc, sizeof(vpiHandle));
+
+      unsigned errors = 0;
+
+      for (unsigned idx = 0 ;  idx < vpi_argc ;  idx += 1) {
+	    vpiHandle handle = 0;
+
+	      /* Detect the special case that the argument is the
+		 .(dot) string. This represents the handle for the
+		 current scope. */
+	    if (stop_current_scope && (strcmp(argv[idx+1], ".") == 0))
+		  handle = &stop_current_scope->base;
+
+	      /* Try to find the vpiHandle within this scope that has
+		 the name in argv[idx+2]. Look in the current scope. */
+
+	    for (unsigned tmp = 0 ;  (tmp < ntable)&& !handle ;  tmp += 1) {
+		  struct __vpiScope*scope;
+		  struct __vpiSignal*sig;
+
+		  switch (table[tmp]->vpi_type->type_code) {
+
+		      case vpiModule:
+		      case vpiFunction:
+		      case vpiTask:
+		      case vpiNamedBegin:
+		      case vpiNamedFork:
+			scope = (struct __vpiScope*) table[idx];
+			if (strcmp(scope->name, argv[idx+1]) == 0)
+			      handle = table[tmp];
+			break;
+
+		      case vpiReg:
+		      case vpiNet:
+			sig = (struct __vpiSignal*) table[tmp];
+			if (strcmp(sig->name, argv[idx+1]) == 0)
+			      handle = table[tmp];
+			break;
+
+		  }
+	    }
+
+	    if (handle == 0) {
+		  printf("call error: I don't know how to"
+			 " pass %s to %s\n", argv[idx+1], argv[0]);
+		  errors += 1;
+	    }
+
+	    vpi_argv[idx] = handle;
+      }
+
+	/* If there are no errors so far, then make up a call to the
+	   vpi task and execute that call. Free the call structure
+	   when we finish. */
+      if (errors == 0) {
+	    vpiHandle call_handle = vpip_build_vpi_call(argv[0], 0, 0,
+							vpi_argc, vpi_argv);
+	    if (call_handle == 0) {
+		  free(vpi_argv);
+		  return;
+	    }
+
+	    vpip_execute_vpi_call(0, call_handle);
+	    vpi_free_object(call_handle);
+      }
+
+      free(vpi_argv);
 }
 
 static void cmd_cont(unsigned, char*[])
@@ -77,12 +143,125 @@ static void cmd_finish(unsigned, char*[])
 
 static void cmd_help(unsigned, char*[]);
 
+static void cmd_list(unsigned, char*[])
+{
+      struct __vpiHandle**table;
+      unsigned ntable;
+
+      if (stop_current_scope == 0) {
+	    vpip_make_root_iterator(table, ntable);
+
+      } else {
+	    table = stop_current_scope->intern;
+	    ntable = stop_current_scope->nintern;
+      }
+
+      printf("%u items in this scope:\n", ntable);
+      for (unsigned idx = 0 ;  idx < ntable ;  idx += 1) {
+
+	    struct __vpiScope*scope;
+	    struct __vpiSignal*sig;
+
+	    switch (table[idx]->vpi_type->type_code) {
+		case vpiModule:
+		  scope = (struct __vpiScope*) table[idx];
+		  printf("module  : %s\n", scope->name);
+		  break;
+
+		case vpiReg:
+		  sig = (struct __vpiSignal*) table[idx];
+		  if ((sig->msb == 0) && (sig->lsb == 0))
+			printf("reg     : %s%s\n", sig->name,
+			       sig->signed_flag? "signed " : "");
+		  else
+			printf("reg     : %s%s[%d:%d]\n", sig->name,
+			       sig->signed_flag? "signed " : "",
+			       sig->msb, sig->lsb);
+		  break;
+
+		default:
+		  printf("%8d: <vpi handle>\n",
+			 table[idx]->vpi_type->type_code);
+		  break;
+	    }
+
+      }
+}
+
+static void cmd_pop(unsigned, char*[])
+{
+      if (stop_current_scope != 0)
+	    stop_current_scope = stop_current_scope->scope;
+}
+
+static void cmd_push(unsigned argc, char* argv[])
+{
+
+      for (unsigned idx = 1 ;  idx < argc ;  idx += 1) {
+	    struct __vpiHandle**table;
+	    unsigned ntable;
+
+	    struct __vpiScope*child = 0;
+
+	    if (stop_current_scope) {
+		  table = stop_current_scope->intern;
+		  ntable = stop_current_scope->nintern;
+	    } else {
+		  vpip_make_root_iterator(table, ntable);
+	    }
+
+	    child = 0;
+	    unsigned tmp;
+	    for (tmp = 0 ;  tmp < ntable ;  tmp += 1) {
+		  if (table[tmp]->vpi_type->type_code != vpiModule)
+			continue;
+
+		  struct __vpiScope*cp = (struct __vpiScope*) table[tmp];
+
+		    /* This is a scope, and the name matches, then
+		       report that I found the child. */
+		  if (strcmp(cp->name, argv[idx]) == 0) {
+			child = cp;
+			break;
+		  }
+	    }
+
+	    if (child == 0) {
+		  printf("Scope %s not found.\n", argv[idx]);
+		  return;
+	    }
+
+	    stop_current_scope = child;
+      }
+}
+
 static void cmd_time(unsigned, char*[])
 {
       unsigned long ticks = schedule_simtime();
       printf("%lu ticks\n", ticks);
 }
 
+static void cmd_where(unsigned, char*[])
+{
+      struct __vpiScope*cur = stop_current_scope;
+
+      while (cur) {
+	    switch (cur->base.vpi_type->type_code) {
+		case vpiModule:
+		  printf("module %s\n",
+			 cur->name);
+		  break;
+		default:
+		  printf("scope (%d) %s;\n",
+			 cur->base.vpi_type->type_code,
+			 cur->name);
+		  break;
+	    }
+
+	    cur = cur->scope;
+      }
+}
+
 static void cmd_unknown(unsigned, char*argv[])
 {
       printf("Unknown command: %s\n", argv[0]);
@@ -95,16 +274,24 @@ struct {
       void (*proc)(unsigned argc, char*argv[]);
       const char*summary;
 } cmd_table[] = {
-      { "call",   &cmd_call,
-        "Call a system task"},
+      { "cd",     &cmd_push,
+        "Synonym for push."},
       { "cont",   &cmd_cont,
         "Resume (continue) the simulation"},
       { "finish", &cmd_finish,
         "Finish the simulation."},
-      { "help",  &cmd_help,
+      { "help",   &cmd_help,
         "Get help."},
+      { "list",   &cmd_list,
+        "List items in the current scope."},
+      { "pop",    &cmd_pop,
+        "Pop one scope from the scope stack."},
+      { "push",   &cmd_push,
+        "Descend into the named scope."},
       { "time",   &cmd_time,
         "Print the current simulation time."},
+      { "where",  &cmd_where,
+        "Show current scope, and scope hierarchy stack."},
       { 0,        &cmd_unknown, 0}
 };
 
@@ -116,9 +303,9 @@ static void cmd_help(unsigned argc, char*argv[])
 	    printf("%-8s - %s\n", cmd_table[idx].name, cmd_table[idx].summary);
       }
 
-      printf("\nIf the command starts with a dollar ($) character, it\n"
-	     "is taken instead to be a system task or function call\n"
-	     "and will be parsed and invoked accordingly.\n");
+      printf("\nIf the command name starts with a '$' character, it\n"
+	     "is taken to be the name of a system task, and a call is\n"
+	     "built up and executed.\n");
 }
 
 
@@ -139,14 +326,21 @@ static void invoke_command(char*txt)
 	    argc += 1;
       }
 
+
 	/* Look up the command, using argv[0] as the key. */
       if (argc > 0) {
-	    unsigned idx;
-	    for (idx = 0 ;  cmd_table[idx].name ;  idx += 1)
-		  if (strcmp(cmd_table[idx].name, argv[0]) == 0)
-			break;
 
-	    cmd_table[idx].proc (argc, argv);
+	    if (argv[0][0] == '$') {
+		  cmd_call(argc, argv);
+
+	    } else {
+		  unsigned idx;
+		  for (idx = 0 ;  cmd_table[idx].name ;  idx += 1)
+			if (strcmp(cmd_table[idx].name, argv[0]) == 0)
+			      break;
+
+		  cmd_table[idx].proc (argc, argv);
+	    }
       }
 
 
@@ -169,18 +363,7 @@ void stop_handler(int rc)
 	    while (*first && isspace(*first))
 		  first += 1;
 
-	      /* If the line starts with a $, then this is the
-		 invocation of a system task or system function, so
-		 call the invoke_systf function to handle
-		 it. Otherwise, this is a simple command, so invoke
-		 the command processor. */
-
-	    if (*first == '$') {
-		  invoke_systf(first);
-
-	    } else {
-		  invoke_command(first);
-	    }
+	    invoke_command(first);
 
 	    free(input);
       }
@@ -190,6 +373,11 @@ void stop_handler(int rc)
 
 /*
  * $Log: stop.cc,v $
+ * Revision 1.3  2003/02/23 06:41:54  steve
+ *  Add to interactive stop mode support for
+ *  current scope, the ability to scan/traverse
+ *  scopes, and the ability to call system tasks.
+ *
  * Revision 1.2  2003/02/22 06:32:36  steve
  *  Basic support for system task calls.
  *
diff --git a/vvp/vpi_priv.h b/vvp/vpi_priv.h
index 0216abd57..43c311486 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 1.48 2003/02/10 05:20:10 steve Exp $"
+#ident "$Id: vpi_priv.h,v 1.49 2003/02/23 06:41:54 steve Exp $"
 #endif
 
 # include  "vpi_user.h"
@@ -157,6 +157,8 @@ struct __vpiScope {
 extern struct __vpiScope* vpip_peek_current_scope(void);
 extern void vpip_attach_to_current_scope(vpiHandle obj);
 extern vpiHandle vpip_make_root_iterator(void);
+extern void vpip_make_root_iterator(struct __vpiHandle**&table,
+				    unsigned&ntable);
 
 /*
  * Signals include the variable types (reg, integer, time) and are
@@ -397,6 +399,11 @@ extern char *need_result_buf(unsigned cnt, vpi_rbuf_t type);
 
 /*
  * $Log: vpi_priv.h,v $
+ * Revision 1.49  2003/02/23 06:41:54  steve
+ *  Add to interactive stop mode support for
+ *  current scope, the ability to scan/traverse
+ *  scopes, and the ability to call system tasks.
+ *
  * Revision 1.48  2003/02/10 05:20:10  steve
  *  Add value change callbacks to real variables.
  *
diff --git a/vvp/vpi_scope.cc b/vvp/vpi_scope.cc
index 851973075..628fdb484 100644
--- a/vvp/vpi_scope.cc
+++ b/vvp/vpi_scope.cc
@@ -17,7 +17,7 @@
  *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
  */
 #ifdef HAVE_CVS_IDENT
-#ident "$Id: vpi_scope.cc,v 1.24 2003/02/11 05:20:45 steve Exp $"
+#ident "$Id: vpi_scope.cc,v 1.25 2003/02/23 06:41:54 steve Exp $"
 #endif
 
 # include  "compile.h"
@@ -43,6 +43,12 @@ vpiHandle vpip_make_root_iterator(void)
 				vpip_root_table_ptr, false);
 }
 
+void vpip_make_root_iterator(struct __vpiHandle**&table, unsigned&ntable)
+{
+      table = vpip_root_table_ptr;
+      ntable = vpip_root_table_cnt;
+}
+
 static bool handle_is_scope(vpiHandle obj)
 {
       return (obj->vpi_type->type_code == vpiModule)
@@ -448,6 +454,11 @@ void vpip_attach_to_current_scope(vpiHandle obj)
 
 /*
  * $Log: vpi_scope.cc,v $
+ * Revision 1.25  2003/02/23 06:41:54  steve
+ *  Add to interactive stop mode support for
+ *  current scope, the ability to scan/traverse
+ *  scopes, and the ability to call system tasks.
+ *
  * Revision 1.24  2003/02/11 05:20:45  steve
  *  Include vpiRealVar objects in vpiVariables scan.
  *