diff --git a/src/c/nucl.c b/src/c/nucl.c
index 05aa68721..c98efa429 100644
--- a/src/c/nucl.c
+++ b/src/c/nucl.c
@@ -850,24 +850,21 @@ nucl_append_dictionary(cl_object symbol, cl_object value)
 
 /* -- Default words --------------------------------------------------------- */
 
-cl_object nucl_word_print_frame(int narg) {
-  cl_object frame = nucl_stack_frame();
-  cl_index ssize = nucl_stack_size();
-  cl_object size = ecl_make_fixnum(ssize);
-  nucl_write_cstr("[");
-  nucl_write_object(size);
-  nucl_write_cstr("] ");
-  loop_across_frame_fifo(elt, frame) {
+cl_object nucl_word_print_dictionary(int narg) {
+  cl_env_ptr the_env = ecl_core.first_env;
+  cl_object dict = ECL_SYM_VAL(the_env, nucl_dt);
+  loop_across_stack_fifo(elt, dict) {
     nucl_write_object(elt);
     nucl_write_cstr(" ");
-  } end_loop_across_frame();
-  return size;
+  } end_loop_across_stack();
+  return ECL_NIL;
 }
 
 cl_object nucl_word_print_stack(int narg) {
   const cl_env_ptr the_env = ecl_process_env();
-  cl_index ssize = nucl_stack_size();
-  cl_object size = ecl_make_fixnum(ECL_STACK_INDEX(the_env));
+  cl_index ssize = ECL_STACK_INDEX(the_env);
+  /* the stack always has 0 at the beginning */
+  cl_object size = ecl_make_fixnum(ssize);
   cl_object *ptr;
   nucl_write_cstr("[");
   nucl_write_object(size);
@@ -881,24 +878,15 @@ cl_object nucl_word_print_stack(int narg) {
   return size;
 }
 
-cl_object nucl_word_print_dictionary(int narg) {
-  cl_env_ptr the_env = ecl_core.first_env;
-  cl_object dict = ECL_SYM_VAL(the_env, nucl_dt);
-  loop_across_stack_fifo(elt, dict) {
-    nucl_write_object(elt);
-    nucl_write_cstr(" ");
-  } end_loop_across_stack();
-  return ECL_NIL;
-}
-
-/* FIXME manipulate directly the stack. */
 cl_object nucl_word_pop_print(int narg) {
-  cl_index ssize = nucl_stack_size();
-  if(ssize == 0) {
+  const cl_env_ptr the_env = ecl_process_env();
+  cl_index ssize = ECL_STACK_INDEX(the_env);
+  /* INV the first element 0 is always present. */
+  if(ssize <= 1) {
     nucl_write_cstr("error: stack underflow");
     return ECL_NIL;
   } else {
-    cl_object elt = nucl_stack_pop();
+    cl_object elt = ECL_STACK_POP_UNSAFE(the_env);
     nucl_write_object(elt);
     nucl_write_cstr(" ");
     return elt;
@@ -906,11 +894,8 @@ cl_object nucl_word_pop_print(int narg) {
 }
 
 cl_object nucl_word_test(int narg) {
-  cl_env_ptr the_env = ecl_core.first_env;
-  cl_object elt = ecl_make_fixnum(ECL_STACK_INDEX(the_env));
-  nucl_write_object(elt);
-  nucl_write_cstr(" ");
-  return elt;
+  nucl_write_cstr("Test call\n");
+  return ECL_NIL;
 }
 
 ecl_def_function(_nucl_word_ps, nucl_word_print_stack, static, const);
@@ -930,10 +915,10 @@ static const cl_object _nucl_sym_fed = make_dict_entry(";", ECL_UNBOUND);
 static cl_object nucl_dictionary_default_entries[] = {
   _nucl_sym_def,
   _nucl_sym_fed,
-  make_dict_entry(",", _nucl_word_tt),
-  make_dict_entry(".", _nucl_word_dp),
-  make_dict_entry(".S", _nucl_word_ps),
   make_dict_entry(".D", _nucl_word_pd),
+  make_dict_entry(".S", _nucl_word_ps),
+  make_dict_entry(".", _nucl_word_dp),
+  make_dict_entry(",", _nucl_word_tt),
   NULL,
 };
 
@@ -1051,8 +1036,10 @@ cl_object nucl_process_token (cl_object token)
 
 cl_object nucl_process_command ()
 {
-  cl_object result = limited_reader(ECL_CODE_CHAR('\n'));
-  cl_object command;
+  cl_object result, command;
+  if (Null(get_definition_p())) open_nucl_frame();
+
+  result = limited_reader(ECL_CODE_CHAR('\n'));
   /* Processing of the command is straightforward. First we clean up the stack
      frame by moving it to a list, and then we process individual entries until.
      Complete definitions are not pushed back onto the stack, only words. */
@@ -1069,8 +1056,12 @@ cl_object nucl_process_command ()
   /* Now if we are in not in a middle of the definition compile anonymous word
      from the current stack and call it. Otherwise leave the stack be. */
   if(Null(get_definition_p())) {
+    const cl_env_ptr the_env = ecl_process_env();
+    struct ecl_stack_frame aux_frame[1];
+    cl_object frame = ecl_cast_ptr(cl_object, aux_frame);
     cl_object word = nucl_compile_definition();
-    cl_object frame = nucl_stack_frame();
+    close_nucl_frame();
+    ecl_stack_frame_open(the_env, frame, 0);
     ecl_interpret(frame, ECL_NIL, word);
   }
   return result;
@@ -1085,8 +1076,6 @@ void nucl_repl (void)
   init_nucl_reader();
   init_nucl_dictionary();
   init_nucl_dictionary_entries();
-
-  cl_object frame = open_nucl_frame(); /* top level frame */
   do {
     if(Null(get_definition_p()))
       nucl_write_cstr("nucl> ");
@@ -1096,7 +1085,6 @@ void nucl_repl (void)
     if(Null(get_definition_p()))
       nucl_write_cstr("... ok\n");
   } while(result != ECL_EOF);
-  close_nucl_frame();
   nucl_write_cstr("... bye\n");
 }