diff --git a/lib/parfait/integer.rb b/lib/parfait/integer.rb
index 8a15535b..25e8ad57 100644
--- a/lib/parfait/integer.rb
+++ b/lib/parfait/integer.rb
@@ -71,6 +71,7 @@ module Parfait
     #FIXME: this is "just" for compilation
     def initialize
       super
+      set_internal_word( Integer.integer_index , 0 )
     end
     def self.type_length
       1    # 0 type
@@ -80,6 +81,7 @@ module Parfait
     #FIXME: this is "just" for compilation
     def initialize
       super
+      set_internal_word( Integer.integer_index , 1 )
     end
     def self.type_length
       1    # 0 type
@@ -89,6 +91,7 @@ module Parfait
     #FIXME: this is "just" for compilation
     def initialize
       super
+      set_internal_word( Integer.integer_index , 0 )
     end
     def self.type_length
       1    # 0 type
diff --git a/lib/risc/interpreter.rb b/lib/risc/interpreter.rb
index 46ab0af5..32874ef6 100644
--- a/lib/risc/interpreter.rb
+++ b/lib/risc/interpreter.rb
@@ -266,7 +266,7 @@ module Risc
         set_instruction(nil)
         return false
       when :died
-        raise "Method #{@registers[:r1].to_string} not found for #{@registers[std_reg(:syscall_1)]}"
+        raise "Method #{@registers[:r1]} not found for #{@registers[std_reg(:syscall_1)]}"
       else
         raise "un-implemented syscall #{name}"
       end
@@ -274,6 +274,15 @@ module Risc
       true
     end
 
+    def get_sys_return
+      val = get_register( std_reg(:syscall_1) ) # syscalls return into syscall_1
+    end
+
+    def run_all
+      tick while(@instruction)
+      clock
+    end
+
     def handle_putstring
       # should test length, syscall_3  (syscall_1 is file_descriptor, ie stdout)
       str = get_register( std_reg(:syscall_2) )
diff --git a/test/mains/helper.rb b/test/mains/helper.rb
index 2a254feb..5296ecf5 100644
--- a/test/mains/helper.rb
+++ b/test/mains/helper.rb
@@ -69,7 +69,7 @@ module Mains
       interpreter.tick while(interpreter.instruction)
       saved_in = interpreter.std_reg(:saved_message)
       assert_equal Parfait::Message , interpreter.get_register(saved_in).class
-      ret = interpreter.get_register(interpreter.std_reg(:syscall_1))
+      ret = interpreter.get_sys_return
       puts "Interpret #{interpreter.stdout} #{ret}" if ENV["TEST_ARM"] == "DEBUG"
       return ret , interpreter.stdout
     end
diff --git a/test/parfait/test_integer.rb b/test/parfait/test_integer.rb
index 9b273a0d..fe708780 100644
--- a/test/parfait/test_integer.rb
+++ b/test/parfait/test_integer.rb
@@ -54,5 +54,20 @@ module Parfait
       assert_equal 33 , addr.value
     end
   end
-
+  class TrueTest < MiniTest::Test
+    def test_true
+      assert TrueClass.new
+    end
+    def test_set
+      tru = TrueClass.new
+      assert_equal 20 , tru.set_internal_word( Integer.integer_index , 20 )
+      assert_equal 20 , tru.get_internal_word( Integer.integer_index )
+    end
+    def test_get_true
+      assert_equal 1 , TrueClass.new.get_internal_word( Integer.integer_index )
+    end
+    def test_get_false
+      assert_equal 0 , FalseClass.new.get_internal_word( Integer.integer_index )
+    end
+  end
 end
diff --git a/test/risc/test_interpreter.rb b/test/risc/test_interpreter.rb
index 646b7da4..96330fde 100644
--- a/test/risc/test_interpreter.rb
+++ b/test/risc/test_interpreter.rb
@@ -38,6 +38,10 @@ module Risc
     def test_pos
       assert_equal 1 , @interpreter.clock
     end
+    def test_return_value
+      @interpreter.run_all
+      assert_equal 5 , @interpreter.get_sys_return
+    end
   end
   class TestInterpreterTicks < MiniTest::Test
     include Ticker
@@ -98,7 +102,7 @@ module Risc
     def test_tick_15 #more than a binary code worth
       15.times {@interpreter.tick}
     end
-    class TestInterpreterDies #< MiniTest::Test
+    class TestInterpreterDies < MiniTest::Test
       include Ticker
       def setup
         @string_input = as_main("random.call")