diff --git a/lib/mom/instruction/message_setup.rb b/lib/mom/instruction/message_setup.rb
index cc8a2fef..01989063 100644
--- a/lib/mom/instruction/message_setup.rb
+++ b/lib/mom/instruction/message_setup.rb
@@ -22,6 +22,7 @@ module Mom
     attr_reader :method_source
 
     def initialize(method_source)
+      raise "no nil" unless method_source
       @method_source = method_source
     end
 
diff --git a/lib/mom/instruction/resolve_method.rb b/lib/mom/instruction/resolve_method.rb
index f10bbd1c..4698046b 100644
--- a/lib/mom/instruction/resolve_method.rb
+++ b/lib/mom/instruction/resolve_method.rb
@@ -65,7 +65,7 @@ module Mom
         # temporary, need to raise really.
         factory! << Parfait.object_space.get_factory_for(:Integer)
         integer_tmp! << factory[:reserve]
-        Risc::Builtin::Object.emit_syscall( builder , :exit ) #uses integer_tmp
+        Mom::Builtin.emit_syscall( builder , :exit ) #uses integer_tmp
 
         add_code ok_label
         cache_entry[:cached_method] << callable_method
diff --git a/lib/risc/builder.rb b/lib/risc/builder.rb
index f75fb9fc..45726432 100644
--- a/lib/risc/builder.rb
+++ b/lib/risc/builder.rb
@@ -9,7 +9,7 @@ module Risc
   #  space << Parfait.object_space # load constant
   #  message[:receiver] << space  #make current message's (r0) receiver the space
   # See http://ruby-x.org/rubyx/builder.html for details
-  # 
+  #
   class Builder
 
     attr_reader :built , :compiler
diff --git a/lib/risc/position/position.rb b/lib/risc/position/position.rb
index e3159454..d3c4e915 100644
--- a/lib/risc/position/position.rb
+++ b/lib/risc/position/position.rb
@@ -186,7 +186,7 @@ module Risc
     # populate the position caches (forward and revese) with the given position
     # forward caches object -> position
     # reverse caches position.at > position
-    # Labels do not participatein reverse cache
+    # Labels do not participate in reverse cache
     def self.set_cache( position , to)
       postest = Position.positions[position.object] unless to < 0
       raise "Mismatch #{position}" if postest and postest != position
diff --git a/lib/rubyx/rubyx_compiler.rb b/lib/rubyx/rubyx_compiler.rb
index c3f28ce3..b41bf585 100644
--- a/lib/rubyx/rubyx_compiler.rb
+++ b/lib/rubyx/rubyx_compiler.rb
@@ -1,5 +1,14 @@
 module RubyX
-  # The RubyXCompiler provides the main interface to create binaries
+  # The RubyXCompiler provides the main interface to create binaries, and also
+  # give helper functions to create any intermediate layer.
+  # Layers are:
+  # - ruby , always needed as input, string
+  # - vool - intermediate language layer
+  # - mom - intermediate machine layer
+  # - risc - "last" intermediate machine layer
+  # - target - arm or interpreter binary code
+  # - binary - "linked" code, everything need to create an elf binary
+  #
   #
   # There are methods to go from ruby to any of the layers in the system
   # (mainly for testing). ruby_to_binary creates actual binary code
@@ -38,42 +47,59 @@ module RubyX
       to_binary(platform)
     end
 
-    # Process previously stored vool source to binary.
-    # Binary code is generated byu calling to_risc, then positioning and calling
-    # create_binary on the linker. The linker may then be used to creat a binary file.
-    # The biary the method name refers to is binary code in memory, or in BinaryCode
-    # objects to be precise.
-    def to_binary(platform)
-      linker = to_risc
-      linker.position_all
-      linker.create_binary(platform)
-      linker
+    # ruby_to_target creates Target instructions (but does not link)
+    #
+    # After creating vool, we call to_target
+    # Return a Linker
+    def ruby_to_target(ruby)
+      ruby_to_vool(ruby)
+      to_target()
     end
 
-    # ruby_to_risc creates Risc instructions (as the name implies), but also
-    # translates those to the platform given
+    # ruby_to_risc creates Risc instructions
     #
     # After creating vool, we call to_risc
+    # Return a RiscCollection
     def ruby_to_risc(ruby)
       ruby_to_vool(ruby)
       to_risc()
     end
 
-    # Process previously stored vool source. First to mom, then to risc.
-    def to_risc()
-      mom = to_mom
-      mom.to_risc()
-    end
-
-    # ruby_to_mom does exactly that, it transform the incoming ruby source (string)
-    # to mom
-    # The vool is stored using ruby_to_vool, and if there was previous source,
-    # this will also be momed
+    # Transform the incoming ruby source (string)  to mom
+    #
+    # The vool is stored using ruby_to_vool,the to_mom is called
+    # Return Mom Statement
     def ruby_to_mom(ruby)
       ruby_to_vool(ruby)
       to_mom
     end
 
+    # Process previously stored vool source to binary.
+    # Binary code is generated by calling to_risc, then positioning and calling
+    # create_binary on the linker. The linker may then be used to creat a binary file.
+    # The biary the method name refers to is binary code in memory, or in BinaryCode
+    # objects to be precise.
+    def to_binary(platform)
+      linker = to_target(platform)
+      linker.position_all
+      linker.create_binary
+      linker
+    end
+
+    # transform stored vool to target code
+    # return a linker
+    def to_target(platform)
+      collection = to_risc
+      collection.translate(platform)
+    end
+
+    # Process previously stored vool source to risc.
+    # return a Risc::RiscCollection , a collection of MethodCompilers
+    def to_risc()
+      mom = to_mom
+      mom.to_risc()
+    end
+
     # return mom for the previously stored vool source.
     def to_mom
       @vool.to_mom(nil)
diff --git a/test/mom/instruction/test_slot_load.rb b/test/mom/instruction/test_slot_load.rb
index 83de985c..600daabd 100644
--- a/test/mom/instruction/test_slot_load.rb
+++ b/test/mom/instruction/test_slot_load.rb
@@ -4,17 +4,17 @@ module Mom
   class TestSlotLoadBasics < MiniTest::Test
 
     def test_ins_ok
-      assert SlotLoad.new( [:message, :caller] , [:receiver,:type] )
+      assert SlotLoad.new("test", [:message, :caller] , [:receiver,:type] )
     end
     def test_ins_fail1
-      assert_raises {SlotLoad.new( [:message, :caller] , nil )}
+      assert_raises {SlotLoad.new( "test",[:message, :caller] , nil )}
     end
     def test_fail_on_right
-      @load = SlotLoad.new( [:message, :caller] , [:receiver,:type] )
+      @load = SlotLoad.new( "test",[:message, :caller] , [:receiver,:type] )
       assert_raises {@load.to_risc(Risc::FakeCompiler.new)}
     end
     def test_fail_on_left_long
-      @load = SlotLoad.new( [:message, :caller , :type] , [:receiver,:type] )
+      @load = SlotLoad.new("test", [:message, :caller , :type] , [:receiver,:type] )
       assert_raises {@load.to_risc(Risc::FakeCompiler.new)}
     end
   end
diff --git a/test/mom/instruction/test_slot_load1.rb b/test/mom/instruction/test_slot_load1.rb
index 66e9fbb0..a3ce9139 100644
--- a/test/mom/instruction/test_slot_load1.rb
+++ b/test/mom/instruction/test_slot_load1.rb
@@ -5,7 +5,7 @@ module Mom
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
-      load = SlotLoad.new( [:message, :caller] , [:message,:type] )
+      load = SlotLoad.new("test", [:message, :caller] , [:message,:type] )
       @compiler = Risc::FakeCompiler.new
       load.to_risc(@compiler)
       @instructions = @compiler.instructions
diff --git a/test/mom/instruction/test_slot_load2.rb b/test/mom/instruction/test_slot_load2.rb
index 3f8f3dd3..4a4aa637 100644
--- a/test/mom/instruction/test_slot_load2.rb
+++ b/test/mom/instruction/test_slot_load2.rb
@@ -6,7 +6,7 @@ module Mom
     def setup
       Parfait.boot!(Parfait.default_test_options)
       @compiler = Risc::FakeCompiler.new
-      load = SlotLoad.new( [:message, :caller, :type] , [:message, :caller , :type] )
+      load = SlotLoad.new( "test",[:message, :caller, :type] , [:message, :caller , :type] )
       load.to_risc(@compiler)
       @instructions = @compiler.instructions
     end
diff --git a/test/mom/test_class_statement.rb b/test/mom/test_class_statement.rb
index ed378d36..55e24d3f 100644
--- a/test/mom/test_class_statement.rb
+++ b/test/mom/test_class_statement.rb
@@ -2,7 +2,7 @@
 require_relative "helper"
 
 module Vool
-  class TestClassStatement < MiniTest::Test
+  class TestClassStatementMom < MiniTest::Test
     include MomCompile
 
     def setup
diff --git a/test/mom/test_mom_compiler.rb b/test/mom/test_mom_compiler.rb
deleted file mode 100644
index 5ba6c0c3..00000000
--- a/test/mom/test_mom_compiler.rb
+++ /dev/null
@@ -1,40 +0,0 @@
-require_relative "helper"
-
-module Mom
-  class TestMomCompiler < MiniTest::Test
-    include MomCompile
-
-    def setup
-      Parfait.boot!(Parfait.default_test_options)
-      @comp = compile_mom( "class Test ; def main(); return 'Hi'; end; end;")
-    end
-
-    def test_class
-      assert_equal MomCompiler , @comp.class
-    end
-    def test_compilers
-      assert_equal 23 , @comp.compilers.length
-    end
-    def test_boot_compilers
-      assert_equal 22 , @comp.boot_compilers.length
-    end
-    def test_compilers_bare
-      assert_equal 22 , MomCompiler.new.compilers.length
-    end
-    def test_returns_constants
-      assert_equal Array , @comp.constants.class
-    end
-    def test_has_constant
-      assert_equal  "Hi" , @comp.constants[1].to_string
-    end
-    def test_has_translate
-      assert @comp.translate(:interpreter)
-    end
-    def test_append_class
-      assert_equal MomCompiler,  (@comp.append @comp).class
-    end
-    def test_append_length
-      assert_equal 2 ,  @comp.append(@comp).method_compilers.length
-    end
-  end
-end
diff --git a/test/parfait/test_space2.rb b/test/parfait/test_space2.rb
index 0b08895d..4b1b519c 100644
--- a/test/parfait/test_space2.rb
+++ b/test/parfait/test_space2.rb
@@ -4,11 +4,11 @@ module Parfait
   class TestMethods < ParfaitTest
     def setup
       super
-      Risc::Builtin.boot_functions
+      Mom.boot!
     end
     def test_integer
       int = Parfait.object_space.get_class_by_name :Integer
-      assert_equal 14, int.instance_type.method_names.get_length
+      assert_equal 13, int.instance_type.method_names.get_length
     end
     def test_methods_booted
       word = @space.get_type_by_class_name(:Word)
diff --git a/test/risc/interpreter/builtin/test_int_cmp.rb b/test/risc/interpreter/builtin/test_int_cmp.rb
index af8b66da..e9024ee6 100644
--- a/test/risc/interpreter/builtin/test_int_cmp.rb
+++ b/test/risc/interpreter/builtin/test_int_cmp.rb
@@ -1,9 +1,9 @@
-require_relative "helper"
+require_relative "../helper"
 
 # TODO move these to interpreter dir
-module Mom
+module Risc
   module Builtin
-    class IntCmp < BuiltinTest
+    class IntCmp < Minitest::Test
       include Ticker
       def setup
       end
diff --git a/test/risc/interpreter/builtin/test_int_math.rb b/test/risc/interpreter/builtin/test_int_math.rb
index c22cc652..514e947e 100644
--- a/test/risc/interpreter/builtin/test_int_math.rb
+++ b/test/risc/interpreter/builtin/test_int_math.rb
@@ -1,8 +1,8 @@
-require_relative "helper"
+require_relative "../helper"
 
-module Mom
+module Risc
   module Builtin
-    class IntMath < BuiltinTest
+    class IntMath < Minitest::Test
       include Ticker
       def setup
       end
diff --git a/test/risc/position/test_code_listener1.rb b/test/risc/position/test_code_listener1.rb
index dccfdb5f..bb528e3d 100644
--- a/test/risc/position/test_code_listener1.rb
+++ b/test/risc/position/test_code_listener1.rb
@@ -5,7 +5,7 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:interpreter)
+      @linker = Mom::MomCollection.new.to_risc.translate(:interpreter)
       @binary = Parfait::BinaryCode.new(1)
       @method = Parfait.object_space.types.values.first.methods
       @label = Risc.label("hi","ho")
diff --git a/test/risc/position/test_position3.rb b/test/risc/position/test_position3.rb
index 5a4060fe..b41a4a55 100644
--- a/test/risc/position/test_position3.rb
+++ b/test/risc/position/test_position3.rb
@@ -4,8 +4,9 @@ module Risc
   class TestMachinePositions < MiniTest::Test
     def setup_for(platform)
       Parfait.boot!(Parfait.default_test_options)
+      Mom.boot!
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(platform)
+      @linker = Mom::MomCollection.new.to_risc.translate(platform)
       @linker.position_all
     end
     def test_cpu_init
diff --git a/test/risc/test_builder.rb b/test/risc/test_builder.rb
index e0fcf969..6bf06c2a 100644
--- a/test/risc/test_builder.rb
+++ b/test/risc/test_builder.rb
@@ -5,9 +5,10 @@ module Risc
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
+      Mom.boot!
       Risc.boot!
       init = Parfait.object_space.get_init
-      @builder = Risc::MethodCompiler.new( init ).builder(init)
+      @builder = Risc::MethodCompiler.new( init ,Mom::Label.new( "source_name", "return_label")).builder(init)
       @label = Risc.label("source","name")
       @start = @builder.compiler.current
     end
diff --git a/test/risc/test_builder1.rb b/test/risc/test_builder1.rb
index c132fb5c..74ee6633 100644
--- a/test/risc/test_builder1.rb
+++ b/test/risc/test_builder1.rb
@@ -5,9 +5,10 @@ module Risc
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
+      Mom.boot!
       Risc.boot!
       @init = Parfait.object_space.get_init
-      @compiler = Risc::MethodCompiler.new( @init )
+      @compiler = Risc::MethodCompiler.new( @init , Mom::Label.new( "source_name", "return_label"))
       @builder  = @compiler.builder(@init)
     end
     def test_inserts_built
@@ -42,7 +43,7 @@ module Risc
     end
     def test_allocate_len
       int = @builder.allocate_int
-      assert_equal 41 , @builder.compiler.risc_instructions.length
+      assert_equal 28 , @builder.compiler.risc_instructions.length
     end
   end
 end
diff --git a/test/risc/test_builder2.rb b/test/risc/test_builder2.rb
index 8f6feb15..0f61bba2 100644
--- a/test/risc/test_builder2.rb
+++ b/test/risc/test_builder2.rb
@@ -5,9 +5,10 @@ module Risc
 
     def setup
       Parfait.boot!(Parfait.default_test_options)
+      Mom.boot!
       Risc.boot!
       @init = Parfait.object_space.get_init
-      @compiler = Risc::MethodCompiler.new( @init )
+      @compiler = Risc::MethodCompiler.new( @init, Mom::Label.new( "source_name", "return_label") )
       @builder  = @compiler.builder(@init)
     end
     def test_list
diff --git a/test/risc/test_collector.rb b/test/risc/test_collector.rb
index bd45435d..74fe2057 100644
--- a/test/risc/test_collector.rb
+++ b/test/risc/test_collector.rb
@@ -6,12 +6,12 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:arm)
+      @linker = Mom::MomCollection.new.to_risc.translate(:arm)
     end
 
     def test_simple_collect
       objects = Collector.collect_space(@linker)
-      assert_equal 600 ,  objects.length , objects.length.to_s
+      assert_equal 621 ,  objects.length , objects.length.to_s
     end
 
     def test_collect_all_types
@@ -47,15 +47,15 @@ module Risc
 
     def setup
       opt = Parfait.default_test_options
-      opt[:factory] = 4000
+      opt[:factory] = 400
       Parfait.boot!(opt)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:arm)
+      @linker = Mom::MomCollection.new.to_risc.translate(:arm)
     end
 
     def test_simple_collect
       objects = Collector.collect_space(@linker)
-      assert_equal 20329, objects.length , objects.length.to_s
+      assert_equal 2422, objects.length , objects.length.to_s
     end
 
     def test_integer_positions
diff --git a/test/risc/test_interpreter.rb b/test/risc/test_interpreter.rb
index 8e77f8c2..67e9d436 100644
--- a/test/risc/test_interpreter.rb
+++ b/test/risc/test_interpreter.rb
@@ -4,8 +4,9 @@ module Risc
   class TestInterpreterBasics < MiniTest::Test
     def setup
       Parfait.boot!(Parfait.default_test_options)
+      Mom.boot!
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:interpreter)
+      @linker = Mom::MomCollection.new.to_risc.translate(:interpreter)
     end
 
     def test_class
@@ -54,7 +55,7 @@ module Risc
     end
     def test_pc1
       @interpreter.tick
-      assert_equal 23672 , @interpreter.pc
+      assert_equal 22856 , @interpreter.pc
     end
     def test_tick2
       @interpreter.tick
@@ -68,7 +69,7 @@ module Risc
     def test_pc2
       @interpreter.tick
       @interpreter.tick
-      assert_equal 23676 , @interpreter.pc
+      assert_equal 22860 , @interpreter.pc
     end
     def test_tick_14_jump
       14.times {@interpreter.tick}
diff --git a/test/risc/test_linker.rb b/test/risc/test_linker.rb
index fb506201..aaf02a84 100644
--- a/test/risc/test_linker.rb
+++ b/test/risc/test_linker.rb
@@ -6,7 +6,7 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:arm)
+      @linker = Mom::MomCollection.new.to_risc.translate(:arm)
     end
     def test_objects
       objects = @linker.object_positions
@@ -25,7 +25,7 @@ module Risc
       assert_equal 0 ,  Position.get(@linker.cpu_init).at
     end
     def test_cpu_at
-      assert_equal "0x569c" ,  Position.get(@linker.cpu_init.first).to_s
+      assert_equal "0x562c" ,  Position.get(@linker.cpu_init.first).to_s
     end
     def test_cpu_label
       assert_equal Position ,  Position.get(@linker.cpu_init.first).class
diff --git a/test/risc/test_linker1.rb b/test/risc/test_linker1.rb
index 8d846477..14aeff34 100644
--- a/test/risc/test_linker1.rb
+++ b/test/risc/test_linker1.rb
@@ -4,7 +4,7 @@ module Risc
   class TestMachinePos < MiniTest::Test
     def setup
       code = "class Space; def main(arg);a = 1;return a;end;end"
-      @linker = RubyX::RubyXCompiler.new(RubyX.default_test_options).ruby_to_risc(code,:arm)
+      @linker = RubyX::RubyXCompiler.new(RubyX.default_test_options).ruby_to_binary(code, :arm)
       @linker.position_all
     end
     def test_positions_set
diff --git a/test/risc/test_text_writer.rb b/test/risc/test_text_writer.rb
index fe6c931a..42e3b5d6 100644
--- a/test/risc/test_text_writer.rb
+++ b/test/risc/test_text_writer.rb
@@ -6,7 +6,7 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:arm)
+      @linker = Mom::MomCollection.new.to_risc.translate(:arm)
     end
     def test_init
       @text_writer = TextWriter.new(@linker)
@@ -21,7 +21,7 @@ module Risc
     def setup
       Parfait.boot!(Parfait.default_test_options)
       Risc.boot!
-      @linker = Mom::MomCompiler.new.translate(:arm)
+      @linker = Mom::MomCollection.new.to_risc.translate(:arm)
       @linker.position_all
       @linker.create_binary
       @text_writer = TextWriter.new(@linker)