diff --git a/test/register/test_all.rb b/test/register/test_all.rb
index 041b2cb7..3f4f1101 100644
--- a/test/register/test_all.rb
+++ b/test/register/test_all.rb
@@ -1,5 +1,6 @@
 require_relative "interpreter/test_all"
 
+require_relative "test_assembler"
 require_relative "test_collector"
 require_relative "test_compat"
 require_relative "test_instructions"
diff --git a/test/register/test_assembler.rb b/test/register/test_assembler.rb
new file mode 100644
index 00000000..125bd547
--- /dev/null
+++ b/test/register/test_assembler.rb
@@ -0,0 +1,43 @@
+require_relative "../helper"
+
+module Register
+  class TestAssembler < MiniTest::Test
+
+    def setup
+      @machine = Register.machine.boot
+    end
+    def test_no_object
+      @assembler = Assembler.new(@machine , {})
+      assert_nil @machine.translate_arm
+    end
+    def test_space
+      @assembler = Assembler.new(@machine , Collector.collect_space)
+      assert_nil @machine.translate_arm
+    end
+
+    def test_write_fails
+      @assembler = Assembler.new(@machine , {})
+      assert_raises{ @assembler.assemble} #must translate first
+    end
+    def test_assemble_no_objects
+      @assembler = Assembler.new(@machine , {})
+      assert_nil @machine.translate_arm
+      assert @assembler.assemble
+    end
+
+    def test_translate_space
+      @assembler = Assembler.new(@machine , Collector.collect_space)
+      assert_nil @machine.translate_arm
+    end
+    def test_assemble_space
+      @assembler = Assembler.new(@machine , Collector.collect_space)
+      assert_nil @machine.translate_arm
+      assert @assembler.assemble
+    end
+    def test_write_space
+      @assembler = Assembler.new(@machine , Collector.collect_space)
+      assert_nil @machine.translate_arm
+      assert @assembler.write_as_string
+    end
+  end
+end