diff --git a/lib/parfait/binary_code.rb b/lib/parfait/binary_code.rb
index f6adfc20..6779be4c 100644
--- a/lib/parfait/binary_code.rb
+++ b/lib/parfait/binary_code.rb
@@ -17,7 +17,8 @@ module Parfait
     end
     def extend_to(total_size)
       if total_size > self.data_length
-        @next = BinaryCode.new(total_size - data_length)
+        @next = BinaryCode.new(1) unless @next
+        @next.extend_to(total_size - data_length)
       end
     end
     def to_s
@@ -40,7 +41,8 @@ module Parfait
     def set_word(index , word)
       raise "invalid index #{index}" if index < 1
       if index > data_length + 1
-        raise "invalid index #{index}" unless @next
+        #raise "invalid index #{index}" unless @next
+        extend_to( index )
         @next.set_word( index - data_length , word)
       end
       set_internal_word(index + 2 , word)
diff --git a/lib/risc/binary_writer.rb b/lib/risc/binary_writer.rb
index 335e65e8..d1eb9ab3 100644
--- a/lib/risc/binary_writer.rb
+++ b/lib/risc/binary_writer.rb
@@ -15,12 +15,15 @@ module Risc
     # LinkException may be thrown, possibly several times
     # So repeat until it works
     def assemble( instruction )
-      ok = false
-      until(ok)
+      not_ok = 1
+      while(not_ok)
         begin
+          #puts "Not ok #{not_ok}"
+          #FIXME really need to reposition here, so jumps go right
           assemble_all(instruction)
-          ok = true
+          not_ok = false
         rescue LinkException
+          not_ok += 1
         end
       end
     end
diff --git a/test/parfait/test_binary_code.rb b/test/parfait/test_binary_code.rb
index e343232f..fbb162df 100644
--- a/test/parfait/test_binary_code.rb
+++ b/test/parfait/test_binary_code.rb
@@ -69,6 +69,17 @@ module Parfait
       assert @code.next
       assert_nil @code.next.next
     end
+    def test_auto_extend #extend by seting word
+      assert_nil @code.next
+      @code.set_word(20 , 1)
+      assert @code.next
+    end
+    def test_extend_extended
+      @code.extend_to(20)
+      @code.extend_to(30)
+      assert @code.next.next
+      assert_nil @code.next.next.next
+    end
     def test_each
       len = 0
       @code.each_word{ len += 1}