diff --git a/test/interpreter/helper.rb b/test/interpreter/helper.rb
index e49e784a..4bb6c98e 100644
--- a/test/interpreter/helper.rb
+++ b/test/interpreter/helper.rb
@@ -10,4 +10,26 @@ module Ticker
     end
     return last
   end
+
+  def show_ticks
+    classes = []
+    error = nil
+    tick = 1
+    begin
+      while true and (classes.length < 100)
+        cl = ticks(1).class
+        tick += 1
+        classes << cl
+        break if cl == NilClass
+      end
+    rescue => e
+      puts "Error at tick #{tick}"
+      puts e
+    end
+    classes = classes.collect {|c| '"' + c.name.sub("Register::","")  + '",' }
+    classes.each_slice(5).each do |line|
+      puts "     " + line.join
+    end
+    exit(1)
+  end
 end
diff --git a/test/interpreter/test_add.rb b/test/interpreter/test_add.rb
index a024e502..96428b05 100644
--- a/test/interpreter/test_add.rb
+++ b/test/interpreter/test_add.rb
@@ -65,14 +65,10 @@ class AddTest < MiniTest::Test
   end
 
   def test_chain
-    ["Branch" , "LoadConstant" , "GetSlot" , "SetSlot" , "RegisterTransfer" ,
-#     "GetSlot" , "FunctionCall" , "SaveReturn" , "LoadConstant"  , "LoadConstant" ,
-#     "OperatorInstruction" ,  "RegisterTransfer" , "GetSlot" , "LoadConstant" , "SetSlot" ,
-#     "LoadConstant" ,  "SetSlot" ,   "GetSlot" , "SetSlot", "RegisterTransfer" , "GetSlot" , "FunctionCall" ,
-#     "SaveReturn" ,  "GetSlot", "OperatorInstruction" , "RegisterTransfer" , "GetSlot" , "GetSlot" ,
-     "GetSlot" , "FunctionCall" ,"SaveReturn" , "LoadConstant", "LoadConstant"].each_with_index do |name , index|
+    ["Branch","LoadConstant","GetSlot","SetSlot","RegisterTransfer",
+     "GetSlot","FunctionCall","SaveReturn","LoadConstant","LoadConstant",
+     "OperatorInstruction","RegisterTransfer","GetSlot"].each_with_index do |name , index|
       got = ticks(1)
-      puts got
       assert got.class.name.index(name) , "Wrong class for #{index+1}, expect #{name} , got #{got}"
     end
   end
diff --git a/test/interpreter/test_puti.rb b/test/interpreter/test_puti.rb
index 4d623ee5..7e0eb619 100644
--- a/test/interpreter/test_puti.rb
+++ b/test/interpreter/test_puti.rb
@@ -59,24 +59,23 @@ HERE
     Virtual.machine.run_before "Register::CallImplementation"
     @interpreter = Interpreter::Interpreter.new
     @interpreter.start Virtual.machine.init
-#    done = ticks(34)
-  ["Branch" ,     "LoadConstant" ,    "GetSlot" ,     "SetSlot" ,        "RegisterTransfer" ,
-   "GetSlot" ,    "FunctionCall" ,    "SaveReturn",   "LoadConstant" ,   "GetSlot" ,
-   "SetSlot" ,    "LoadConstant" ,    "SetSlot" ,     "RegisterTransfer" , "GetSlot" ,
-   "FunctionCall" ,"SaveReturn" ,     "GetSlot" ,     "LoadConstant" ,   "SetSlot" ,
-   "GetSlot",     "SetSlot",          "LoadConstant" ,"SetSlot" ,        "GetSlot" ,
-   "SetSlot",     "RegisterTransfer", "GetSlot" ,     "FunctionCall" ,   "SaveReturn",
-   "GetSlot",     "LoadConstant",     "OperatorInstruction",   "SetSlot", "GetSlot",
-   "OperatorInstruction","SetSlot",   "GetSlot",      "LoadConstant",    "OperatorInstruction",
-   "Branch",     "GetSlot",           "SetSlot",      "LoadConstant",    "SetSlot",
-   "GetSlot",     "SetSlot",          "RegisterTransfer", "GetSlot",     "FunctionCall",
-   "SaveReturn",  "GetSlot",          "LoadConstant",  "OperatorInstruction","Branch",
-   "LoadConstant", "GetSlot",         "LoadConstant",  "OperatorInstruction","Branch",
-   "LoadConstant", "GetSlot",         "LoadConstant",  "OperatorInstruction","Branch",
-   "LoadConstant",  "GetSlot",        "LoadConstant",  "OperatorInstruction","Branch",
-   "LoadConstant"].each_with_index do |name , index|
+    ["Branch","LoadConstant","GetSlot","SetSlot","RegisterTransfer",
+     "GetSlot","FunctionCall","SaveReturn","LoadConstant","GetSlot",
+     "SetSlot","LoadConstant","SetSlot","RegisterTransfer","GetSlot",
+     "FunctionCall","SaveReturn","GetSlot","LoadConstant","SetSlot",
+     "GetSlot","SetSlot","LoadConstant","SetSlot","GetSlot",
+     "SetSlot","RegisterTransfer","GetSlot","FunctionCall","SaveReturn",
+     "GetSlot","LoadConstant","OperatorInstruction","SetSlot","GetSlot",
+     "OperatorInstruction","SetSlot","GetSlot","LoadConstant","OperatorInstruction",
+     "IsZeroBranch","GetSlot","SetSlot","LoadConstant","SetSlot",
+     "GetSlot","SetSlot","RegisterTransfer","GetSlot","FunctionCall",
+     "SaveReturn","GetSlot","LoadConstant","OperatorInstruction","IsZeroBranch",
+     "LoadConstant","GetSlot","LoadConstant","OperatorInstruction","IsZeroBranch",
+     "LoadConstant","GetSlot","LoadConstant","OperatorInstruction","IsZeroBranch",
+     "LoadConstant","GetSlot","LoadConstant","OperatorInstruction","IsZeroBranch",
+     "LoadConstant","GetSlot","LoadConstant","OperatorInstruction","IsZeroBranch",
+     "LoadConstant","NilClass"].each_with_index do |name , index|
     got = ticks(1)
-    puts got
     assert got.class.name.index(name) , "Wrong class for #{index+1}, expect #{name} , got #{got}"
 end
 
diff --git a/test/interpreter/test_puts.rb b/test/interpreter/test_puts.rb
index 76d746de..115eff8f 100644
--- a/test/interpreter/test_puts.rb
+++ b/test/interpreter/test_puts.rb
@@ -55,13 +55,14 @@ class TestPuts < MiniTest::Test
   end
 
   def test_chain
-    ["Branch" , "LoadConstant" , "GetSlot" , "SetSlot" , "RegisterTransfer" ,
-     "GetSlot" , "FunctionCall" , "SaveReturn" , "LoadConstant"  , "GetSlot" ,
-     "SetSlot" ,  "LoadConstant" , "SetSlot" , "RegisterTransfer" , "GetSlot" ,
-     "FunctionCall" ,  "SaveReturn" ,  "RegisterTransfer" , "Syscall" , "RegisterTransfer" ,
-     "RegisterTransfer" , "SetSlot" , "GetSlot" , "GetSlot" , "RegisterTransfer" ,
-     "GetSlot" , "GetSlot" ,"GetSlot" , "FunctionReturn","RegisterTransfer",
-     "Syscall" , "NilClass"].each_with_index do |name , index|
+    show_ticks
+    ["Branch","LoadConstant","GetSlot","SetSlot","RegisterTransfer",
+   "GetSlot","FunctionCall","SaveReturn","LoadConstant","GetSlot",
+   "SetSlot","LoadConstant","SetSlot","RegisterTransfer","GetSlot",
+   "FunctionCall","SaveReturn","RegisterTransfer","Syscall","RegisterTransfer",
+   "RegisterTransfer","SetSlot","GetSlot","GetSlot","RegisterTransfer",
+   "GetSlot","GetSlot","GetSlot","FunctionReturn","RegisterTransfer",
+   "Syscall","NilClass"].each_with_index do |name , index|
       got = ticks(1)
       #puts "TICK #{index}"
       assert got.class.name.index(name) , "Wrong class for #{index+1}, expect #{name} , got #{got}"