diff --git a/applepy.py b/applepy.py
index 4cab99c..521214a 100644
--- a/applepy.py
+++ b/applepy.py
@@ -773,6 +773,21 @@ class CPU:
                 pygame.display.flip()
                 update_cycle = 0
     
+    def test_run(self, start, end):
+        self.program_counter = start
+        while True:
+            if self.program_counter == end:
+                break
+            op = self.read_pc_byte()
+            func = self.ops[op]
+            if func is None:
+                print "UNKNOWN OP"
+                print hex(self.program_counter - 1)
+                print hex(op)
+                break
+            else:
+                self.ops[op]()
+    
     ####
     
     def get_pc(self, inc=1):