diff --git a/2019/Scala/intcode/State.scala b/2019/Scala/intcode/State.scala
index 03a1dfb..28dcc2e 100644
--- a/2019/Scala/intcode/State.scala
+++ b/2019/Scala/intcode/State.scala
@@ -1,6 +1,6 @@
 package intcode
 
 sealed trait State
-case object Ready extends State
-case object Input extends State
-case object Finished extends State
+case object Ready extends State     // machine ready/working
+case object Input extends State     // machine waiting for input (empty inputStream)
+case object Finished extends State  // machine reached instruction 99