diff --git a/src/main/java/com/vectron/fcl/FclStack.java b/src/main/java/com/vectron/fcl/FclStack.java
index 5740da8..878192e 100644
--- a/src/main/java/com/vectron/fcl/FclStack.java
+++ b/src/main/java/com/vectron/fcl/FclStack.java
@@ -2,9 +2,7 @@ package com.vectron.fcl;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
-// import com.vectron.forthcalc.domain.ports.FileStore;
 import com.vectron.fcl.types.Obj;
-import com.vectron.fcl.FclTypeAdapter;
 
 import java.io.BufferedReader;
 import java.io.FileInputStream;
@@ -77,8 +75,6 @@ public class FclStack {
         Collections.reverse(stack);
     }
 
-// TODO
-/*
     public void load(FileStore fileStore, String id) {
         FileInputStream stream = null;
         try {
@@ -107,5 +103,4 @@ public class FclStack {
     private String fileName(String id) {
         return String.format("stack%s.json", id);
     }
-*/
 }
diff --git a/src/main/java/com/vectron/fcl/FileStore.java b/src/main/java/com/vectron/fcl/FileStore.java
new file mode 100644
index 0000000..97458f8
--- /dev/null
+++ b/src/main/java/com/vectron/fcl/FileStore.java
@@ -0,0 +1,23 @@
+package com.vectron.fcl;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.util.List;
+
+public interface FileStore {
+    void save(byte[] raw, String fileName);
+
+    List<String> list();
+
+    List<String> list(Predicate<String> p);
+
+    String read(String fileName);
+
+    FileInputStream open(String fileName) throws FileNotFoundException;
+
+    boolean delete(String fileName);
+
+    interface Predicate<T> {
+        boolean isTrue(T v);
+    }
+}
diff --git a/src/test/java/com/vectron/fcl/FclTest.java b/src/test/java/com/vectron/fcl/FclTest.java
index 1752103..dde47b5 100644
--- a/src/test/java/com/vectron/fcl/FclTest.java
+++ b/src/test/java/com/vectron/fcl/FclTest.java
@@ -1,8 +1,5 @@
 package com.vectron.fcl;
 
-import com.vectron.fcl.Fcl;
-import com.vectron.fcl.FclStack;
-import com.vectron.fcl.RamTranscript;
 import com.vectron.fcl.exceptions.Aborted;
 import com.vectron.fcl.exceptions.NotUnderstood;
 import com.vectron.fcl.exceptions.TypeMismatched;