diff --git a/.idea/misc.xml b/.idea/misc.xml
index 18d93cc..e1a5887 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -51,7 +51,7 @@
     <ConfirmationsSetting value="0" id="Add" />
     <ConfirmationsSetting value="0" id="Remove" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/JohnnyScript.iml b/JohnnyScript.iml
index 57d8cbd..5eb0105 100644
--- a/JohnnyScript.iml
+++ b/JohnnyScript.iml
@@ -7,7 +7,7 @@
       <sourceFolder url="file://$MODULE_DIR$/test" isTestSource="true" />
       <sourceFolder url="file://$MODULE_DIR$/res" type="java-resource" />
     </content>
-    <orderEntry type="inheritedJdk" />
+    <orderEntry type="jdk" jdkName="1.8" jdkType="JavaSDK" />
     <orderEntry type="sourceFolder" forTests="false" />
     <orderEntry type="module-library" scope="TEST">
       <library name="JUnit4">
diff --git a/src/JohnnyScript.java b/src/JohnnyScript.java
index fa13f31..9bdaee2 100644
--- a/src/JohnnyScript.java
+++ b/src/JohnnyScript.java
@@ -1,3 +1,5 @@
+import com.sun.org.apache.bcel.internal.classfile.Code;
+
 import java.io.IOException;
 import java.nio.file.FileSystems;
 import java.nio.file.Path;
@@ -24,24 +26,49 @@ public static void main(String[] args) throws IOException {
     private static List<String> compileCode(List<String> lines) {
         List<String> compiled = new ArrayList<>();
 
-        for (String line: lines) {
-            String compiledLine = compile(line);
-            if (!compiledLine.equals("")) {
-                compiled.add(compiledLine);
-            }
+        for (int i = 0; i <= 999; i++) {
+            if (i < lines.size()) {
+                try {
+                    String compiledLine = compile(lines.get(i));
+                    if (compiledLine != null) {
+                        compiled.add(compiledLine);
+                    } else {
+                        lines.remove(i); // Remove comment line from source
+                        i--;            // Reduce index to continue at next line without skipping
+                    }
+                } catch (InvalidScriptException e) {
+                    throw new CompilerHaltException("Invalid code at line " + i, e);
+                }
+            } else compiled.add("000");
         }
 
         return compiled;
     }
 
-    private static String compile(String line) {
+    private static String compile(String line) throws InvalidScriptException {
         if (line.contains(LINE_COMMENT_DELIMITER)) {
             int commentStart = line.indexOf(LINE_COMMENT_DELIMITER);
             String nonComment = line.substring(0, commentStart);
-            return nonComment.trim();
+            if (!nonComment.equals(""))
+                return encode(nonComment);
+            else return null;
         }
         else
-            return line.trim();
+            return encode(line);
+    }
+
+    private static String encode(String line) throws InvalidScriptException {
+        String[] parts = line.trim().split(" ");
+        if (parts.length > 2) throw new InvalidScriptException("InvalidJohnnyScript (too many parts): " + line);
+        if (parts.length == 1) {
+            return String.format("%03d", Integer.parseInt(parts[0]));
+        }
+        // else there are two parts
+        String code = parts[0].toUpperCase();
+        String lo = String.format("%03d", Integer.parseInt(parts[1]));
+        String hi = Codes.valueOf(code).getCode();
+        return hi + lo;
+
     }
 
     /**
@@ -94,4 +121,32 @@ private static void checkInputFile(Path path) {
         }
     }
 
+    private enum Codes {
+        TAKE(1), ADD(2), SUB(3), SAVE(4), JMP(5), TST(6), INC(7), DEC(8), NULL(9), HLT(10);
+
+        int codeOrdinal = 0;
+
+        Codes(int ord) {
+            this.codeOrdinal = ord;
+        }
+
+        public String getCode() {
+            return String.valueOf(codeOrdinal);
+        }
+    }
+
+}
+
+class InvalidScriptException extends Exception {
+
+    InvalidScriptException(String message) {
+        super(message);
+    }
+}
+
+class CompilerHaltException extends RuntimeException {
+
+    CompilerHaltException(String message, Throwable cause) {
+        super(message, cause);
+    }
 }
diff --git a/test/JohnnyScriptTest.java b/test/JohnnyScriptTest.java
index 3ef0b2d..e7b590a 100644
--- a/test/JohnnyScriptTest.java
+++ b/test/JohnnyScriptTest.java
@@ -81,10 +81,10 @@ public void commentLine() throws Exception {
         List outLines = Files.readAllLines(outputPath);
 
         testCode = new ArrayList<>();
-        testCode.add("add 0");
-        testCode.add("add 0");
+        testCode.add("2000");
+        testCode.add("2000");
 
-        assertEquals(testCode.size(), outLines.size());
+        assertEquals(1000, outLines.size());
         for (int i = 0; i < testCode.size(); i++) {
             assertEquals("Line " + i, testCode.get(i),outLines.get(i));
         }
@@ -106,15 +106,17 @@ public void commentInline() throws Exception {
         List outLines = Files.readAllLines(outputPath);
 
         testCode = new ArrayList<>();
-        testCode.add("add 0");
-        testCode.add("add 1");
-        testCode.add("add 0");
+        testCode.add("2000");
+        testCode.add("2001");
+        testCode.add("2000");
 
-        assertEquals(testCode.size(), outLines.size());
+        assertEquals(1000, outLines.size());
         for (int i = 0; i < testCode.size(); i++) {
             assertEquals("Line " + i, testCode.get(i),outLines.get(i));
         }
 
     }
 
+    //TODO Tests for every code
+
 }
\ No newline at end of file