implementing NOP command.

src/main/java/de/mcs/tools/sps/holtec/HoltecEmulator.java

@@ -7,6 +7,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import de.mcs.tools.sps.AbstractEmulator;
+import de.mcs.tools.sps.EmulatorOutput;
 import de.mcs.tools.sps.SPSCommand;
 import de.mcs.tools.sps.SPSCommandData;
 import de.mcs.tools.sps.SPSCommandDataImpl;
@@ -20,6 +21,7 @@ import de.mcs.tools.sps.SPSEmulator;
 public class HoltecEmulator extends AbstractEmulator implements SPSEmulator {
   private List<SPSCommand> commands = new ArrayList<>();
   {
+    commands.add(SPS_NOP);
     commands.add(SPS_PORT);
     commands.add(SPS_WAIT);
     commands.add(SPS_JUMP_DOWN);
@@ -36,6 +38,13 @@ public class HoltecEmulator extends AbstractEmulator implements SPSEmulator {
     commands.add(SPS_RETURN);
   }
 
+  private static SPSCommand SPS_NOP = new SPSCommandImpl().setName("no operation").setMnemonic("NOP")
+      .setCommandByte((byte) 0x00);
+  static {
+    SPS_NOP.getCommandDatas().add(new SPSCommandDataImpl().setName("nop").setMnemonic("NOP")
+        .setCommandByte((byte) (SPS_NOP.getCommandByte())).setCommand(SPS_NOP));
+  }
+
   private static SPSCommand SPS_PORT = new SPSCommandImpl().setName("Port Output").setMnemonic("PORT")
       .setCommandByte((byte) 0x10);
 
@@ -290,4 +299,18 @@ public class HoltecEmulator extends AbstractEmulator implements SPSEmulator {
     super.reset();
     System.out.println("holtec emulator resettet");
   }
+
+  @Override
+  protected void callNextCommand() {
+    byte command = programMemory[address];
+    SPSCommandData commandData = getCommandData(command);
+    runCommand(commandData);
+    address++;
+  }
+
+  @Override
+  protected EmulatorOutput getEmulatorOutput() {
+    return new EmulatorOutput() {
+    };
+  }
 }