adds a MIDI component; closes #228

distribution/Assembly.xml

@@ -105,6 +105,13 @@
                 <include>*.dig</include>
             </includes>
         </fileSet>
+        <fileSet>
+            <directory>${basedir}/src/main/dig/misc</directory>
+            <outputDirectory>/examples/misc/</outputDirectory>
+            <includes>
+                <include>*.dig</include>
+            </includes>
+        </fileSet>
         <fileSet>
             <directory>${basedir}/src/main/dig/hdl</directory>
             <outputDirectory>/examples/hdl/</outputDirectory>

distribution/ReleaseNotes.txt

@@ -7,6 +7,7 @@ HEAD, planned as v0.22
 - Now its possible to create circuits using lookup tables.
 - More consistent handling of the initial state in the FSM editor.
 - Added a rectangle to visually group elements.
+- Added a MIDI component.
 - Added Portuguese translation. Special thanks to Theldo Cruz Franqueira who
   provided the translation.
 

src/main/dig/misc/MIDIexample.dig

@@ -0,0 +1,244 @@
+<?xml version="1.0" encoding="utf-8"?>
+<circuit>
+  <version>1</version>
+  <attributes/>
+  <visualElements>
+    <visualElement>
+      <elementName>In</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Label</string>
+          <string>Vol</string>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>7</int>
+        </entry>
+        <entry>
+          <string>InDefault</string>
+          <value v="127" z="false"/>
+        </entry>
+      </elementAttributes>
+      <pos x="100" y="200"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Clock</elementName>
+      <elementAttributes>
+        <entry>
+          <string>runRealTime</string>
+          <boolean>true</boolean>
+        </entry>
+        <entry>
+          <string>Label</string>
+          <string>C</string>
+        </entry>
+        <entry>
+          <string>Frequency</string>
+          <int>15</int>
+        </entry>
+      </elementAttributes>
+      <pos x="100" y="260"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Counter</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Bits</string>
+          <int>6</int>
+        </entry>
+      </elementAttributes>
+      <pos x="280" y="120"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Ground</elementName>
+      <elementAttributes/>
+      <pos x="260" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Add</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Bits</string>
+          <int>7</int>
+        </entry>
+      </elementAttributes>
+      <pos x="480" y="120"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Ground</elementName>
+      <elementAttributes/>
+      <pos x="460" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Const</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Value</string>
+          <long>30</long>
+        </entry>
+        <entry>
+          <string>Bits</string>
+          <int>7</int>
+        </entry>
+        <entry>
+          <string>intFormat</string>
+          <intFormat>dec</intFormat>
+        </entry>
+      </elementAttributes>
+      <pos x="460" y="140"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Splitter</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Input Splitting</string>
+          <string>6,1</string>
+        </entry>
+        <entry>
+          <string>Output Splitting</string>
+          <string>7</string>
+        </entry>
+      </elementAttributes>
+      <pos x="400" y="120"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Const</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Value</string>
+          <long>0</long>
+        </entry>
+      </elementAttributes>
+      <pos x="380" y="140"/>
+    </visualElement>
+    <visualElement>
+      <elementName>MIDI</elementName>
+      <elementAttributes/>
+      <pos x="580" y="180"/>
+    </visualElement>
+    <visualElement>
+      <elementName>D_FF</elementName>
+      <elementAttributes/>
+      <pos x="140" y="120"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Const</elementName>
+      <elementAttributes/>
+      <pos x="560" y="240"/>
+    </visualElement>
+  </visualElements>
+  <wires>
+    <wire>
+      <p1 x="260" y="160"/>
+      <p2 x="280" y="160"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="160"/>
+      <p2 x="480" y="160"/>
+    </wire>
+    <wire>
+      <p1 x="560" y="240"/>
+      <p2 x="580" y="240"/>
+    </wire>
+    <wire>
+      <p1 x="100" y="260"/>
+      <p2 x="120" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="260"/>
+      <p2 x="240" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="240" y="260"/>
+      <p2 x="580" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="560" y="180"/>
+      <p2 x="580" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="100"/>
+      <p2 x="220" y="100"/>
+    </wire>
+    <wire>
+      <p1 x="100" y="200"/>
+      <p2 x="580" y="200"/>
+    </wire>
+    <wire>
+      <p1 x="540" y="120"/>
+      <p2 x="560" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="200" y="120"/>
+      <p2 x="280" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="420" y="120"/>
+      <p2 x="480" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="340" y="120"/>
+      <p2 x="400" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="120"/>
+      <p2 x="140" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="140"/>
+      <p2 x="140" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="200" y="140"/>
+      <p2 x="220" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="140"/>
+      <p2 x="480" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="380" y="140"/>
+      <p2 x="400" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="240" y="140"/>
+      <p2 x="280" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="220" y="220"/>
+      <p2 x="580" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="560" y="120"/>
+      <p2 x="560" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="240" y="140"/>
+      <p2 x="240" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="260" y="160"/>
+      <p2 x="260" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="140"/>
+      <p2 x="120" y="260"/>
+    </wire>
+    <wire>
+      <p1 x="120" y="100"/>
+      <p2 x="120" y="120"/>
+    </wire>
+    <wire>
+      <p1 x="220" y="100"/>
+      <p2 x="220" y="140"/>
+    </wire>
+    <wire>
+      <p1 x="220" y="140"/>
+      <p2 x="220" y="220"/>
+    </wire>
+    <wire>
+      <p1 x="460" y="160"/>
+      <p2 x="460" y="180"/>
+    </wire>
+  </wires>
+</circuit>

src/main/java/de/neemann/digital/core/ModelEvent.java

@@ -16,7 +16,7 @@ public enum ModelEvent {
     STARTED,
 
     /**
-     * The model had stopped.
+     * The model has stopped.
      */
     STOPPED,
 

src/main/java/de/neemann/digital/core/element/Keys.java

@@ -735,4 +735,24 @@ public final class Keys {
     public static final Key<Boolean> RECT_RIGHT
             = new Key<>("RectRight", false).setSecondary();
 
+
+    /**
+     * Selects the midi channel
+     */
+    public static final Key.KeyInteger MIDI_CHANNEL =
+            new Key.KeyInteger("midiChannel", 1)
+                    .setMin(1)
+                    .setMax(16);
+
+    /**
+     * Selects the midi channel
+     */
+    public static final Key<String> MIDI_INSTRUMENT =
+            new Key<>("midiInstrument", "");
+
+    /**
+     * Enables Program change
+     */
+    public static final Key<Boolean> MIDI_PROG_CHANGE =
+            new Key<>("midiProgChange", false);
 }

src/main/java/de/neemann/digital/core/io/MIDI.java

@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2019 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.core.io;
+
+import de.neemann.digital.core.*;
+import de.neemann.digital.core.element.*;
+
+import javax.sound.midi.MidiChannel;
+
+import static de.neemann.digital.core.element.PinInfo.input;
+
+/**
+ * The speaker.
+ */
+public class MIDI extends Node implements Element {
+
+    /**
+     * The Speakers description
+     */
+    public static final ElementTypeDescription DESCRIPTION
+            = new ElementTypeDescription(MIDI.class) {
+        public PinDescriptions getInputDescription(ElementAttributes elementAttributes) throws NodeException {
+            if (elementAttributes.get(Keys.MIDI_PROG_CHANGE))
+                return new PinDescriptions(input("N"),
+                        input("V"),
+                        input("OnOff"),
+                        input("PC"),
+                        input("en"),
+                        input("C").setClock()).setLangKey(getPinLangKey());
+            else
+                return new PinDescriptions(input("N"),
+                        input("V"),
+                        input("OnOff"),
+                        input("en"),
+                        input("C").setClock()).setLangKey(getPinLangKey());
+        }
+    }
+            .addAttribute(Keys.ROTATE)
+            .addAttribute(Keys.LABEL)
+            .addAttribute(Keys.MIDI_CHANNEL)
+            .addAttribute(Keys.MIDI_INSTRUMENT)
+            .addAttribute(Keys.MIDI_PROG_CHANGE);
+
+    private final int chanNum;
+    private final String instrument;
+    private final boolean progChangeEnable;
+    private ObservableValue note;
+    private ObservableValue volume;
+    private ObservableValue clock;
+    private ObservableValue onOff;
+    private ObservableValue en;
+    private ObservableValue progChange;
+    private MidiChannel channel;
+    private boolean lastCl = false;
+
+    /**
+     * Creates a new instance
+     *
+     * @param attributes the elements attributes
+     */
+    public MIDI(ElementAttributes attributes) {
+        chanNum = attributes.get(Keys.MIDI_CHANNEL) - 1;
+        instrument = attributes.get(Keys.MIDI_INSTRUMENT);
+        progChangeEnable = attributes.get(Keys.MIDI_PROG_CHANGE);
+    }
+
+    @Override
+    public void setInputs(ObservableValues inputs) throws NodeException {
+        note = inputs.get(0).checkBits(7, this, 0);
+        volume = inputs.get(1).checkBits(7, this, 1);
+        onOff = inputs.get(2).checkBits(1, this, 2);
+        if (progChangeEnable) {
+            progChange = inputs.get(3).checkBits(1, this, 3);
+            en = inputs.get(4).checkBits(1, this, 4);
+            clock = inputs.get(5).checkBits(1, this, 5).addObserverToValue(this);
+        } else {
+            en = inputs.get(3).checkBits(1, this, 3);
+            clock = inputs.get(4).checkBits(1, this, 4).addObserverToValue(this);
+        }
+    }
+
+    @Override
+    public ObservableValues getOutputs() {
+        return ObservableValues.EMPTY_LIST;
+    }
+
+    @Override
+    public void readInputs() throws NodeException {
+        boolean cl = clock.getBool();
+        if (!lastCl && cl && en.getBool()) {
+            int note = (int) this.note.getValue();
+            if (progChange != null && progChange.getBool()) {
+                channel.programChange(note);
+            } else {
+                if (onOff.getBool()) {
+                    int v = (int) volume.getValue();
+                    channel.noteOn(note, v);
+                } else
+                    channel.noteOff(note);
+            }
+        }
+        lastCl = cl;
+    }
+
+    @Override
+    public void writeOutputs() throws NodeException {
+    }
+
+    @Override
+    public void init(Model model) throws NodeException {
+        channel = MIDIHelper.getInstance().getChannel(chanNum, instrument, model);
+    }
+}

src/main/java/de/neemann/digital/core/io/MIDIHelper.java

@@ -0,0 +1,347 @@
+/*
+ * Copyright (c) 2019 Helmut Neemann.
+ * Use of this source code is governed by the GPL v3 license
+ * that can be found in the LICENSE file.
+ */
+package de.neemann.digital.core.io;
+
+import de.neemann.digital.core.Model;
+import de.neemann.digital.core.ModelEvent;
+import de.neemann.digital.core.NodeException;
+import de.neemann.digital.lang.Lang;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.sound.midi.*;
+import java.util.ArrayList;
+import java.util.TreeMap;
+
+/**
+ * Helper for MIDI functions
+ */
+public final class MIDIHelper {
+    private static final Logger LOGGER = LoggerFactory.getLogger(MIDIHelper.class);
+    private static MIDIHelper ourInstance = new MIDIHelper();
+
+    /**
+     * @return the MIDIHelper
+     */
+    public static MIDIHelper getInstance() {
+        return ourInstance;
+    }
+
+    private SynthesizerInterface synthesizer;
+    private boolean isOpen;
+    private TreeMap<String, Instrument> instrumentMap;
+
+    private MIDIHelper() {
+    }
+
+    private SynthesizerInterface getSynthesizer() throws NodeException {
+        if (synthesizer == null) {
+            try {
+                final Synthesizer synth = MidiSystem.getSynthesizer();
+                if (synth == null)
+                    throw new NodeException(Lang.get("err_midiSystemNotAvailable"));
+                synthesizer = new RealSynthesizer(synth);
+            } catch (MidiUnavailableException e) {
+                throw new NodeException(Lang.get("err_midiSystemNotAvailable"), e);
+            }
+        }
+        return synthesizer;
+    }
+
+    /**
+     * Opens the synthesizer
+     *
+     * @param model the mode used. If the model is closed also the synthesizer is closed
+     * @throws NodeException NodeException
+     */
+    private void ensureOpen(Model model) throws NodeException {
+        if (!isOpen) {
+            try {
+                getSynthesizer().open();
+            } catch (MidiUnavailableException e) {
+                if (System.getProperty("testdata") == null) {
+                    throw new NodeException(Lang.get("err_midiSystemNotAvailable"), e);
+                } else {
+                    LOGGER.info("Use fake MIDI interface!");
+                    synthesizer = new SynthesizerMock();
+                }
+            }
+
+            isOpen = true;
+
+            model.addObserver(event -> {
+                if (event.equals(ModelEvent.STOPPED))
+                    close();
+            }, ModelEvent.STOPPED);
+        }
+    }
+
+    private void close() {
+        if (isOpen) {
+            synthesizer.close();
+            isOpen = false;
+        }
+    }
+
+    /**
+     * Creates the channel to use
+     *
+     * @param num        the channel number
+     * @param instrument the instrument to use
+     * @param model      the model
+     * @return the channel
+     * @throws NodeException NodeException
+     */
+    public MidiChannel getChannel(int num, String instrument, Model model) throws NodeException {
+        ensureOpen(model);
+
+        Instrument instr = null;
+        if (!instrument.isEmpty())
+            instr = getInstrument(instrument);
+
+        MidiChannel[] channels = getSynthesizer().getChannels();
+        if (num >= channels.length) {
+            close();
+            throw new NodeException(Lang.get("err_midiChannel_N_NotAvailable", num));
+        }
+
+        MidiChannel channel = channels[num];
+        if (channel == null) {
+            close();
+            throw new NodeException(Lang.get("err_midiChannel_N_NotAvailable", num));
+        }
+
+        if (instr != null) {
+            final Patch patch = instr.getPatch();
+            channel.programChange(patch.getBank(), patch.getProgram());
+        }
+
+        return channel;
+    }
+
+    /**
+     * @return the list of available instruments
+     * @throws NodeException NodeException
+     */
+    public String[] getInstruments() throws NodeException {
+        return new ArrayList<>(getInstumentMap().keySet()).toArray(new String[0]);
+    }
+
+    private Instrument getInstrument(String instrument) throws NodeException {
+        Instrument i = getInstumentMap().get(instrument);
+        if (i == null)
+            throw new NodeException(Lang.get("err_midiInstrument_N_NotAvailable", instrument));
+        return i;
+    }
+
+    private TreeMap<String, Instrument> getInstumentMap() throws NodeException {
+        if (instrumentMap == null) {
+            instrumentMap = new TreeMap<>();
+            instrumentMap.put("", null);
+            for (Instrument i : getSynthesizer().getAvailableInstruments()) {
+                instrumentMap.put(i.getName(), i);
+            }
+        }
+        return instrumentMap;
+    }
+
+    private interface SynthesizerInterface {
+        void open() throws MidiUnavailableException;
+
+        void close();
+
+        Instrument[] getAvailableInstruments();
+
+        MidiChannel[] getChannels();
+    }
+
+    private static final class RealSynthesizer implements SynthesizerInterface {
+        private final Synthesizer synthesizer;
+
+        private RealSynthesizer(Synthesizer synthesizer) {
+            this.synthesizer = synthesizer;
+        }
+
+        @Override
+        public void open() throws MidiUnavailableException {
+            synthesizer.open();
+
+            Soundbank soundbank = synthesizer.getDefaultSoundbank();
+            if (soundbank == null)
+                throw new MidiUnavailableException(Lang.get("err_midiInstrumentsNotAvailable"));
+
+            if (!synthesizer.loadAllInstruments(soundbank))
+                throw new MidiUnavailableException(Lang.get("err_midiInstrumentsNotAvailable"));
+        }
+
+        @Override
+        public void close() {
+            synthesizer.close();
+        }
+
+        @Override
+        public Instrument[] getAvailableInstruments() {
+            return synthesizer.getAvailableInstruments();
+        }
+
+        @Override
+        public MidiChannel[] getChannels() {
+            return synthesizer.getChannels();
+        }
+    }
+
+    private static final class SynthesizerMock implements SynthesizerInterface {
+        @Override
+        public void open() {
+        }
+
+        @Override
+        public void close() {
+        }
+
+        @Override
+        public Instrument[] getAvailableInstruments() {
+            return new Instrument[0];
+        }
+
+        @Override
+        public MidiChannel[] getChannels() {
+            final MidiChannel dummy = new MidiChannel() {
+                @Override
+                public void noteOn(int i, int i1) {
+                }
+
+                @Override
+                public void noteOff(int i, int i1) {
+                }
+
+                @Override
+                public void noteOff(int i) {
+                }
+
+                @Override
+                public void setPolyPressure(int i, int i1) {
+                }
+
+                @Override
+                public int getPolyPressure(int i) {
+                    return 0;
+                }
+
+                @Override
+                public void setChannelPressure(int i) {
+
+                }
+
+                @Override
+                public int getChannelPressure() {
+                    return 0;
+                }
+
+                @Override
+                public void controlChange(int i, int i1) {
+
+                }
+
+                @Override
+                public int getController(int i) {
+                    return 0;
+                }
+
+                @Override
+                public void programChange(int i) {
+
+                }
+
+                @Override
+                public void programChange(int i, int i1) {
+
+                }
+
+                @Override
+                public int getProgram() {
+                    return 0;
+                }
+
+                @Override
+                public void setPitchBend(int i) {
+
+                }
+
+                @Override
+                public int getPitchBend() {
+                    return 0;
+                }
+
+                @Override
+                public void resetAllControllers() {
+
+                }
+
+                @Override
+                public void allNotesOff() {
+
+                }
+
+                @Override
+                public void allSoundOff() {
+
+                }
+
+                @Override
+                public boolean localControl(boolean b) {
+                    return false;
+                }
+
+                @Override
+                public void setMono(boolean b) {
+
+                }
+
+                @Override
+                public boolean getMono() {
+                    return false;
+                }
+
+                @Override
+                public void setOmni(boolean b) {
+
+                }
+
+                @Override
+                public boolean getOmni() {
+                    return false;
+                }
+
+                @Override
+                public void setMute(boolean b) {
+
+                }
+
+                @Override
+                public boolean getMute() {
+                    return false;
+                }
+
+                @Override
+                public void setSolo(boolean b) {
+
+                }
+
+                @Override
+                public boolean getSolo() {
+                    return false;
+                }
+            };
+            return new MidiChannel[]{
+                    dummy, dummy, dummy, dummy,
+                    dummy, dummy, dummy, dummy,
+                    dummy, dummy, dummy, dummy,
+                    dummy, dummy, dummy, dummy};
+        }
+    }
+
+}

src/main/java/de/neemann/digital/draw/library/ElementLibrary.java

@@ -140,7 +140,8 @@ public class ElementLibrary implements Iterable<ElementLibrary.ElementContainer>
                                 .add(DummyElement.DATADESCRIPTION)
                                 .add(RotEncoder.DESCRIPTION)
                                 .add(Keyboard.DESCRIPTION)
-                                .add(Terminal.DESCRIPTION)))
+                                .add(Terminal.DESCRIPTION)
+                                .add(MIDI.DESCRIPTION)))
                 .add(new LibraryNode(Lang.get("lib_wires"))
                         .add(Ground.DESCRIPTION)
                         .add(VDD.DESCRIPTION)

src/main/java/de/neemann/digital/gui/components/EditorFactory.java

@@ -13,6 +13,7 @@ import de.neemann.digital.core.element.*;
 import de.neemann.digital.core.extern.Application;
 import de.neemann.digital.core.extern.PortDefinition;
 import de.neemann.digital.core.io.InValue;
+import de.neemann.digital.core.io.MIDIHelper;
 import de.neemann.digital.core.memory.DataField;
 import de.neemann.digital.core.memory.ROM;
 import de.neemann.digital.core.memory.importer.Importer;
@@ -94,6 +95,9 @@ public final class EditorFactory {
      * @return the editor
      */
     public <T> Editor<T> create(Key<T> key, T value) {
+        if (key == Keys.MIDI_INSTRUMENT)
+            return (Editor<T>) new MidiInstrumentEditor(value.toString());
+
         Class<? extends Editor> fac = map.get(key.getValueClass());
         if (fac == null)
             throw new RuntimeException("no editor found for " + key.getValueClass().getSimpleName());
@@ -1037,4 +1041,34 @@ public final class EditorFactory {
             romManager = value;
         }
     }
+
+    private static final class MidiInstrumentEditor extends LabelEditor<String> {
+        private JComboBox<String> comb;
+
+        private MidiInstrumentEditor(String instrument) {
+            String[] instruments;
+            try {
+                instruments = MIDIHelper.getInstance().getInstruments();
+            } catch (NodeException e) {
+                instruments = new String[]{"MIDI not available"};
+            }
+            comb = new JComboBox<>(instruments);
+            comb.setSelectedItem(instrument);
+        }
+
+        @Override
+        protected JComponent getComponent(ElementAttributes elementAttributes) {
+            return comb;
+        }
+
+        @Override
+        public String getValue() {
+            return (String) comb.getSelectedItem();
+        }
+
+        @Override
+        public void setValue(String value) {
+            comb.setSelectedItem(value);
+        }
+    }
 }

src/main/resources/lang/lang_de.xml

@@ -258,6 +258,15 @@
     <string name="elem_Terminal_pin_D">Über diesen Eingang werden die anzuzeigenden Daten an das Terminal weitergegeben.</string>
     <string name="elem_Terminal_pin_en">Ein High an diesem Eingang aktiviert den Takteingang.</string>
 
+    <string name="elem_MIDI">MIDI</string>
+    <string name="elem_MIDI_tt">Nutzt das MIDI-System, um Noten abzuspielen.</string>
+    <string name="elem_MIDI_pin_N">Note</string>
+    <string name="elem_MIDI_pin_V">Lautstärke</string>
+    <string name="elem_MIDI_pin_OnOff">Wenn gesetzt, enspricht das dem Drücken einer Keyboard-Taste (key down).
+        Wenn nicht gesetzt, entspricht das einem Loslassen der Taste (key up).</string>
+    <string name="elem_MIDI_pin_en">Wenn dieser eingang high ist, kann der Baustein angesprochen werden.</string>
+    <string name="elem_MIDI_pin_PC">Wenn gesetzt, wird mit dem Wert an Eingang N das Programm (Instrument) gewechselt.</string>
+    <string name="elem_MIDI_pin_C">Takteingang</string>
 
     <!-- Leitungen -->
 
@@ -993,6 +1002,10 @@ Sind evtl. die Namen der Variablen nicht eindeutig?</string>
     <string name="err_allMemoriesNeedToHaveTheSameByteWidth">Alle Speicher in welche Daten geladen werden sollen, benötigen die selbe Bitbreite.</string>
     <string name="err_ProgMemLabelsNotDifferent">Wenn Programme in mehrere RAMs geladen werden sollen, müssen alle RAMs
         unterschiedliche Bezeichnungen haben. Die lexikalische Ordnung legt dann die Reihenfolge der RAMs fest.</string>
+    <string name="err_midiSystemNotAvailable">Das MIDI-System ist nicht verfügbar.</string>
+    <string name="err_midiChannel_N_NotAvailable">Der MIDI-Kanal {0} ist nicht verfügbar.</string>
+    <string name="err_midiInstrument_N_NotAvailable">Das MIDI-Instrument {0} ist nicht verfügbar.</string>
+    <string name="err_midiInstrumentsNotAvailable">Die MIDI-Instrumente sind nicht verfügbar.</string>
 
     <string name="key_AddrBits">Adress-Bits</string><!-- ROM, RAMDualPort, RAMSinglePort, RAMSinglePortSel, EEPROM -->
     <string name="key_AddrBits_tt">Anzahl der Adress-Bits, die verwendet werden.</string>
@@ -1291,6 +1304,14 @@ Sind evtl. die Namen der Variablen nicht eindeutig?</string>
     <string name="key_textOrientation_LEFTCENTER">links mitte</string>
     <string name="key_textOrientation_CENTERCENTER">mitte mitte</string>
 
+    <string name="key_midiChannel">MIDI-Kanal</string>
+    <string name="key_midiChannel_tt">Legt den MIDI-Kanal fest.</string>
+    <string name="key_midiInstrument">MIDI-Instrument</string>
+    <string name="key_midiInstrument_tt">Das MIDI-Instrument, welches verwendet werden soll.</string>
+    <string name="key_midiProgChange">Programmwechsel erlauben</string>
+    <string name="key_midiProgChange_tt">Fügt einen weiteren Eingang PC hinzu. Wird dieser Eingang auf High gesetzt,
+        wird mit dem Wert am Eingang N das Programm (Instrument) gewechselt.</string>
+
     <string name="mod_insertWire">Leitung eingefügt.</string>
     <string name="mod_insertCopied">Aus Zwischenablage eingefügt.</string>
     <string name="mod_setKey_N0_in_element_N1">Wert ''{0}'' in Element ''{1}'' verändert.</string>

src/main/resources/lang/lang_en.xml

@@ -263,6 +263,15 @@
     <string name="elem_Terminal_pin_D">The data to write to the terminal</string>
     <string name="elem_Terminal_pin_en">A high at this input enables the clock input.</string>
 
+    <string name="elem_MIDI">MIDI</string>
+    <string name="elem_MIDI_tt">Uses the MIDI system to play notes.</string>
+    <string name="elem_MIDI_pin_N">Note</string>
+    <string name="elem_MIDI_pin_V">Volume</string>
+    <string name="elem_MIDI_pin_OnOff">If set, this translates to pressing a keyboard key (key down event),
+        if not set, this translates to releasing the key (key up event).</string>
+    <string name="elem_MIDI_pin_en">Enables the component</string>
+    <string name="elem_MIDI_pin_PC">If high, the value at N is used to change the program (instrument).</string>
+    <string name="elem_MIDI_pin_C">Clock</string>
 
     <!-- Wires -->
 
@@ -986,6 +995,10 @@
     <string name="err_allMemoriesNeedToHaveTheSameByteWidth">All memories into which data are to be loaded require the same bit width.</string>
     <string name="err_ProgMemLabelsNotDifferent">If programs are to be loaded into several RAMs, all RAMs must have
         different names. The lexical order then determines the order of the RAMs.</string>
+    <string name="err_midiSystemNotAvailable">The MIDI-System is not available.</string>
+    <string name="err_midiChannel_N_NotAvailable">The MIDI channel {0} is not available.</string>
+    <string name="err_midiInstrument_N_NotAvailable">The MIDI instrument {0} is not available.</string>
+    <string name="err_midiInstrumentsNotAvailable">The MIDI instruments are not available.</string>
 
     <string name="key_AddrBits">Address Bits</string><!-- ROM, RAMDualPort, RAMSinglePort, RAMSinglePortSel, EEPROM -->
     <string name="key_AddrBits_tt">Number of address bits used.</string>
@@ -1279,6 +1292,14 @@
     <string name="key_textOrientation_LEFTCENTER">left center</string>
     <string name="key_textOrientation_CENTERCENTER">center center</string>
 
+    <string name="key_midiChannel">MIDI channel</string>
+    <string name="key_midiChannel_tt">Selects the MIDI channel to use.</string>
+    <string name="key_midiInstrument">MIDI instrument</string>
+    <string name="key_midiInstrument_tt">The MIDI instrument to use.</string>
+    <string name="key_midiProgChange">Allow program change</string>
+    <string name="key_midiProgChange_tt">Adds  a new input PC. If this input is set to high,
+        the value at input N is used to change te program (instrument).</string>
+
     <string name="mod_insertWire">Inserted wire.</string>
     <string name="mod_insertCopied">Insert from clipboard.</string>
     <string name="mod_setKey_N0_in_element_N1">Value ''{0}'' in component ''{1}'' modified.</string>

src/test/java/de/neemann/digital/integration/TestExamples.java

@@ -32,7 +32,7 @@ public class TestExamples extends TestCase {
      */
     public void testDistExamples() throws Exception {
         File examples = new File(Resources.getRoot().getParentFile().getParentFile(), "/main/dig");
-        assertEquals(248, new FileScanner(this::check).scan(examples));
+        assertEquals(250, new FileScanner(this::check).scan(examples));
         assertEquals(170, testCasesInFiles);
     }
 

src/test/resources/dig/backtrack/AllComponents.dig

@@ -579,6 +579,31 @@
       <elementAttributes/>
       <pos x="120" y="900"/>
     </visualElement>
+    <visualElement>
+      <elementName>Const</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Bits</string>
+          <int>7</int>
+        </entry>
+      </elementAttributes>
+      <pos x="280" y="940"/>
+    </visualElement>
+    <visualElement>
+      <elementName>Const</elementName>
+      <elementAttributes>
+        <entry>
+          <string>Bits</string>
+          <int>7</int>
+        </entry>
+      </elementAttributes>
+      <pos x="280" y="960"/>
+    </visualElement>
+    <visualElement>
+      <elementName>MIDI</elementName>
+      <elementAttributes/>
+      <pos x="300" y="940"/>
+    </visualElement>
   </visualElements>
   <wires>
     <wire>
@@ -625,6 +650,10 @@
       <p1 x="400" y="960"/>
       <p2 x="420" y="960"/>
     </wire>
+    <wire>
+      <p1 x="280" y="960"/>
+      <p2 x="300" y="960"/>
+    </wire>
     <wire>
       <p1 x="240" y="260"/>
       <p2 x="260" y="260"/>
@@ -773,6 +802,10 @@
       <p1 x="400" y="400"/>
       <p2 x="440" y="400"/>
     </wire>
+    <wire>
+      <p1 x="440" y="400"/>
+      <p2 x="460" y="400"/>
+    </wire>
     <wire>
       <p1 x="460" y="400"/>
       <p2 x="480" y="400"/>
@@ -781,10 +814,6 @@
       <p1 x="480" y="400"/>
       <p2 x="500" y="400"/>
     </wire>
-    <wire>
-      <p1 x="440" y="400"/>
-      <p2 x="460" y="400"/>
-    </wire>
     <wire>
       <p1 x="1080" y="1040"/>
       <p2 x="1120" y="1040"/>
@@ -805,6 +834,14 @@
       <p1 x="240" y="660"/>
       <p2 x="260" y="660"/>
     </wire>
+    <wire>
+      <p1 x="240" y="980"/>
+      <p2 x="280" y="980"/>
+    </wire>
+    <wire>
+      <p1 x="280" y="980"/>
+      <p2 x="300" y="980"/>
+    </wire>
     <wire>
       <p1 x="380" y="920"/>
       <p2 x="420" y="920"/>
@@ -973,6 +1010,10 @@
       <p1 x="1140" y="360"/>
       <p2 x="1160" y="360"/>
     </wire>
+    <wire>
+      <p1 x="280" y="1000"/>
+      <p2 x="300" y="1000"/>
+    </wire>
     <wire>
       <p1 x="1080" y="940"/>
       <p2 x="1100" y="940"/>
@@ -985,6 +1026,10 @@
       <p1 x="400" y="940"/>
       <p2 x="420" y="940"/>
     </wire>
+    <wire>
+      <p1 x="280" y="940"/>
+      <p2 x="300" y="940"/>
+    </wire>
     <wire>
       <p1 x="1080" y="620"/>
       <p2 x="1100" y="620"/>
@@ -1105,6 +1150,14 @@
       <p1 x="180" y="180"/>
       <p2 x="240" y="180"/>
     </wire>
+    <wire>
+      <p1 x="1120" y="180"/>
+      <p2 x="1140" y="180"/>
+    </wire>
+    <wire>
+      <p1 x="580" y="180"/>
+      <p2 x="780" y="180"/>
+    </wire>
     <wire>
       <p1 x="400" y="180"/>
       <p2 x="580" y="180"/>
@@ -1113,10 +1166,6 @@
       <p1 x="780" y="180"/>
       <p2 x="900" y="180"/>
     </wire>
-    <wire>
-      <p1 x="1120" y="180"/>
-      <p2 x="1140" y="180"/>
-    </wire>
     <wire>
       <p1 x="1080" y="180"/>
       <p2 x="1120" y="180"/>
@@ -1129,10 +1178,6 @@
       <p1 x="240" y="180"/>
       <p2 x="400" y="180"/>
     </wire>
-    <wire>
-      <p1 x="580" y="180"/>
-      <p2 x="780" y="180"/>
-    </wire>
     <wire>
       <p1 x="1080" y="760"/>
       <p2 x="1100" y="760"/>
@@ -1193,6 +1238,10 @@
       <p1 x="940" y="380"/>
       <p2 x="960" y="380"/>
     </wire>
+    <wire>
+      <p1 x="280" y="1020"/>
+      <p2 x="300" y="1020"/>
+    </wire>
     <wire>
       <p1 x="640" y="500"/>
       <p2 x="640" y="520"/>
@@ -1461,6 +1510,14 @@
       <p1 x="920" y="100"/>
       <p2 x="920" y="620"/>
     </wire>
+    <wire>
+      <p1 x="280" y="980"/>
+      <p2 x="280" y="1000"/>
+    </wire>
+    <wire>
+      <p1 x="280" y="1000"/>
+      <p2 x="280" y="1020"/>
+    </wire>
     <wire>
       <p1 x="220" y="220"/>
       <p2 x="220" y="300"/>
@@ -1613,6 +1670,10 @@
       <p1 x="240" y="340"/>
       <p2 x="240" y="420"/>
     </wire>
+    <wire>
+      <p1 x="240" y="880"/>
+      <p2 x="240" y="980"/>
+    </wire>
     <wire>
       <p1 x="240" y="420"/>
       <p2 x="240" y="500"/>