New hardware implementation:

- Orbit controller: implemented and passes ROS-less diagnostics
- ROS: In progress, not functional
- DAC: For Ted Kaehler's Smalltalk Music system (FM and Sampling).  Works, generates audio and can capture to WAV file.
- Organ keybard: Stub, enough implemented to make the music system happy (so it will play back music and not crash.)

Some minor cleanup.

New dependency on NAudio package for DAC playback.  Installer updated to include NAudio lib.

Contralto/AltoSystem.cs

@@ -37,13 +37,15 @@ namespace Contralto
             _scheduler = new Scheduler();
             
             _memBus = new MemoryBus();
-            _mem = new Memory.Memory();            
+            _mem = new Memory.Memory();
             _keyboard = new Keyboard();
             _diskController = new DiskController(this);
             _displayController = new DisplayController(this);
             _mouse = new Mouse();
             _ethernetController = new EthernetController(this);
-            _musicInterface = new Music(this);
+            _orbitController = new OrbitController(this);
+            _audioDAC = new AudioDAC(this);
+            _organKeyboard = new OrganKeyboard(this);
 
             _cpu = new AltoCPU(this);
 
@@ -51,9 +53,10 @@ namespace Contralto
             _memBus.AddDevice(_mem);
             _memBus.AddDevice(_keyboard);
             _memBus.AddDevice(_mouse);
-            _memBus.AddDevice(_musicInterface);            
+            _memBus.AddDevice(_audioDAC);
+            _memBus.AddDevice(_organKeyboard);
 
-            Reset();           
+            Reset();
         }
 
         public void Reset()
@@ -70,9 +73,9 @@ namespace Contralto
             _mouse.Reset();
             _cpu.Reset();
             _ethernetController.Reset();
-            _musicInterface.Reset();
+            _orbitController.Reset();            
 
-            UCodeMemory.Reset();            
+            UCodeMemory.Reset();
         }
 
         /// <summary>
@@ -81,7 +84,7 @@ namespace Contralto
         /// <param name="d"></param>
         public void AttachDisplay(IAltoDisplay d)
         {
-            _displayController.AttachDisplay(d);           
+            _displayController.AttachDisplay(d);
         }
 
         public void DetachDisplay()
@@ -96,11 +99,16 @@ namespace Contralto
             {
                 _ethernetController.HostInterface.Shutdown();
             }
+
+            //
+            // Allow the DAC to flush its output
+            //
+            _audioDAC.Shutdown();
         }
 
         public void SingleStep()
         {
-            // Run every device that needs attention for a single clock cycle.           
+            // Run every device that needs attention for a single clock cycle.
             _memBus.Clock();
             _cpu.Clock();
 
@@ -224,6 +232,11 @@ namespace Contralto
             get { return _ethernetController; }
         }
 
+        public OrbitController OrbitController
+        {
+            get { return _orbitController; }
+        }
+
         public Scheduler Scheduler
         {
             get { return _scheduler; }
@@ -239,7 +252,9 @@ namespace Contralto
         private DiskController _diskController;
         private DisplayController _displayController;
         private EthernetController _ethernetController;
-        private Music _musicInterface;
+        private OrbitController _orbitController;
+        private AudioDAC _audioDAC;
+        private OrganKeyboard _organKeyboard;
 
         private Scheduler _scheduler;
     }