Added double buffering 2

Core/Cpu/Z80.cs

@@ -1596,7 +1596,7 @@ namespace Core.Cpu
                         if ((n & 0x02) != 0) AF.Low |= 0x20;
                         return 16;
                     }
-                case 0xA9: // CPD (The opcode that just crashed!)
+                case 0xA9: // CPD 
                     {
                         byte memVal = ReadMemory(HL.Word);
                         byte result = (byte)(AF.High - memVal);

Core/Io/ULA.cs

@@ -11,7 +11,7 @@ namespace Core.Io
         // The ULA owns the frame buffer now!
         public const int ScreenWidth = 320;
         public const int ScreenHeight = 256; // Perfectly cropped size
-        public int[] FrameBuffer { get; private set; }
+        public int[] FrameBuffer { get; private set; } = new int[ScreenWidth * ScreenHeight];
         public int[] FrontBuffer { get; private set; } = new int[ScreenWidth * ScreenHeight];
 
         private int _ulaFrameCount = 0;

Desktop/Form1.cs

@@ -170,6 +170,7 @@ namespace Desktop
                             if (scanlineCount % 312 == 0)
                             {
                                 _cpu.RequestInterrupt(); // 50Hz interrupt
+                                _ula.CommitFrame();
                                 TotalFrameCount++;
 
                                 if (highSpeed)