#2 Started implementing the VIC-II

ComputerSystems/Commodore64/Commodore64.csproj

@@ -74,6 +74,7 @@
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Settings.cs" />
+    <Compile Include="VicIi.cs" />
     <EmbeddedResource Include="FormC64Screen.resx">
       <DependentUpon>FormC64Screen.cs</DependentUpon>
     </EmbeddedResource>

ComputerSystems/Commodore64/VicIi.cs

@@ -0,0 +1,71 @@
+using Hardware.Memory;
+using System.Drawing;
+
+namespace Commodore64 {
+    public class VicIi {
+
+        public enum TvSystem {
+            NTSC,
+            PAL
+        }
+
+        public TvSystem CurrentTvSystem = TvSystem.PAL;
+
+        public const int FULL_WIDTH = 504;
+        public const int FULL_WIDTH_CYCLES = 63;
+        public const int USABLE_WIDTH_BORDER = 403;
+        public const int USABLE_WIDTH = 320;
+        public const int USABLE_WIDTH_CYCLES = 40;
+
+        public const int FULL_HEIGHT_NTSC = 262;
+        public const int FULL_HEIGHT_PAL = 312;
+        public const int USABLE_HEIGHT = 200;
+        public const int USABLE_HEIGHT_BORDER = 284;
+        public int CurrentLine = 0;
+        public int CurrentLineCycle = 0;
+
+        public int TotalCycles = 0;
+
+        public Color[] ScreenBufferPixels = new Color[USABLE_WIDTH_BORDER * USABLE_HEIGHT_BORDER];
+
+        public bool ScreenOn => (Read(0xD011) & 0b00010000) == 1;
+
+
+        private readonly IMemory<byte> _bus;
+
+
+        public VicIi(IMemory<byte> bus) {
+            _bus = bus;
+        }
+
+        public void Cycle() {
+
+
+            CurrentLineCycle++;
+
+            if (CurrentLineCycle == 64) {
+                CurrentLineCycle = 0;
+
+                CurrentLine++;
+
+                if ((CurrentTvSystem == TvSystem.PAL && CurrentLine == FULL_HEIGHT_PAL) || 
+                    (CurrentTvSystem == TvSystem.NTSC && CurrentLine == FULL_HEIGHT_NTSC)) {
+
+                    CurrentLine = 0;
+                }
+            }
+
+            UpdateScreenBufferPixels();
+
+            TotalCycles++;
+        }
+
+        private void UpdateScreenBufferPixels() {
+
+        }
+
+        public byte Read(int address) {
+            return _bus[address];
+        }
+    }
+}