Start mapper 107

BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Mapper107.cs

@@ -0,0 +1,63 @@
+using System;
+using System.IO;
+using System.Diagnostics;
+
+namespace BizHawk.Emulation.Consoles.Nintendo
+{
+/*
+Registers:
+---------------------------
+I do not know whether or not this mapper suffers from bus conflicts.  Use caution!
+
+  $8000-FFFF:  [PPPP PPP.]
+               [CCCC CCCC]
+    P = Selects 32k PRG @ $8000
+    C = Selects 8k CHR @ $0000
+
+This is very strange.  Bits 1-7 seem to be used by both CHR and PRG.
+ 
+Games:
+    Magic Dragon
+*/
+
+    class Mapper107 : NES.NESBoardBase
+    {
+        int prg, chr;
+        public override bool Configure(NES.EDetectionOrigin origin)
+        {
+            //configure
+			switch (Cart.board_type)
+			{
+				case "Mapper107":
+					break;
+				default:
+					return false;
+			}
+            return true;
+        }
+
+        public override byte ReadPPU(int addr)
+        {
+            return VRAM[addr + (chr * 0x2000)];
+        }
+
+        public override byte ReadPRG(int addr)
+        {
+            return VROM[addr + (prg * 0x8000)];
+        }
+
+        public override void WriteWRAM(int addr, byte value)
+        {
+            chr = value;
+            prg = addr >> 1;
+            base.WriteWRAM(addr, value);
+        }
+
+		public override void SyncState(Serializer ser)
+        {
+			base.SyncState(ser);
+            ser.Sync("prg", ref prg);
+            ser.Sync("chr", ref chr);
+        }
+    }
+}