Atari 2600 - some ground work for the AR mapper, doesn't yet do anything

BizHawk.Emulation.Cores/Consoles/Atari/2600/Mappers/mAR.cs

@@ -8,19 +8,114 @@ using BizHawk.Common;
 
   The Supercharger has four 2K banks.  There are three banks of RAM 
   and one bank of ROM.  All 6K of the RAM can be read and written.
+ 
+  D7-D5 of this byte: Write Pulse Delay (n/a for emulator)
+  
+  D4-D0: RAM/ROM configuration:
+        $F000-F7FF    $F800-FFFF Address range that banks map into
+   000wp     2            ROM
+   001wp     0            ROM
+   010wp     2            0      as used in Commie Mutants and many others
+   011wp     0            2      as used in Suicide Mission
+   100wp     2            ROM
+   101wp     1            ROM
+   110wp     2            1      as used in Killer Satellites
+   111wp     1            2      as we use for 2k/4k ROM cloning
+  
+   w = Write Enable (1 = enabled; accesses to $F000-$F0FF cause writes
+     to happen.  0 = disabled, and the cart acts like ROM.)
+   p = ROM Power (0 = enabled, 1 = off.)  Only power the ROM if you're
+     wanting to access the ROM for multiloads.  Otherwise set to 1.
 */
 namespace BizHawk.Emulation.Cores.Atari.Atari2600
 {
 	internal class mAR : MapperBase
 	{
-		private int _bank4k;
-		private ByteBuffer _ram = new ByteBuffer(6144);
-
 		public mAR()
 		{
 			throw new NotImplementedException();
 		}
 
+		private int _bank2k;
+		private ByteBuffer _ram = new ByteBuffer(6144);
+		private IntBuffer _offsets = new IntBuffer(2);
+		private bool _writePending = false;
+
+		private readonly byte[] _RomCode = {
+			0xa5, 0xfa, 0x85, 0x80, 0x4c, 0x18, 0xf8, 0xff,
+			0xff, 0xff, 0x78, 0xd8, 0xa0, 0x00, 0xa2, 0x00,
+			0x94, 0x00, 0xe8, 0xd0, 0xfb, 0x4c, 0x50, 0xf8,
+			0xa2, 0x00, 0xbd, 0x06, 0xf0, 0xad, 0xf8, 0xff,
+			0xa2, 0x00, 0xad, 0x00, 0xf0, 0xea, 0xbd, 0x00,
+			0xf7, 0xca, 0xd0, 0xf6, 0x4c, 0x50, 0xf8, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xa2, 0x03, 0xbc, 0x22, 0xf9, 0x94, 0xfa, 0xca,
+			0x10, 0xf8, 0xa0, 0x00, 0xa2, 0x28, 0x94, 0x04,
+			0xca, 0x10, 0xfb, 0xa2, 0x1c, 0x94, 0x81, 0xca,
+			0x10, 0xfb, 0xa9, 0xff, 0xc9, 0x00, 0xd0, 0x03,
+			0x4c, 0x13, 0xf9, 0xa9, 0x00, 0x85, 0x1b, 0x85,
+			0x1c, 0x85, 0x1d, 0x85, 0x1e, 0x85, 0x1f, 0x85,
+			0x19, 0x85, 0x1a, 0x85, 0x08, 0x85, 0x01, 0xa9,
+			0x10, 0x85, 0x21, 0x85, 0x02, 0xa2, 0x07, 0xca,
+			0xca, 0xd0, 0xfd, 0xa9, 0x00, 0x85, 0x20, 0x85,
+			0x10, 0x85, 0x11, 0x85, 0x02, 0x85, 0x2a, 0xa9,
+			0x05, 0x85, 0x0a, 0xa9, 0xff, 0x85, 0x0d, 0x85,
+			0x0e, 0x85, 0x0f, 0x85, 0x84, 0x85, 0x85, 0xa9,
+			0xf0, 0x85, 0x83, 0xa9, 0x74, 0x85, 0x09, 0xa9,
+			0x0c, 0x85, 0x15, 0xa9, 0x1f, 0x85, 0x17, 0x85,
+			0x82, 0xa9, 0x07, 0x85, 0x19, 0xa2, 0x08, 0xa0,
+			0x00, 0x85, 0x02, 0x88, 0xd0, 0xfb, 0x85, 0x02,
+			0x85, 0x02, 0xa9, 0x02, 0x85, 0x02, 0x85, 0x00,
+			0x85, 0x02, 0x85, 0x02, 0x85, 0x02, 0xa9, 0x00,
+			0x85, 0x00, 0xca, 0x10, 0xe4, 0x06, 0x83, 0x66,
+			0x84, 0x26, 0x85, 0xa5, 0x83, 0x85, 0x0d, 0xa5,
+			0x84, 0x85, 0x0e, 0xa5, 0x85, 0x85, 0x0f, 0xa6,
+			0x82, 0xca, 0x86, 0x82, 0x86, 0x17, 0xe0, 0x0a,
+			0xd0, 0xc3, 0xa9, 0x02, 0x85, 0x01, 0xa2, 0x1c,
+			0xa0, 0x00, 0x84, 0x19, 0x84, 0x09, 0x94, 0x81,
+			0xca, 0x10, 0xfb, 0xa6, 0x80, 0xdd, 0x00, 0xf0,
+			0xa9, 0x9a, 0xa2, 0xff, 0xa0, 0x00, 0x9a, 0x4c,
+			0xfa, 0x00, 0xcd, 0xf8, 0xff, 0x4c
+		};
+
+		private readonly byte[] RomHeader = {
+			0xac, 0xfa, 0x0f, 0x18, 0x62, 0x00, 0x24, 0x02,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0x00, 0x04, 0x08, 0x0c, 0x10, 0x14, 0x18, 0x1c,
+			0x01, 0x05, 0x09, 0x0d, 0x11, 0x15, 0x19, 0x1d,
+			0x02, 0x06, 0x0a, 0x0e, 0x12, 0x16, 0x1a, 0x1e,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+			0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00
+		};
+
 		public override bool HasCartRam
 		{
 			get { return true; }
@@ -34,13 +129,13 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 		public override void SyncState(Serializer ser)
 		{
 			base.SyncState(ser);
-			ser.Sync("bank4k", ref _bank4k);
+			ser.Sync("bank4k", ref _bank2k);
 			ser.Sync("ram", ref _ram);
 		}
 
 		public override void HardReset()
 		{
-			_bank4k = 0;
+			_bank2k = 0;
 			_ram = new ByteBuffer(6144);
 			base.HardReset();
 		}
@@ -63,7 +158,22 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 				return base.ReadMemory(addr);
 			}
 
-			return Core.Rom[(_bank4k << 12) + (addr & 0xFFF)];
+			if (addr == 0x1850 && _offsets[1] == (3 << 11))
+			{
+				/// TODO: weird stuff goes here
+				/// 
+				return Core.Rom[(addr & 0x7FF) + _offsets[1]];
+			}
+
+			// TODO: cancel pending writes
+			if (addr == 0x1FF8)
+			{
+				_writePending = false;
+
+			}
+
+
+			return Core.Rom[(_bank2k << 12) + (addr & 0xFFF)];
 		}
 
 		public override byte ReadMemory(ushort addr)
@@ -80,11 +190,11 @@ namespace BizHawk.Emulation.Cores.Atari.Atari2600
 		{
 			if (addr == 0x1FF8)
 			{
-				_bank4k = 0;
+				_bank2k = 0;
 			}
 			else if (addr == 0x1FF9)
 			{
-				_bank4k = 1;
+				_bank2k = 1;
 			}
 		}
 	}