Vectrex: Implement 64K bank switching, add some homebrews to DB

Assets/gamedb/gamedb_vectrex.txt

@@ -23,4 +23,9 @@
 
 ;;; Actually TRANSLATED
 
-;;; Games NOT present in TOSEC
+;;; Games NOT present in TOSEC
+
+;;; Homebrew
+SHA1:D2FB28CECC38202E17BEE2FAEBC93B3BC8B76AFD		Where Have All The Pixels Gone?	VEC
+SHA1:CF5DF39705107732CAF81C7FE742A5AEE598E9BC		EigenVectrex	VEC
+

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/HW_Registers.cs

@@ -157,7 +157,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 					if (dir_ctrl.Bit(3)) { bc1 = value.Bit(3); }
 					if (dir_ctrl.Bit(4)) { bdir = value.Bit(4); }
 					if (dir_ctrl.Bit(5)) { /*compare = value.Bit(5);*/ }
-					if (dir_ctrl.Bit(6)) { /* cart bank switch */ }
+					if (dir_ctrl.Bit(6)) { /*writing here seems to change the bank for only a single cycle, and only in output mode, not implemented*/ }
 					if (dir_ctrl.Bit(7))
 					{
 						//Console.WriteLine(PB7_undriven + " " + !wrt_val.Bit(7));
@@ -326,6 +326,9 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 					break;
 				case 0x2:
 					dir_ctrl = value;
+					// the direction of bit 6 here controls the bank
+					mapper.bank = dir_ctrl.Bit(6) ? 1 : 0;
+
 					break;
 				case 0x3:
 					dir_dac = value;

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/Mappers/MapperBase.cs

@@ -7,6 +7,8 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 	{
 		public VectrexHawk Core { get; set; }
 
+		public int bank;
+
 		public virtual byte ReadMemory(ushort addr)
 		{
 			return 0;
@@ -27,6 +29,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 
 		public virtual void SyncState(Serializer ser)
 		{
+			ser.Sync(nameof(bank), ref bank);
 		}
 
 		public virtual void Dispose()

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/Mappers/Mapper_64K.cs

@@ -0,0 +1,32 @@
+namespace BizHawk.Emulation.Cores.Consoles.Vectrex
+{
+	// Default mapper with no bank switching
+	// make sure peekmemory and poke memory don't effect the rest of the system!
+	public class Mapper_64K : MapperBase
+	{
+		public override void Initialize()
+		{
+			bank = 0;
+		}
+
+		public override byte ReadMemory(ushort addr)
+		{
+			return Core._rom[addr + bank * 0x8000];
+		}
+
+		public override byte PeekMemory(ushort addr)
+		{
+			return ReadMemory(addr);
+		}
+
+		public override void WriteMemory(ushort addr, byte value)
+		{
+
+		}
+
+		public override void PokeMemory(ushort addr, byte value)
+		{
+			WriteMemory(addr, value);
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/GCE/Vectrex/VectrexHawk.cs

@@ -62,7 +62,7 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 
 			_rom = rom;
 
-			// If the game is minstorm, then no cartridge is inserted, retun 0xFF
+			// If the game is minestorm, then no cartridge is inserted, retun 0xFF
 			if (romHashSHA1 == RomChecksums.Minestorm)
 			{
 				_rom  = new byte[0x8000];
@@ -159,8 +159,17 @@ namespace BizHawk.Emulation.Cores.Consoles.Vectrex
 
 		private void Setup_Mapper()
 		{
-			mapper = new MapperDefault();
+			if (_rom.Length == 0x10000)
+			{
+				mapper = new Mapper_64K();
+			}
+			else
+			{
+				mapper = new MapperDefault();
+			}
+			
 			mapper.Core = this;
+			mapper.Initialize();
 		}
 	}
 }