Intellivision implement BackTab calls

Correct timing for background drawing, not sure if any game uses it though

BizHawk.Emulation.Cores/Consoles/Intellivision/Intellivision.IEmulator.cs

@@ -25,11 +25,12 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			_psg.sample_count = 0;
 
 			_frame++;
+			stic_row = -1;
 			// read the controller state here for now
 			get_controller_state();
 
 			// this timer tracks cycles stolen by the STIC during the visible part of the frame, quite a large number of them actually
-			int delay_cycles = 0; 
+			int delay_cycles = 600; 
 			int delay_timer = -1;
 
 			_cpu.PendingCycles = (14934 - 3791 + _cpu.GetPendingCycles());
@@ -53,13 +54,19 @@ namespace BizHawk.Emulation.Cores.Intellivision
 					}
 				}
 
-				if (delay_cycles>= 800 && _stic.active_display)
+				if (delay_cycles>= 750 && _stic.active_display)
 				{
 					delay_cycles = -1;
 					delay_timer = 110;
 					_stic.ToggleSr2();
+					if (stic_row >= 0)
+					{
+						_stic.in_vb_2 = true;
+						_stic.Background(stic_row);
+						_stic.in_vb_2 = false;
+					}					
+					stic_row++;
 				}
-
 				Connect();
 			}
 
@@ -69,7 +76,6 @@ namespace BizHawk.Emulation.Cores.Intellivision
 
 			if (_stic.active_display)
 			{
-				_stic.Background();
 				_stic.Mobs();
 			}
 
@@ -100,6 +106,7 @@ namespace BizHawk.Emulation.Cores.Intellivision
 		}
 
 		private int _frame;
+		private int stic_row;
 		public int Frame { get { return _frame; } }
 
 		public string SystemId

BizHawk.Emulation.Cores/Consoles/Intellivision/Intellivision.IStatable.cs

@@ -1,56 +1,57 @@
-using System.IO;
+using System.IO;
-
+
-using BizHawk.Common;
+using BizHawk.Common;
-using BizHawk.Emulation.Common;
+using BizHawk.Emulation.Common;
-
+
-
+
-namespace BizHawk.Emulation.Cores.Intellivision
+namespace BizHawk.Emulation.Cores.Intellivision
-{
+{
-	public partial class Intellivision : IStatable
+	public partial class Intellivision : IStatable
-	{
+	{
-		public bool BinarySaveStatesPreferred
+		public bool BinarySaveStatesPreferred
-		{
+		{
-			get { return true; }
+			get { return true; }
-		}
+		}
-
+
-		public void SaveStateText(TextWriter writer)
+		public void SaveStateText(TextWriter writer)
-		{
+		{
-			SyncState(Serializer.CreateTextWriter(writer));
+			SyncState(Serializer.CreateTextWriter(writer));
-		}
+		}
-
+
-		public void LoadStateText(TextReader reader)
+		public void LoadStateText(TextReader reader)
-		{
+		{
-			SyncState(Serializer.CreateTextReader(reader));
+			SyncState(Serializer.CreateTextReader(reader));
-			SetupMemoryDomains(); // resync the memory domains
+			SetupMemoryDomains(); // resync the memory domains
-		}
+		}
-
+
-		public void SaveStateBinary(BinaryWriter bw)
+		public void SaveStateBinary(BinaryWriter bw)
-		{
+		{
-			SyncState(Serializer.CreateBinaryWriter(bw));
+			SyncState(Serializer.CreateBinaryWriter(bw));
-		}
+		}
-
+
-		public void LoadStateBinary(BinaryReader br)
+		public void LoadStateBinary(BinaryReader br)
-		{
+		{
-			SyncState(Serializer.CreateBinaryReader(br));
+			SyncState(Serializer.CreateBinaryReader(br));
-			SetupMemoryDomains(); // resync the memory domains
+			SetupMemoryDomains(); // resync the memory domains
-		}
+		}
-
+
-		public byte[] SaveStateBinary()
+		public byte[] SaveStateBinary()
-		{
+		{
-			MemoryStream ms = new MemoryStream();
+			MemoryStream ms = new MemoryStream();
-			BinaryWriter bw = new BinaryWriter(ms);
+			BinaryWriter bw = new BinaryWriter(ms);
-			SaveStateBinary(bw);
+			SaveStateBinary(bw);
-			bw.Flush();
+			bw.Flush();
-			return ms.ToArray();
+			return ms.ToArray();
-		}
+		}
-
+
-		private void SyncState(Serializer ser)
+		private void SyncState(Serializer ser)
-		{
+		{
-			int version = 1;
+			int version = 1;
-			ser.BeginSection("Intellivision");
+			ser.BeginSection("Intellivision");
-			ser.Sync("version", ref version);
+			ser.Sync("version", ref version);
-			ser.Sync("Frame", ref _frame);
+			ser.Sync("Frame", ref _frame);
-
+			ser.Sync("stic_row", ref stic_row);
+
 			ser.Sync("ScratchpadRam", ref ScratchpadRam, false);
 			ser.Sync("SystemRam", ref SystemRam, false);
 			ser.Sync("ExecutiveRom", ref ExecutiveRom, false);
@@ -59,13 +60,13 @@ namespace BizHawk.Emulation.Cores.Intellivision
 
 
 
-			_cpu.SyncState(ser);
+			_cpu.SyncState(ser);
-			_stic.SyncState(ser);
+			_stic.SyncState(ser);
-			_psg.SyncState(ser);
+			_psg.SyncState(ser);
-			_cart.SyncState(ser);
+			_cart.SyncState(ser);
-			ControllerDeck.SyncState(ser);
+			ControllerDeck.SyncState(ser);
-
+
-			ser.EndSection();
+			ser.EndSection();
-		}
+		}
-	}
+	}
-}
+}

BizHawk.Emulation.Cores/Consoles/Intellivision/STIC.cs

@@ -319,7 +319,7 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			throw new ArgumentException("Specified color does not exist.");
 		}
 
-		public void Background()
+		public void Background(int input_row)
 		{
 			// here we will also need to apply the 'delay' register values.
 			// this shifts the background portion of the screen relative to the mobs
@@ -328,7 +328,7 @@ namespace BizHawk.Emulation.Cores.Intellivision
 			ColorSP = 0x0028;
 			
 			// The background is a 20x12 grid of "cards".
-			for (int card_row = 0; card_row < 12; card_row++)
+			for (int card_row = input_row; card_row < (input_row+1); card_row++)
 			{
 				for (int card_col = 0; card_col < 20; card_col++)
 				{