commodore64: PRG loading uses a more robust method

BizHawk.Emulation/BizHawk.Emulation.csproj

@@ -83,6 +83,7 @@
     <Compile Include="Computers\Commodore64\C64.cs" />
     <Compile Include="Computers\Commodore64\Cartridges\Mapper0000.cs" />
     <Compile Include="Computers\Commodore64\C64.Input.cs" />
+    <Compile Include="Computers\Commodore64\Media\PRG.cs" />
     <Compile Include="Computers\Commodore64\Memory.cs" />
     <Compile Include="Computers\Commodore64\Cartridges\Cartridge.cs" />
     <Compile Include="Computers\Commodore64\MOS\CartridgePort.cs" />

BizHawk.Emulation/Computers/Commodore64/C64.Core.cs

@@ -31,7 +31,11 @@ namespace BizHawk.Emulation.Computers.Commodore64
 	{
 		// ------------------------------------
 
-		C64Chips chips;
+		private C64Chips chips;
+
+		// ------------------------------------
+
+		private bool loadPrg;
 
 		// ------------------------------------
 
@@ -62,6 +66,10 @@ namespace BizHawk.Emulation.Computers.Commodore64
 						chips.pla.Game = chips.cartPort.Game;
 					}
 					break;
+				case @".PRG":
+					if (inputFile.Length > 2)
+						loadPrg = true;
+					break;
 			}
 		}
 

BizHawk.Emulation/Computers/Commodore64/C64.cs

@@ -90,6 +90,21 @@ namespace BizHawk.Emulation.Computers.Commodore64
 		// process frame
 		public void FrameAdvance(bool render, bool rendersound)
 		{
+			// load PRG file if needed
+			if (loadPrg)
+			{
+				if (chips.pla.Peek(0x04C8) == 0x12 &&
+					chips.pla.Peek(0x04C9) == 0x05 &&
+					chips.pla.Peek(0x04CA) == 0x01 &&
+					chips.pla.Peek(0x04CB) == 0x04 &&
+					chips.pla.Peek(0x04CC) == 0x19 &&
+					chips.pla.Peek(0x04CD) == 0x2E)
+				{
+					Media.PRG.Load(chips.pla, inputFile);
+					loadPrg = false;
+				}
+			}
+
 			PollInput();
 			chips.pla.InputWasRead = false;
 			Execute(cyclesPerFrame);

BizHawk.Emulation/Computers/Commodore64/Media/D64.cs

@@ -4,7 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 
-namespace BizHawk.Emulation.Computers.Commodore64
+namespace BizHawk.Emulation.Computers.Commodore64.Media
 {
 	public static class D64
 	{

BizHawk.Emulation/Computers/Commodore64/Media/Disk.cs

@@ -3,7 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
-namespace BizHawk.Emulation.Computers.Commodore64
+namespace BizHawk.Emulation.Computers.Commodore64.Media
 {
 	public class Track
 	{

BizHawk.Emulation/Computers/Commodore64/Media/G64.cs

@@ -4,7 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Text;
 
-namespace BizHawk.Emulation.Computers.Commodore64
+namespace BizHawk.Emulation.Computers.Commodore64.Media
 {
 	public static class G64
 	{

BizHawk.Emulation/Computers/Commodore64/Media/PRG.cs

@@ -0,0 +1,30 @@
+using BizHawk.Emulation.Computers.Commodore64.MOS;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace BizHawk.Emulation.Computers.Commodore64.Media
+{
+	public static class PRG
+	{
+		static public void Load(MOSPLA pla, byte[] prgFile)
+		{
+			uint length = (uint)prgFile.Length;
+			if (length > 2)
+			{
+				ushort addr = (ushort)(prgFile[0] | (prgFile[1] << 8));
+				uint offset = 2;
+				unchecked
+				{
+					while (offset < length)
+					{
+						pla.Write(addr, prgFile[offset]);
+						offset++;
+						addr++;
+					}
+				}
+			}
+		}
+	}
+}