From 1ac5ce1bfb336daeb14913db67140f3b24055a4f Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@zeromus.org>
Date: Mon, 5 Mar 2012 18:21:17 +0000
Subject: [PATCH] nes-fix taito_x1_005

---
 .../Nintendo/NES/Boards/Taito_X1_005.cs       | 24 ++++++++++++-------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
index d8bc1a73ba..f289f05f58 100644
--- a/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
+++ b/BizHawk.Emulation/Consoles/Nintendo/NES/Boards/Taito_X1_005.cs
@@ -74,7 +74,7 @@ PRG Setup:
 			}
 
 			SetMirrorType(EMirrorType.Vertical);
-			chr_bank_mask = Cart.chr_size / 2 - 1;
+			chr_bank_mask = Cart.chr_size / 1 - 1;
 			prg_bank_mask = Cart.prg_size / 8 - 1;
 			prg_regs_8k[3] = 0xFF;
 			return true;
@@ -92,10 +92,12 @@ PRG Setup:
 					break;
 
 				case 0x1EF0:
-					chr_regs_1k[0] = value;
+					chr_regs_1k[0] = (byte)(value/2*2);
+					chr_regs_1k[1] = (byte)(value/2*2+1);
 					break;
 				case 0x1EF1:
-					chr_regs_1k[2] = value;
+					chr_regs_1k[2] = (byte)(value/2*2);
+					chr_regs_1k[3] = (byte)(value/2*2+1);
 					break;
 				
 				case 0x1EF2:
@@ -138,12 +140,16 @@ PRG Setup:
 
 		public override byte ReadPPU(int addr)
 		{
-			int bank_2k = addr >> 11;
-			int ofs = addr & ((1 << 11) - 1);
-			bank_2k = chr_regs_1k[bank_2k];
-			bank_2k &= chr_bank_mask;
-			addr = (bank_2k << 11) | ofs;
-			return VROM[addr];
+			if (addr < 0x2000)
+			{
+				int bank_1k = addr >> 10;
+				int ofs = addr & ((1 << 10) - 1);
+				bank_1k = chr_regs_1k[bank_1k];
+				bank_1k &= chr_bank_mask;
+				addr = (bank_1k << 10) | ofs;
+				return VROM[addr];
+			}
+			else return base.ReadPPU(addr);
 		}
 	}
 }
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