From 62057f60cb3f7f0dde2fe75e7c3616b8d65156eb Mon Sep 17 00:00:00 2001
From: alyosha-tas <alexei.f.k@gmail.com>
Date: Sun, 23 Oct 2016 20:48:51 -0400
Subject: [PATCH] Add files via upload

---
 .../Nintendo/NES/Boards/MMC3_family/MMC3.cs   | 31 ++++++++++++-------
 1 file changed, 19 insertions(+), 12 deletions(-)

diff --git a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
index c83c17fd24..f0dcabb7e7 100644
--- a/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
+++ b/BizHawk.Emulation.Cores/Consoles/Nintendo/NES/Boards/MMC3_family/MMC3.cs
@@ -291,22 +291,29 @@ namespace BizHawk.Emulation.Cores.Nintendo.NES
 
 		public virtual void AddressPPU(int addr)
 		{
-			int a12 = (addr >> 12) & 1;
-			bool rising_edge = (a12 == 1 && a12_old == 0);
-			if (rising_edge)
+			// see https://forums.nesdev.com/viewtopic.php?f=3&t=11361&start=60
+			// apparently mmc3 can't see internal pattern tables
+			// fixes Recca
+			if (addr<0x3F00)
 			{
-				if (separator_counter > 0)
+				int a12 = (addr >> 12) & 1;
+				bool rising_edge = (a12 == 1 && a12_old == 0);
+				if (rising_edge)
 				{
-					separator_counter = 15;
+					if (separator_counter > 0)
+					{
+						separator_counter = 15;
+					}
+					else
+					{
+						separator_counter = 15;
+						irq_countdown = 6;
+					}
 				}
-				else
-				{
-					separator_counter = 15;
-					irq_countdown = 6;
-				}
-			}
 
-			a12_old = a12;
+				a12_old = a12;
+			}
+			
 		}
 	}