From 4f4805760be2dcd7a74367824d4b26d2e4c71f2d Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@users.sf.net>
Date: Sun, 15 Apr 2012 04:24:29 +0000
Subject: [PATCH] rewrite more of mapper 227 to work even better (fixes Xiang
 Shuai Chuan Qi better)

---
 src/mappers/227.cpp | 70 ++++++++++++++++++++++++++-------------------
 1 file changed, 41 insertions(+), 29 deletions(-)

diff --git a/src/mappers/227.cpp b/src/mappers/227.cpp
index 81da154a..9dd61621 100644
--- a/src/mappers/227.cpp
+++ b/src/mappers/227.cpp
@@ -20,51 +20,63 @@
 
 #include "mapinc.h"
 
+//zero 14-apr-2012 - redid this entirely to match bizhawk
+
 #define rg mapbyte1
 
 static void DoSync(uint32 A)
-{
- int32 p=((A>>3)&0xF) | ((A>>4)&0x10);
+{
+	int S = A & 1;
+	int M_horz = (A>>1)&1;
+	int p = (A >> 2) & 0x1F;
+	p += (A&0x100) ? 0x20 : 0;
+	bool o = (A>>7)&1;
+	bool L = (A>>9)&1;
+
+	if (o && !S )	
+	{
+		ROM_BANK16(0x8000,p);
+		ROM_BANK16(0xC000,p);
+	}
+	if (o && S )
+	{
+		ROM_BANK16(0x8000,p);
+		ROM_BANK16(0xC000,p+1);
+	}
+	if (!o && !S && !L )
+	{
+		ROM_BANK16(0x8000,p);
+		ROM_BANK16(0xC000,p&0x38);
+	}
+	if (!o && S && !L )
+	{
+		ROM_BANK16(0x8000,p&0x3E);
+		ROM_BANK16(0xC000,p&0x38);
+	}
+	if (!o && !S && L)
+	{
+		ROM_BANK16(0x8000,p);
+		ROM_BANK16(0xC000,p|7);
+	}
+	if (!o && S && L )
+	{
+		ROM_BANK16(0x8000,p&0x3E);
+		ROM_BANK16(0xC000,p|7);
+	}
 
  rg[0]=A;
  rg[1]=A>>8;
 
  MIRROR_SET((A>>1)&1);
- if(A&1)        //32 KB
- {
-  ROM_BANK32(p);
- }
- else                //16 KB
- {
-  ROM_BANK16(0x8000,(p<<1)|((A&4)>>2));
-  ROM_BANK16(0xc000,(p<<1)|((A&4)>>2));
- }
- if(A&0x80)
- {
-  //zero 09-apr-2012 - re #3515350
-  //removed this to fix [NJXXX] Xiang Shuai Chuan Qi which wouldnt be able to write any of its vram otherwise
-  //if this needs to be here for some other reason, then we'll have to learn how to decide when to do it
-  //PPUCHRRAM=0;
- }
- else
- {
-  PPUCHRRAM=0xFF;
-  if(A&0x200)
-   ROM_BANK16(0xC000,(p<<1)|7);
-  else
-   ROM_BANK16(0xC000,(p<<1)&(~7));
- }
 }
 
 static DECLFW(Mapper227_write)
 {
- rg[A&1]=V;
  DoSync(A);
 }
 
 static void M227Reset(void)
 {
- rg[0]=rg[1]=0;
  DoSync(0);
 }
 
@@ -75,7 +87,7 @@ static void M227Restore(int version)
 
 void Mapper227_init(void)
 {
-  SetWriteHandler(0x6000,0xffff,Mapper227_write);
+  SetWriteHandler(0x8000,0xffff,Mapper227_write);
   MapperReset=M227Reset;
   GameStateRestore=M227Restore;
   M227Reset();