/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2006 CaH4e3
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

//ccording to nestopia, BTL_SMB2_C, otherwise known as UNL-SMB2J

#include "mapinc.h"

static uint8 reg;
static uint8 IRQa;
static uint32 IRQCount;

static SFORMAT StateRegs[]=
{
  {&IRQCount, 4, "IRQC"},
  {&IRQa, 1, "IRQA"},
  {&reg, 1, "REG"},
  {0}
};

static void Sync(void)
{
  setprg4(0x5000,16);  
  setprg8(0x6000,2);
  setprg8(0x8000,1);
  setprg8(0xa000,0);
  setprg8(0xc000,reg);
  setprg8(0xe000,9);
  setchr8(0);
}

static DECLFW(M43Write)
{
  int transo[8]={4,3,4,4,4,7,5,6};
  switch(A&0xf1ff)
  {
    case 0x4022: reg=transo[V&7]; Sync(); break;
    case 0x8122: IRQa=V&1; IRQCount=0; break;
  }
}

static void M43Power(void)
{
  reg=0;
  Sync();
//  SetReadHandler(0x5000,0x5fff,CartBR);
  SetReadHandler(0x5000,0xffff,CartBR);
  SetWriteHandler(0x4020,0xffff,M43Write);
}

static void M43Reset(void)
{
}

static void M43IRQHook(int a)
{
 IRQCount+=a;
 if(IRQa)
  if(IRQCount>=4096)
  {
   IRQa=0;
   X6502_IRQBegin(FCEU_IQEXT);
  }
}

static void StateRestore(int version)
{
  Sync();
}

void Mapper43_Init(CartInfo *info)
{
  info->Reset=M43Reset;
  info->Power=M43Power;
  MapIRQHook=M43IRQHook;
  GameStateRestore=StateRestore;
  AddExState(&StateRegs, ~0, 0, 0);
}