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Viewing changes to fceu/src/mappers/21.cpp

  • Committer: Bazaar Package Importer
  • Author(s): Fabrice Coutadeur
  • Date: 2009-12-14 08:05:17 UTC
  • Revision ID: james.westby@ubuntu.com-20091214080517-abi5tj8avthfan7c
Tags: upstream-2.1.2+repack
Import upstream version 2.1.2+repack

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fceu/src/mappers/21.cpp
 
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/* FCE Ultra - NES/Famicom Emulator
 
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 *
 
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 * Copyright notice for this file:
 
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 *  Copyright (C) 2002 Xodnizel
 
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 *
 
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 * This program is free software; you can redistribute it and/or modify
 
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 * it under the terms of the GNU General Public License as published by
 
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 * the Free Software Foundation; either version 2 of the License, or
 
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 * (at your option) any later version.
 
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 *
 
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 * This program is distributed in the hope that it will be useful,
 
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 
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 * GNU General Public License for more details.
 
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 *
 
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 * You should have received a copy of the GNU General Public License
 
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 * along with this program; if not, write to the Free Software
 
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
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 */
 
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#include "mapinc.h"
 
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#define K4buf mapbyte2
 
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#define K4IRQ mapbyte1[1]
 
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#define K4sel mapbyte1[0]
 
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static int acount=0;
 
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DECLFW(Mapper21_write)
 
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{
 
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        A|=((A>>5)&0xF);
 
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        if((A&0xF000)==0xA000)
 
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          ROM_BANK8(0xA000,V);
 
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        else if((A&0xF000)==0x8000)
 
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        {
 
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         if(K4sel&2)
 
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          ROM_BANK8(0xC000,V);
 
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         else
 
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          ROM_BANK8(0x8000,V);
 
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         }
 
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        else if(A>=0xb000 && A<=0xefff)
 
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        {
 
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          A&=0xF006;
 
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          {
 
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           int x=((A>>2)&1)|((A-0xB000)>>11);
 
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           K4buf[x]&=(0xF0)>>((A&2)<<1);
 
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           K4buf[x]|=(V&0xF)<<((A&2)<<1);
 
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           VROM_BANK1(x<<10,K4buf[x]);
 
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          }
 
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        }
 
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        else switch(A&0xF006)
 
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        {
 
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         case 0x9000:
 
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                     switch(V&0x3)
 
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                     {
 
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                      case 0:MIRROR_SET(0);break;
 
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                      case 1:MIRROR_SET(1);break;
 
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                      case 2:onemir(0);break;
 
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                      case 3:onemir(1);break;
 
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                      }
 
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                     break;
 
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         case 0x9006:
 
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         case 0x9004:
 
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         case 0x9002:if((K4sel&2)!=(V&2))
 
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                     {
 
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                           uint8 swa;
 
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                      swa=PRGBankList[0];
 
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                       ROM_BANK8(0x8000,PRGBankList[2]);
 
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                      ROM_BANK8(0xc000,swa);
 
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                      }
 
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                     K4sel=V;
 
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                     break;
 
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         case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
 
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         case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
 
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         case 0xf004:IRQCount=IRQLatch;acount=0;
 
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                     IRQa=V&2;K4IRQ=V&1;
 
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                     X6502_IRQEnd(FCEU_IQEXT);
 
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                     break;
 
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         case 0xf006:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break;
 
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 }
 
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}
 
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static void KonamiIRQHook(int a)
 
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{
 
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  #define LCYCS ((227*2)+1)
 
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  //#define LCYCS 341
 
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  if(IRQa)
 
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  {
 
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//    acount+=a*3;
 
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    acount+=a*4;
 
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    if(acount>=LCYCS)
 
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    {
 
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     doagainbub:acount-=LCYCS;IRQCount++;
 
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     if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
 
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     if(acount>=LCYCS) goto doagainbub;
 
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    }
 
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 }
 
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}
 
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void Mapper21_init(void)
 
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{
 
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        SetWriteHandler(0x8000,0xffff,Mapper21_write);
 
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        MapIRQHook=KonamiIRQHook;
 
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}