mappers/25.c

   1 /* FCE Ultra - NES/Famicom Emulator
   2  *
   3  * Copyright notice for this file:
   4  *  Copyright (C) 2002 Xodnizel
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "mapinc.h"
  22
  23 #define K4buf mapbyte2
  24 #define K4IRQ mapbyte1[1]
  25 #define K4sel mapbyte1[0]
  26
  27 static int acount=0;
  28 static DECLFW(Mapper25_write)
  29 {
  30         A=(A&0xF003)|((A&0xC)>>2);
  31
  32         if((A&0xF000)==0xA000)
  33           ROM_BANK8(0xA000,V);
  34         else if(A>=0xB000 && A<=0xEFFF)
  35         {
  36          int x=(A&1)|((A-0xB000)>>11);
  37
  38          K4buf[x]&=(0xF0)>>((A&2)<<1);
  39          K4buf[x]|=(V&0xF)<<((A&2)<<1);
  40          VROM_BANK1(x<<10,K4buf[x]);
  41         }
  42         else if((A&0xF000)==0x8000)
  43         {
  44          if(K4sel&2)
  45           ROM_BANK8(0xC000,V);
  46          else
  47           ROM_BANK8(0x8000,V);
  48         }
  49         else switch(A)
  50         {
  51          case 0x9000:switch(V&0x3)
  52                      {
  53                       case 0:MIRROR_SET(0);break;
  54                       case 1:MIRROR_SET(1);break;
  55                       case 2:onemir(0);break;
  56                       case 3:onemir(1);break;
  57                       }
  58                      break;
  59          case 0x9001:if((K4sel&2)!=(V&2))
  60                      {
  61                            uint8 swa;
  62                       swa=PRGBankList[0];
  63                        ROM_BANK8(0x8000,PRGBankList[2]);
  64                       ROM_BANK8(0xc000,swa);
  65                      }
  66                      K4sel=V;
  67                      break;
  68         case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
  69         case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
  70         case 0xf001:IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;acount=0;X6502_IRQEnd(FCEU_IQEXT);break;
  71         case 0xf003:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break;
  72  }
  73 }
  74
  75 static void FP_FASTAPASS(1) KonamiIRQHook(int a)
  76 {
  77 //  #define LCYCS ((227*2))
  78   #define LCYCS 341
  79   if(IRQa)
  80   {
  81    acount+=a*3;
  82   // acount+=a*4;
  83    if(acount>=LCYCS)
  84    {
  85     doagainbub:acount-=LCYCS;IRQCount++;
  86     if(IRQCount&0x100)
  87     {//acount=0;
  88      X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;
  89         }
  90     if(acount>=LCYCS) goto doagainbub;
  91    }
  92  }
  93 }
  94
  95 void Mapper25_init(void)
  96 {
  97         SetWriteHandler(0x8000,0xffff,Mapper25_write);
  98         MapIRQHook=KonamiIRQHook;
  99 }
 100