mappers/23.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 static int acount=0;
  27 static DECLFW(Mapper23_write)
  28 {
  29  if((A&0xF000)==0x8000)
  30  {
  31   if(K4sel&2)
  32    ROM_BANK8(0xC000,V);
  33   else
  34    ROM_BANK8(0x8000,V);
  35   }
  36   else if((A&0xF000)==0xA000)
  37    ROM_BANK8(0xA000,V);
  38   else
  39   {
  40    A|=((A>>2)&0x3)|((A>>4)&0x3)|((A>>6)&0x3);
  41    A&=0xF003;
  42    if(A>=0xb000 && A<=0xe003)
  43    {
  44     int x=((A>>1)&1)|((A-0xB000)>>11);
  45
  46     K4buf[x]&=(0xF0)>>((A&1)<<2);
  47     K4buf[x]|=(V&0xF)<<((A&1)<<2);
  48     VROM_BANK1(x<<10,K4buf[x]);
  49    }
  50    else
  51     switch(A)
  52     {
  53      case 0xf000:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
  54      case 0xf001:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0x0F;IRQLatch|=V<<4;break;
  55      case 0xf002:X6502_IRQEnd(FCEU_IQEXT);acount=0;IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;break;
  56      case 0xf003:X6502_IRQEnd(FCEU_IQEXT);IRQa=K4IRQ;break;
  57      case 0x9001:
  58      case 0x9002:
  59      case 0x9003:
  60                  if((K4sel&2)!=(V&2))
  61                  {
  62                   uint8 swa;
  63                   swa=PRGBankList[0];
  64                   ROM_BANK8(0x8000,PRGBankList[2]);
  65                   ROM_BANK8(0xc000,swa);
  66                  }
  67                  K4sel=V;
  68                  break;
  69      case 0x9000:
  70             if(V!=0xFF)
  71                      switch(V&0x3)
  72                 {
  73                  case 0:MIRROR_SET(0);break;
  74                       case 1:MIRROR_SET(1);break;
  75                      case 2:onemir(0);break;
  76                      case 3:onemir(1);break;
  77                 }
  78                 break;
  79   }
  80  }
  81 }
  82
  83 void FP_FASTAPASS(1) KonamiIRQHook2(int a)
  84 {
  85   #define LCYCS 341
  86   if(IRQa)
  87   {
  88    acount+=a*3;
  89     if(acount>=LCYCS)
  90     {
  91      doagainbub:acount-=LCYCS;IRQCount++;
  92      if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
  93      if(acount>=LCYCS) goto doagainbub;
  94     }
  95  }
  96 }
  97
  98 void Mapper23_init(void)
  99 {
 100         SetWriteHandler(0x8000,0xffff,Mapper23_write);
 101         MapIRQHook=KonamiIRQHook2;
 102 }
 103