mappers/23.c

   1 /* FCE Ultra - NES/Famicom Emulator
   2  *
   3  * Copyright notice for this file:
   4  *  Copyright (C) 2002 Ben Parnell
   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 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   X6502_Rebase();
  36  }
  37   else if((A&0xF000)==0xA000)
  38   {
  39    ROM_BANK8(0xA000,V);
  40    X6502_Rebase();
  41   }
  42   else
  43   {
  44    A|=((A>>2)&0x3)|((A>>4)&0x3)|((A>>6)&0x3);
  45    A&=0xF003;
  46    if(A>=0xb000 && A<=0xe003)
  47    {
  48     int x=((A>>1)&1)|((A-0xB000)>>11);
  49
  50     K4buf[x]&=(0xF0)>>((A&1)<<2);
  51     K4buf[x]|=(V&0xF)<<((A&1)<<2);
  52     VROM_BANK1(x<<10,K4buf[x]);
  53    }
  54    else
  55     switch(A)
  56     {
  57      case 0xf000:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
  58      case 0xf001:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0x0F;IRQLatch|=V<<4;break;
  59      case 0xf002:X6502_IRQEnd(FCEU_IQEXT);IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;break;
  60      case 0xf003:X6502_IRQEnd(FCEU_IQEXT);IRQa=K4IRQ;break;
  61      case 0x9001:
  62      case 0x9002:
  63      case 0x9003:
  64                  if((K4sel&2)!=(V&2))
  65                  {
  66                   uint8 swa;
  67                   swa=PRGBankList[0];
  68                   ROM_BANK8(0x8000,PRGBankList[2]);
  69                   ROM_BANK8(0xc000,swa);
  70                   X6502_Rebase();
  71                  }
  72                  K4sel=V;
  73                  break;
  74      case 0x9000:
  75                 switch(V&0x3)
  76                 {
  77                  case 0:MIRROR_SET(0);break;
  78                  case 1:MIRROR_SET(1);break;
  79                  case 2:onemir(0);break;
  80                  case 3:onemir(1);break;
  81                 }
  82                 break;
  83   }
  84  }
  85 }
  86
  87 void FP_FASTAPASS(1) KonamiIRQHook2(int a)
  88 {
  89   static int acount=0;
  90   if(IRQa)
  91    {
  92     acount+=(a<<1)+a;
  93     if(acount>=342)
  94     {
  95      doagainbub:acount-=342;IRQCount++;
  96      if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
  97      if(acount>=342) goto doagainbub;
  98     }
  99  }
 100 }
 101
 102 void Mapper23_init(void)
 103 {
 104         SetWriteHandler(0x8000,0xffff,Mapper23_write);
 105         MapIRQHook=KonamiIRQHook2;
 106 }
 107