mappers/mmc2and4.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 MMC4reg mapbyte1
  24 #define latcha1 mapbyte2[0]
  25 #define latcha2 mapbyte2[1]
  26
  27
  28 static void FP_FASTAPASS(1) latchcheck(uint32 VAddr)
  29 {
  30      uint8 l,h;
  31
  32      h=VAddr>>8;
  33
  34      if(h>=0x20 || ((h&0xF)!=0xF))
  35       return;
  36
  37      l=VAddr&0xF0;
  38
  39      if(h<0x10)
  40      {
  41       if(l==0xD0)
  42       {
  43        VROM_BANK4(0x0000,MMC4reg[0]);
  44        latcha1=0xFD;
  45       }
  46       else if(l==0xE0)
  47       {
  48        VROM_BANK4(0x0000,MMC4reg[1]);
  49        latcha1=0xFE;
  50       }
  51      }
  52      else
  53      {
  54       if(l==0xD0)
  55       {
  56        VROM_BANK4(0x1000,MMC4reg[2]);
  57        latcha2=0xFD;
  58       }
  59       else if(l==0xE0)
  60       {
  61        VROM_BANK4(0x1000,MMC4reg[3]);
  62        latcha2=0xFE;
  63       }
  64      }
  65 }
  66
  67 DECLFW(Mapper9_write)   // $Axxx
  68 {
  69  ROM_BANK8(0x8000,V);
  70 }
  71
  72 DECLFW(Mapper10_write)
  73 {
  74  ROM_BANK16(0x8000,V);
  75 }
  76
  77 DECLFW(Mapper9and10_write)
  78 {
  79        switch(A&0xF000)
  80        {
  81         case 0xB000:
  82                 if (latcha1==0xFD) { VROM_BANK4(0x0000,V);}
  83                 MMC4reg[0]=V;
  84                 break;
  85         case 0xC000:
  86                 if (latcha1==0xFE) {VROM_BANK4(0x0000,V);}
  87                 MMC4reg[1]=V;
  88                 break;
  89         case 0xD000:
  90                 if (latcha2==0xFD) {VROM_BANK4(0x1000,V);}
  91                 MMC4reg[2]=V;
  92                 break;
  93         case 0xE000:
  94                 if (latcha2==0xFE) {VROM_BANK4(0x1000,V);}
  95                 MMC4reg[3]=V;
  96                 break;
  97         case 0xF000:
  98                 MIRROR_SET(V&1);
  99                 break;
 100         }
 101 }
 102
 103 void Mapper9_init(void)
 104 {
 105         latcha1=0xFE;
 106         latcha2=0xFE;
 107         ROM_BANK8(0xA000,~2);
 108         ROM_BANK8(0x8000,0);
 109         SetWriteHandler(0xA000,0xAFFF,Mapper9_write);
 110         SetWriteHandler(0xB000,0xFFFF,Mapper9and10_write);
 111         PPU_hook=latchcheck;
 112 }
 113
 114 void Mapper10_init(void)
 115 {
 116         latcha1=latcha2=0xFE;
 117         SetWriteHandler(0xA000,0xAFFF,Mapper10_write);
 118         SetWriteHandler(0xB000,0xFFFF,Mapper9and10_write);
 119         PPU_hook=latchcheck;
 120 }
 121