mappers/95.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 static uint8 lastA;
  24 static uint8 DRegs[8];
  25 static uint8 cmd;
  26 static uint8 MirCache[8];
  27
  28 static SFORMAT DB_StateRegs[]={
  29         {DRegs, 8, "DREG"},
  30         {&cmd, 1, "CMD"},
  31         {&lastA, 1, "LAST"},
  32         {0}
  33 };
  34
  35 static void FP_FASTAPASS(1) dragonbust_ppu(uint32 A)
  36 {
  37  static int last=-1;
  38  static uint8 z;
  39
  40  if(A>=0x2000) return;
  41
  42  A>>=10;
  43
  44  lastA=A;
  45
  46  z=MirCache[A];
  47  if(z!=last)
  48  {
  49   onemir(z);
  50   last=z;
  51  }
  52 }
  53
  54 static void toot(void)
  55 {
  56  int x;
  57
  58  MirCache[0]=MirCache[1]=(DRegs[0]>>4)&1;
  59  MirCache[2]=MirCache[3]=(DRegs[1]>>4)&1;
  60
  61  for(x=0;x<4;x++)
  62   MirCache[4+x]=(DRegs[2+x]>>5)&1;
  63  onemir(MirCache[lastA]);
  64 }
  65
  66 static DECLFW(Mapper95_write)
  67 {
  68         switch(A&0xF001)
  69         {
  70
  71          case 0x8000:
  72          cmd = V;
  73          break;
  74
  75          case 0x8001:
  76                 switch(cmd&0x07)
  77                 {
  78                  case 0: DRegs[0]=(V&0x3F)>>1;toot();V>>=1;setchr2(0x0000,V&0x1F);break;
  79                  case 1: DRegs[1]=(V&0x3F)>>1;toot();V>>=1;setchr2(0x0800,V&0x1F);break;
  80                  case 2: DRegs[2]=V&0x3F;toot();setchr1(0x1000,V&0x1F); break;
  81                  case 3: DRegs[3]=V&0x3F;toot();setchr1(0x1400,V&0x1F); break;
  82                  case 4: DRegs[4]=V&0x3F;toot();setchr1(0x1800,V&0x1F); break;
  83                  case 5: DRegs[5]=V&0x3F;toot();setchr1(0x1C00,V&0x1F); break;
  84                  case 6: DRegs[6]=V&0x3F;
  85                          setprg8(0x8000,V);
  86                          break;
  87                  case 7: DRegs[7]=V&0x3F;
  88                          setprg8(0xA000,V);
  89                          break;
  90                 }
  91                 break;
  92         }
  93 }
  94
  95 static void DBSync()
  96 {
  97  int x;
  98
  99  setchr2(0x0000,DRegs[0]);
 100  setchr2(0x0800,DRegs[1]);
 101
 102  for(x=0;x<4;x++)
 103   setchr1(0x1000+x*0x400,DRegs[2+x]);
 104
 105  setprg8(0x8000,DRegs[6]);
 106  setprg8(0xa000,DRegs[7]);
 107  toot();
 108 }
 109
 110 static void DBPower(void)
 111 {
 112  memset(DRegs,0x3F,8);
 113  DRegs[0]=DRegs[1]=0x1F;
 114
 115  DBSync();
 116
 117  setprg8(0xc000,0x3E);
 118  setprg8(0xe000,0x3F);
 119
 120  SetReadHandler(0x8000,0xffff,CartBR);
 121  SetWriteHandler(0x8000,0xffff,Mapper95_write);
 122 }
 123
 124 static void StateRestore(int version)
 125 {
 126  DBSync();
 127 }
 128
 129 void Mapper95_Init(CartInfo *info)
 130 {
 131   info->Power=DBPower;
 132   AddExState(DB_StateRegs, ~0, 0, 0);
 133   PPU_hook=dragonbust_ppu;
 134   GameStateRestore=StateRestore;
 135 }
 136