merge mapper code from FCEUX

[fceu.git] / boards / 95.c

/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "mapinc.h"
#include "../ines.h"

static uint8 lastA;
static uint8 DRegs[8];
static uint8 cmd;
static uint8 MirCache[8];

static SFORMAT DB_StateRegs[]={
  {DRegs, 8, "DREG"},
  {&cmd, 1, "CMD"},
  {&lastA, 1, "LAST"},
  {0}
};

static void toot(void)
{
  int x;

  MirCache[0]=MirCache[1]=(DRegs[0]>>4)&1;
  MirCache[2]=MirCache[3]=(DRegs[1]>>4)&1;

  for(x=0;x<4;x++)
     MirCache[4+x]=(DRegs[2+x]>>5)&1;
  onemir(MirCache[lastA]);
}

static void Sync()
{
  setchr2(0x0000,DRegs[0]&0x1F);
  setchr2(0x0800,DRegs[1]&0x1F);
  setchr1(0x1000,DRegs[2]&0x1F);
  setchr1(0x1400,DRegs[3]&0x1F);
  setchr1(0x1800,DRegs[4]&0x1F);
  setchr1(0x1C00,DRegs[5]&0x1F);
  setprg8(0x8000,DRegs[6]&0x1F);
  setprg8(0xa000,DRegs[7]&0x1F);
  toot();
}

static DECLFW(Mapper95_write)
{
  switch(A&0xF001)
  {
    case 0x8000: cmd = V; break;
    case 0x8001:
     switch(cmd&0x07)
     {
       case 0: DRegs[0]=(V&0x3F)>>1; break;
       case 1: DRegs[1]=(V&0x3F)>>1; break;
       case 2: DRegs[2]=V&0x3F; break;
       case 3: DRegs[3]=V&0x3F; break;
       case 4: DRegs[4]=V&0x3F; break;
       case 5: DRegs[5]=V&0x3F; break;
       case 6: DRegs[6]=V&0x3F; break;
       case 7: DRegs[7]=V&0x3F; break;
     }
     Sync();
  }
}

static void dragonbust_ppu(uint32 A)
{
  static int last=-1;
  static uint8 z;

  if(A>=0x2000) return;

  A>>=10;
  lastA=A;
  z=MirCache[A];
  if(z!=last)
  {
    onemir(z);
    last=z;
  }
}

static void DBPower(void)
{
  memset(DRegs,0x3F,8);
  DRegs[0]=DRegs[1]=0x1F;

  Sync();

  setprg8(0xc000,0x3E);
  setprg8(0xe000,0x3F);

  SetReadHandler(0x8000,0xffff,CartBR);
  SetWriteHandler(0x8000,0xffff,Mapper95_write);
}

static void StateRestore(int version)
{
  Sync();
}

void Mapper95_Init(CartInfo *info)
{
  info->Power=DBPower;
  AddExState(DB_StateRegs, ~0, 0, 0);
  PPU_hook=dragonbust_ppu;
  GameStateRestore=StateRestore;
}