mappers/33.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 static DECLFW(Mapper33_write)
  24 {
  25         A&=0xF003;
  26
  27         //printf("$%04x:$%02x, %d\n",A,V,scanline);
  28         if(A>=0xA000 && A<=0xA003)
  29          VROM_BANK1(0x1000+((A&3)<<10),V);
  30         else switch(A){
  31         case 0x8000:if(!mapbyte1[0])
  32                      MIRROR_SET((V>>6)&1);
  33                     ROM_BANK8(0x8000,V);
  34                     X6502_Rebase();
  35                     break;
  36         case 0x8001:ROM_BANK8(0xA000,V);
  37                     X6502_Rebase();break;
  38         case 0x8002:VROM_BANK2(0x0000,V);break;
  39         case 0x8003:VROM_BANK2(0x0800,V);break;
  40         case 0xc000:IRQLatch=V;break;
  41         case 0xc001:IRQCount=IRQLatch;break;
  42         case 0xc003:IRQa=0;break;
  43         case 0xc002:IRQa=1;break;
  44         case 0xe000:mapbyte1[0]=1;MIRROR_SET((V>>6)&1);break;
  45         }
  46 }
  47
  48 static void heho(void)
  49 {
  50  if(IRQa)
  51  {
  52    IRQCount++;
  53    if(IRQCount==0x100)
  54    {
  55     TriggerIRQ();
  56     IRQa=0;
  57    }
  58  }
  59 }
  60
  61 void Mapper33_init(void)
  62 {
  63         SetWriteHandler(0x8000,0xffff,Mapper33_write);
  64         GameHBIRQHook=heho;
  65 }