mappers/18.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 K4buf2 mapbyte3
  25
  26 void FP_FASTAPASS(1) JalecoIRQHook(int a)
  27 {
  28   if(IRQa && IRQCount)
  29   {
  30    IRQCount-=a;
  31    if(IRQCount<=0)
  32    {
  33     X6502_IRQBegin(FCEU_IQEXT);
  34     IRQCount=0;
  35     IRQa=0;
  36    }
  37   }
  38 }
  39
  40 DECLFW(Mapper18_write)
  41 {
  42         A&=0xF003;
  43         if(A>=0x8000 && A<=0x9001)
  44         {
  45          int x=((A>>1)&1)|((A-0x8000)>>11);
  46
  47          K4buf2[x]&=(0xF0)>>((A&1)<<2);
  48          K4buf2[x]|=(V&0xF)<<((A&1)<<2);
  49          ROM_BANK8(0x8000+(x<<13),K4buf2[x]);
  50         }
  51         else if(A>=0xa000 && A<=0xd003)
  52         {
  53          int x=((A>>1)&1)|((A-0xA000)>>11);
  54
  55          K4buf[x]&=(0xF0)>>((A&1)<<2);
  56          K4buf[x]|=(V&0xF)<<((A&1)<<2);
  57          VROM_BANK1(x<<10,K4buf[x]);
  58         }
  59         else switch(A)
  60         {
  61          case 0xe000:IRQLatch&=0xFFF0;IRQLatch|=(V&0x0f);break;
  62          case 0xe001:IRQLatch&=0xFF0F;IRQLatch|=(V&0x0f)<<4;break;
  63          case 0xe002:IRQLatch&=0xF0FF;IRQLatch|=(V&0x0f)<<8;break;
  64          case 0xe003:IRQLatch&=0x0FFF;IRQLatch|=(V&0x0f)<<12;break;
  65          case 0xf000:IRQCount=IRQLatch;
  66                      break;
  67          case 0xf001:IRQa=V&1;
  68                      X6502_IRQEnd(FCEU_IQEXT);
  69                      break;
  70          case 0xf002:MIRROR_SET2(V&1);
  71                      if(V&2) onemir(0);
  72                      break;
  73         }
  74 }
  75
  76 void Mapper18_init(void)
  77 {
  78  SetWriteHandler(0x8000,0xffff,Mapper18_write);
  79  MapIRQHook=JalecoIRQHook;
  80 }