mappers/83.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 void FP_FASTAPASS(1) m83IRQHook(int a)
  24 {
  25   if(IRQa)
  26   {
  27    IRQCount-=a;
  28    if(IRQCount<0)
  29    {
  30     TriggerIRQ();
  31     IRQa=0;
  32     IRQCount=0xFFFF;
  33    }
  34   }
  35 }
  36
  37 static DECLFW(wrlow)
  38 {
  39  mapbyte4[A&3]=V;
  40 }
  41
  42 static DECLFR(rdlow)
  43 {
  44  return mapbyte4[A&3];
  45 }
  46
  47 static void m83prg(void)
  48 {
  49   ROM_BANK16(0x8000,mapbyte1[0]&0x3F);
  50   ROM_BANK16(0xC000,(mapbyte1[0]&0x30)|0xF);
  51 }
  52
  53 static void m83chr(void)
  54 {
  55   int x;
  56   for(x=0;x<8;x++)
  57    VROM_BANK1(x*0x400,mapbyte2[x]|((mapbyte1[0]&0x30)<<4));
  58 }
  59
  60 static DECLFW(Mapper83_write)
  61 {
  62  //printf("$%04x:$%02x\n",A,V);
  63  switch(A)
  64  {
  65   case 0x8000:
  66   case 0xB000:
  67   case 0xB0FF:
  68   case 0xB1FF:
  69        {
  70         mapbyte1[0]=V;
  71         m83prg();
  72         m83chr();
  73        }
  74        break;
  75   case 0x8100:
  76               switch(V&0x3)
  77               {
  78               case 0x00:MIRROR_SET2(1);break;
  79               case 0x01:MIRROR_SET2(0);break;
  80               case 0x02:onemir(0);break;
  81               case 0x03:onemir(1);break;
  82               }
  83               break;
  84   case 0x8200:IRQCount&=0xFF00;IRQCount|=V;break;
  85   case 0x8201:IRQa=1;IRQCount&=0xFF;IRQCount|=V<<8;break;
  86   //case 0x8300:ROM_BANK8(0x8000,V);break;
  87   //case 0x8301:ROM_BANK8(0xA000,V);break;
  88   //case 0x8302:ROM_BANK8(0xC000,V);break;
  89   case 0x8310:mapbyte2[0]=V;m83chr();break;
  90   case 0x8311:mapbyte2[1]=V;m83chr();break;
  91   case 0x8312:mapbyte2[2]=V;m83chr();break;
  92   case 0x8313:mapbyte2[3]=V;m83chr();break;
  93   case 0x8314:mapbyte2[4]=V;m83chr();break;
  94   case 0x8315:mapbyte2[5]=V;m83chr();break;
  95   case 0x8316:mapbyte2[6]=V;m83chr();break;
  96   case 0x8317:mapbyte2[7]=V;m83chr();break;
  97  }
  98 // printf("$%04x:$%02x, $%04x\n",A,V,X.PC.W);
  99
 100 }
 101
 102 void Mapper83_init(void)
 103 {
 104
 105  ROM_BANK8(0xc000,0x1e);
 106  ROM_BANK8(0xe000,0x1f);
 107
 108  MapIRQHook=m83IRQHook;
 109
 110  SetReadHandler(0x5100,0x5103,rdlow);
 111  SetWriteHandler(0x5100,0x5103,wrlow);
 112  SetWriteHandler(0x8000,0xffff,Mapper83_write);
 113 }