mappers/83.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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20
  21 #include "mapinc.h"
  22
  23 static uint8 is2kbank, isnot2kbank, dipreg;
  24
  25 /*void Mapper83_init(void)
  26 {
  27
  28 }
  29 */
  30 static void m83IRQHook(int a)
  31 {
  32   if(IRQa)
  33   {
  34    IRQCount-=a;
  35    if(IRQCount<0)
  36    {
  37     X6502_IRQBegin(FCEU_IQEXT);
  38     IRQa=0;
  39     IRQCount=0xFFFF;
  40    }
  41   }
  42 }
  43
  44 static DECLFW(wrlow)
  45 {
  46  mapbyte4[A&3]=V;
  47 }
  48
  49 static DECLFR(rdlow)
  50 {
  51  return mapbyte4[A&3];
  52 }
  53
  54 static DECLFR(rd5000)
  55 {
  56  return dipreg;
  57 }
  58
  59 static void m83prg(void)
  60 {
  61   ROM_BANK16(0x8000,(mapbyte1[0]&0x3F));
  62   ROM_BANK16(0xC000,(mapbyte1[0]&0x30)|0xF);
  63 }
  64
  65 static void m83chr(void)
  66 {
  67   if(is2kbank&&!isnot2kbank)
  68   {
  69     VROM_BANK2(0x0000,mapbyte2[0]);
  70     VROM_BANK2(0x0800,mapbyte2[1]);
  71     VROM_BANK2(0x1000,mapbyte2[6]);
  72     VROM_BANK2(0x1800,mapbyte2[7]);
  73   }
  74   else
  75   {
  76     int x;
  77     for(x=0;x<8;x++)
  78        VROM_BANK1(x*0x400,mapbyte2[x]|((mapbyte1[0]&0x30)<<4));
  79   }
  80 }
  81
  82 static DECLFW(Mapper83_write)
  83 {
  84  //printf("$%04x:$%02x\n",A,V);
  85  switch(A)
  86  {
  87   case 0x8000: is2kbank = 1;
  88   case 0xB000:
  89   case 0xB0FF:
  90   case 0xB1FF:
  91        {
  92         mapbyte1[0]=V;
  93         m83prg();
  94         m83chr();
  95        }
  96        break;
  97   case 0x8100:
  98               mapbyte3[0]=V&0x80;
  99               switch(V&0x3)
 100               {
 101               case 0x00:MIRROR_SET2(1);break;
 102               case 0x01:MIRROR_SET2(0);break;
 103               case 0x02:onemir(0);break;
 104               case 0x03:onemir(1);break;
 105               }
 106               break;
 107   case 0x8200:IRQCount&=0xFF00;IRQCount|=V;X6502_IRQEnd(FCEU_IQEXT);break;
 108   case 0x8201:IRQa=mapbyte3[0];IRQCount&=0xFF;IRQCount|=V<<8;break;
 109   case 0x8300:ROM_BANK8(0x8000,V);break;
 110   case 0x8301:ROM_BANK8(0xA000,V);break;
 111   case 0x8302:ROM_BANK8(0xC000,V);break;
 112   case 0x8310:mapbyte2[0]=V;m83chr();break;
 113   case 0x8311:mapbyte2[1]=V;m83chr();break;
 114   case 0x8312:mapbyte2[2]=V;isnot2kbank = 1;m83chr();break; // 2 mappers in one :)
 115   case 0x8313:mapbyte2[3]=V;isnot2kbank = 1;m83chr();break;
 116   case 0x8314:mapbyte2[4]=V;isnot2kbank = 1;m83chr();break;
 117   case 0x8315:mapbyte2[5]=V;isnot2kbank = 1;m83chr();break;
 118   case 0x8316:mapbyte2[6]=V;m83chr();break;
 119   case 0x8317:mapbyte2[7]=V;m83chr();break;
 120   case 0x8318:mapbyte1[1]=V;m83prg();break;
 121  }
 122 // printf("$%04x:$%02x, $%04x\n",A,V,X.PC.W);
 123
 124 }
 125
 126 static void m83Reset(void)
 127 {
 128  dipreg^=1;
 129 }
 130
 131 void Mapper83_init(void)
 132 {
 133  is2kbank = 0;
 134  isnot2kbank = 0;
 135  dipreg = 0;
 136  ROM_BANK8(0xc000,0x1e);
 137  ROM_BANK8(0xe000,0x1f);
 138
 139  MapIRQHook=m83IRQHook;
 140  MapperReset=m83Reset;
 141
 142  SetReadHandler(0x5000,0x5000,rd5000); // title scren dip switch
 143  SetReadHandler(0x5100,0x5103,rdlow);
 144  SetWriteHandler(0x5100,0x5103,wrlow);
 145  SetWriteHandler(0x8000,0xffff,Mapper83_write);
 146  mapbyte1[1]=0xF;
 147 }