merge mapper code from FCEUX
[fceu.git] / mappers / 25.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  * (VRCII mapper)
20  */
21
22 #include "mapinc.h"
23
24 #define K4buf mapbyte2
25 #define K4IRQ mapbyte1[1]
26 #define K4sel mapbyte1[0]
27
28 static int acount=0;
29 static int weirdo=0;
30 static DECLFW(Mapper25_write)
31 {
32         if(A==0xC007)
33                 {
34                         weirdo=8; // Ganbare Goemon Gaiden does strange things!!! at the end credits
35                               // quick dirty hack, seems there is no other games with such PCB, so
36                               // we never know if it will not work for something else lol
37                         VROM_BANK1(0x0000,0xFC);
38                         VROM_BANK1(0x0400,0xFD);
39                         VROM_BANK1(0x0800,0xFF);
40                         VROM_BANK1(0x0c00,0xCF);
41                 }
42
43                 A=(A&0xF003)|((A&0xC)>>2);
44
45         if((A&0xF000)==0xA000)
46           ROM_BANK8(0xA000,V);
47         else if(A>=0xB000 && A<=0xEFFF)
48         {
49          int x=(A&1)|((A-0xB000)>>11);
50
51          K4buf[x]&=(0xF0)>>((A&2)<<1);
52          K4buf[x]|=(V&0xF)<<((A&2)<<1);
53                  if(weirdo)
54                         weirdo--;
55                  else
56                         VROM_BANK1(x<<10,K4buf[x]);
57         }
58         else if((A&0xF000)==0x8000)
59         {
60          if(K4sel&2)
61           ROM_BANK8(0xC000,V);
62          else
63           ROM_BANK8(0x8000,V);
64         }
65         else switch(A)
66         {
67          case 0x9000:switch(V&0x3)
68                      {
69                       case 0:MIRROR_SET(0);break;
70                       case 1:MIRROR_SET(1);break;
71                       case 2:onemir(0);break;
72                       case 3:onemir(1);break;
73                       }
74                      break;
75          case 0x9001:if((K4sel&2)!=(V&2))
76                      {
77                            uint8 swa;
78                       swa=PRGBankList[0];
79                        ROM_BANK8(0x8000,PRGBankList[2]);
80                       ROM_BANK8(0xc000,swa);
81                      }
82                      K4sel=V;
83                      break;
84         case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
85         case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
86         case 0xf001:IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;acount=0;X6502_IRQEnd(FCEU_IQEXT);break;
87         case 0xf003:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break;
88  }
89 }
90
91 static void KonamiIRQHook(int a)
92 {
93 //  #define LCYCS ((227*2))
94   #define LCYCS 341
95   if(IRQa)
96   {
97    acount+=a*3;
98   // acount+=a*4;
99    if(acount>=LCYCS)
100    {
101     doagainbub:acount-=LCYCS;IRQCount++;
102     if(IRQCount&0x100)
103     {//acount=0;
104      X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;
105         }
106     if(acount>=LCYCS) goto doagainbub;
107    }
108  }
109 }
110
111 void Mapper25_init(void)
112 {
113         SetWriteHandler(0x8000,0xffff,Mapper25_write);
114         MapIRQHook=KonamiIRQHook;
115 }
116