| 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 19 | * (VRC4 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 | } |
| 41 | |
| 42 | A=(A&0xF003)|((A&0xC)>>2); |
| 43 | |
| 44 | if((A&0xF000)==0xA000) |
| 45 | ROM_BANK8(0xA000,V); |
| 46 | else if(A>=0xB000 && A<=0xEFFF) |
| 47 | { |
| 48 | int x=(A&1)|((A-0xB000)>>11); |
| 49 | |
| 50 | K4buf[x]&=(0xF0)>>((A&2)<<1); |
| 51 | K4buf[x]|=(V&0xF)<<((A&2)<<1); |
| 52 | if(weirdo) |
| 53 | weirdo--; |
| 54 | else |
| 55 | VROM_BANK1(x<<10,K4buf[x]); |
| 56 | } |
| 57 | else if((A&0xF000)==0x8000) |
| 58 | { |
| 59 | if(K4sel&2) |
| 60 | ROM_BANK8(0xC000,V); |
| 61 | else |
| 62 | ROM_BANK8(0x8000,V); |
| 63 | } |
| 64 | else switch(A) |
| 65 | { |
| 66 | case 0x9000:switch(V&0x3) |
| 67 | { |
| 68 | case 0:MIRROR_SET(0);break; |
| 69 | case 1:MIRROR_SET(1);break; |
| 70 | case 2:onemir(0);break; |
| 71 | case 3:onemir(1);break; |
| 72 | } |
| 73 | break; |
| 74 | case 0x9001:if((K4sel&2)!=(V&2)) |
| 75 | { |
| 76 | uint8 swa; |
| 77 | swa=PRGBankList[0]; |
| 78 | ROM_BANK8(0x8000,PRGBankList[2]); |
| 79 | ROM_BANK8(0xc000,swa); |
| 80 | } |
| 81 | K4sel=V; |
| 82 | break; |
| 83 | case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break; |
| 84 | case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break; |
| 85 | case 0xf001:IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;acount=0;X6502_IRQEnd(FCEU_IQEXT);break; |
| 86 | case 0xf003:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | static void FP_FASTAPASS(1) KonamiIRQHook(int a) |
| 91 | { |
| 92 | // #define LCYCS ((227*2)) |
| 93 | #define LCYCS 341 |
| 94 | if(IRQa) |
| 95 | { |
| 96 | acount+=a*3; |
| 97 | // acount+=a*4; |
| 98 | if(acount>=LCYCS) |
| 99 | { |
| 100 | doagainbub:acount-=LCYCS;IRQCount++; |
| 101 | if(IRQCount&0x100) |
| 102 | {//acount=0; |
| 103 | X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch; |
| 104 | } |
| 105 | if(acount>=LCYCS) goto doagainbub; |
| 106 | } |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | void Mapper25_init(void) |
| 111 | { |
| 112 | SetWriteHandler(0x8000,0xffff,Mapper25_write); |
| 113 | MapIRQHook=KonamiIRQHook; |
| 114 | } |
| 115 | |