| 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 mode mapbyte1[0] |
| 24 | #define page mapbyte1[1] |
| 25 | |
| 26 | static uint32 Get8K(uint32 A) |
| 27 | { |
| 28 | uint32 bank; |
| 29 | |
| 30 | bank=(page<<2)|((A>>13)&1); |
| 31 | |
| 32 | if(A&0x4000 && !(mode&1)) bank|=0xC; |
| 33 | if(!(A&0x8000)) bank|=0x20; |
| 34 | if(mode==2) bank|=2; |
| 35 | else bank|=(A>>13)&2; |
| 36 | return(bank); |
| 37 | } |
| 38 | |
| 39 | static void Synco(void) |
| 40 | { |
| 41 | uint32 x; |
| 42 | if(mapbyte1[0]<=2) |
| 43 | MIRROR_SET2(1); |
| 44 | else |
| 45 | MIRROR_SET2(0); |
| 46 | for(x=0x6000;x<0x10000;x+=8192) |
| 47 | ROM_BANK8(x,Get8K(x)); |
| 48 | } |
| 49 | |
| 50 | static DECLFW(Write) |
| 51 | { |
| 52 | if(A&0x8000) mapbyte1[1]=V&0xF; |
| 53 | else mapbyte1[0]=(mapbyte1[0]&2)|((V>>1)&1); |
| 54 | |
| 55 | if(A&0x4000) mapbyte1[0]=(mapbyte1[0]&1)|((V>>3)&2); |
| 56 | Synco(); |
| 57 | } |
| 58 | |
| 59 | void Mapper51_init(void) |
| 60 | { |
| 61 | SetWriteHandler(0x6000,0xFFFF,Write); |
| 62 | SetReadHandler(0x6000,0xFFFF,CartBR); |
| 63 | mapbyte1[0]=1; |
| 64 | mapbyte1[1]=0; |
| 65 | Synco(); |
| 66 | } |