| 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 rg mapbyte1 |
| 24 | |
| 25 | static void DoSync(uint32 A) |
| 26 | { |
| 27 | int32 p=((A>>3)&0xF) | ((A>>4)&0x10); |
| 28 | |
| 29 | rg[0]=A; |
| 30 | rg[1]=A>>8; |
| 31 | |
| 32 | MIRROR_SET((A>>1)&1); |
| 33 | if(A&1) //32 KB |
| 34 | { |
| 35 | ROM_BANK32(p); |
| 36 | } |
| 37 | else //16 KB |
| 38 | { |
| 39 | ROM_BANK16(0x8000,(p<<1)|((A&4)>>2)); |
| 40 | ROM_BANK16(0xc000,(p<<1)|((A&4)>>2)); |
| 41 | } |
| 42 | if(A&0x80) |
| 43 | { |
| 44 | PPUCHRRAM=0; |
| 45 | } |
| 46 | else |
| 47 | { |
| 48 | PPUCHRRAM=0xFF; |
| 49 | if(A&0x200) |
| 50 | ROM_BANK16(0xC000,(p<<1)|7); |
| 51 | else |
| 52 | ROM_BANK16(0xC000,(p<<1)&(~7)); |
| 53 | } |
| 54 | } |
| 55 | |
| 56 | static DECLFW(Mapper227_write) |
| 57 | { |
| 58 | rg[A&1]=V; |
| 59 | DoSync(A); |
| 60 | } |
| 61 | |
| 62 | static void M227Reset(void) |
| 63 | { |
| 64 | rg[0]=rg[1]=0; |
| 65 | DoSync(0); |
| 66 | } |
| 67 | |
| 68 | static void M227Restore(int version) |
| 69 | { |
| 70 | DoSync(rg[0]|(rg[1]<<8)); |
| 71 | } |
| 72 | |
| 73 | void Mapper227_init(void) |
| 74 | { |
| 75 | SetWriteHandler(0x8000,0xffff,Mapper227_write); |
| 76 | MapperReset=M227Reset; |
| 77 | GameStateRestore=M227Restore; |
| 78 | M227Reset(); |
| 79 | } |