| 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 cmd mapbyte1[0] |
| 24 | #define lpa mapbyte1[1] |
| 25 | #define prgl mapbyte2 |
| 26 | |
| 27 | static void PRGSynco(void) |
| 28 | { |
| 29 | if(lpa&0x80) |
| 30 | { |
| 31 | ROM_BANK16(0x8000,lpa&0xF); |
| 32 | } |
| 33 | else |
| 34 | { |
| 35 | ROM_BANK8(0x8000,prgl[0]&0x1F); |
| 36 | ROM_BANK8(0xa000,prgl[1]&0x1F); |
| 37 | } |
| 38 | X6502_Rebase(); |
| 39 | } |
| 40 | |
| 41 | static DECLFW(Mapper248_writelow) |
| 42 | { |
| 43 | lpa=V; |
| 44 | PRGSynco(); |
| 45 | } |
| 46 | |
| 47 | static DECLFW(Mapper248_write) |
| 48 | { |
| 49 | switch(A&0xF001) |
| 50 | { |
| 51 | case 0xa000:MIRROR_SET(V&1);break; // Not sure if this is right. Mirroring may be hard wired... |
| 52 | case 0xc000:IRQLatch=V;break; |
| 53 | case 0xc001:IRQCount=IRQLatch;break; |
| 54 | case 0xe000:IRQa=0;X6502_IRQEnd(FCEU_IQEXT);break; |
| 55 | case 0xe001:IRQa=1;break; |
| 56 | case 0x8000:cmd=V;break; |
| 57 | case 0x8001:switch(cmd&7) |
| 58 | { |
| 59 | case 0:VROM_BANK2(0x000,V>>1);break; |
| 60 | case 1:VROM_BANK2(0x800,V>>1);break; |
| 61 | case 2:VROM_BANK1(0x1000,V);break; |
| 62 | case 3:VROM_BANK1(0x1400,V);break; |
| 63 | case 4:VROM_BANK1(0x1800,V);break; |
| 64 | case 5:VROM_BANK1(0x1c00,V);break; |
| 65 | case 6:prgl[0]=V;PRGSynco();break; |
| 66 | case 7:prgl[1]=V;PRGSynco();break; |
| 67 | } |
| 68 | break; |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | static void Mapper248_hb(void) |
| 73 | { |
| 74 | if(IRQa) |
| 75 | { |
| 76 | IRQCount--; |
| 77 | if(IRQCount<0) |
| 78 | { |
| 79 | X6502_IRQBegin(FCEU_IQEXT); |
| 80 | IRQCount=IRQLatch; |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | void Mapper248_init(void) |
| 86 | { |
| 87 | SetWriteHandler(0x6000,0x6fff,Mapper248_writelow); |
| 88 | SetWriteHandler(0x8000,0xffff,Mapper248_write); |
| 89 | GameHBIRQHook=Mapper248_hb; |
| 90 | } |
| 91 | |