| 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 | */ |
| 20 | |
| 21 | #include "mapinc.h" |
| 22 | |
| 23 | static uint8 prgreg[4], chrreg[8]; |
| 24 | static uint8 IRQa, IRQCount, IRQLatch; |
| 25 | |
| 26 | static SFORMAT StateRegs[]= |
| 27 | { |
| 28 | {&IRQa, 1, "IRQA"}, |
| 29 | {&IRQCount, 1, "IRQC"}, |
| 30 | {&IRQLatch, 1, "IRQL"}, |
| 31 | {prgreg, 4, "PREGS"}, |
| 32 | {chrreg, 8, "CREGS"}, |
| 33 | {0} |
| 34 | }; |
| 35 | |
| 36 | static void Sync(void) |
| 37 | { |
| 38 | setprg8(0x8000,prgreg[0]); |
| 39 | setprg8(0xa000,prgreg[1]); |
| 40 | setprg8(0xc000,prgreg[2]); |
| 41 | setprg8(0xe000,prgreg[3]); |
| 42 | int i; |
| 43 | for(i=0; i<8; i++) |
| 44 | setchr1(i<<10,chrreg[i]); |
| 45 | } |
| 46 | |
| 47 | static DECLFW(M117Write) |
| 48 | { |
| 49 | if(A<0x8004) |
| 50 | { |
| 51 | prgreg[A&3]=V; |
| 52 | Sync(); |
| 53 | } |
| 54 | else if((A>=0xA000)&&(A<=0xA007)) |
| 55 | { |
| 56 | chrreg[A&7]=V; |
| 57 | Sync(); |
| 58 | } |
| 59 | else switch(A) |
| 60 | { |
| 61 | case 0xc001: IRQLatch=V; break; |
| 62 | case 0xc003: IRQCount=IRQLatch; IRQa|=2; break; |
| 63 | case 0xe000: IRQa&=~1; IRQa|=V&1; X6502_IRQEnd(FCEU_IQEXT); break; |
| 64 | case 0xc002: X6502_IRQEnd(FCEU_IQEXT); break; |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | static void M117Power(void) |
| 69 | { |
| 70 | prgreg[0]=~3; prgreg[1]=~2; prgreg[2]=~1; prgreg[3]=~0; |
| 71 | Sync(); |
| 72 | SetReadHandler(0x8000,0xFFFF,CartBR); |
| 73 | SetWriteHandler(0x8000,0xFFFF,M117Write); |
| 74 | } |
| 75 | |
| 76 | static void M117IRQHook(void) |
| 77 | { |
| 78 | if(IRQa==3&&IRQCount) |
| 79 | { |
| 80 | IRQCount--; |
| 81 | if(!IRQCount) |
| 82 | { |
| 83 | IRQa&=1; |
| 84 | X6502_IRQBegin(FCEU_IQEXT); |
| 85 | } |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | static void StateRestore(int version) |
| 90 | { |
| 91 | Sync(); |
| 92 | } |
| 93 | |
| 94 | void Mapper117_Init(CartInfo *info) |
| 95 | { |
| 96 | info->Power=M117Power; |
| 97 | GameHBIRQHook=M117IRQHook; |
| 98 | GameStateRestore=StateRestore; |
| 99 | AddExState(&StateRegs, ~0, 0, 0); |
| 100 | } |
| 101 | |