| 1 | /* FCE Ultra - NES/Famicom Emulator |
| 2 | * |
| 3 | * Copyright notice for this file: |
| 4 | * Copyright (C) 2005 CaH4e3 |
| 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 | |
| 22 | #include "mapinc.h" |
| 23 | |
| 24 | static uint16 IRQCount; |
| 25 | static uint8 IRQa; |
| 26 | static uint8 prg_reg[2]; |
| 27 | static uint8 chr_reg[8]; |
| 28 | |
| 29 | static SFORMAT StateRegs[]= |
| 30 | { |
| 31 | {&IRQCount, 2, "IRQC"}, |
| 32 | {&IRQa, 2, "IRQA"}, |
| 33 | {prg_reg, 2, "PRG"}, |
| 34 | {chr_reg, 8, "CHR"}, |
| 35 | {0} |
| 36 | }; |
| 37 | |
| 38 | static void M222IRQ(void) |
| 39 | { |
| 40 | if(IRQa) |
| 41 | { |
| 42 | IRQCount++; |
| 43 | if(IRQCount>=240) |
| 44 | { |
| 45 | X6502_IRQBegin(FCEU_IQEXT); |
| 46 | IRQa=0; |
| 47 | } |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | static void Sync(void) |
| 52 | { |
| 53 | setprg8(0x8000,prg_reg[0]); |
| 54 | setprg8(0xA000,prg_reg[1]); |
| 55 | int i; |
| 56 | for(i=0; i<8; i++) |
| 57 | setchr1(i<<10,chr_reg[i]); |
| 58 | } |
| 59 | |
| 60 | static DECLFW(M222Write) |
| 61 | { |
| 62 | switch(A&0xF003) |
| 63 | { |
| 64 | case 0x8000: prg_reg[0]=V; break; |
| 65 | case 0xA000: prg_reg[1]=V; break; |
| 66 | case 0xB000: chr_reg[0]=V; break; |
| 67 | case 0xB002: chr_reg[1]=V; break; |
| 68 | case 0xC000: chr_reg[2]=V; break; |
| 69 | case 0xC002: chr_reg[3]=V; break; |
| 70 | case 0xD000: chr_reg[4]=V; break; |
| 71 | case 0xD002: chr_reg[5]=V; break; |
| 72 | case 0xE000: chr_reg[6]=V; break; |
| 73 | case 0xE002: chr_reg[7]=V; break; |
| 74 | case 0xF000: IRQCount=IRQa=V; |
| 75 | X6502_IRQEnd(FCEU_IQEXT); |
| 76 | break; |
| 77 | } |
| 78 | Sync(); |
| 79 | } |
| 80 | |
| 81 | static void M222Power(void) |
| 82 | { |
| 83 | setprg16(0xC000,~0); |
| 84 | SetReadHandler(0x8000,0xFFFF,CartBR); |
| 85 | SetWriteHandler(0x8000,0xFFFF,M222Write); |
| 86 | } |
| 87 | |
| 88 | static void StateRestore(int version) |
| 89 | { |
| 90 | Sync(); |
| 91 | } |
| 92 | |
| 93 | void Mapper222_Init(CartInfo *info) |
| 94 | { |
| 95 | info->Power=M222Power; |
| 96 | GameHBIRQHook=M222IRQ; |
| 97 | GameStateRestore=StateRestore; |
| 98 | AddExState(&StateRegs, ~0, 0, 0); |
| 99 | } |