| 1 | /* FCE Ultra - NES/Famicom Emulator\r |
| 2 | *\r |
| 3 | * Copyright notice for this file:\r |
| 4 | * Copyright (C) 2012 CaH4e3\r |
| 5 | *\r |
| 6 | * This program is free software; you can redistribute it and/or modify\r |
| 7 | * it under the terms of the GNU General Public License as published by\r |
| 8 | * the Free Software Foundation; either version 2 of the License, or\r |
| 9 | * (at your option) any later version.\r |
| 10 | *\r |
| 11 | * This program is distributed in the hope that it will be useful,\r |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of\r |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r |
| 14 | * GNU General Public License for more details.\r |
| 15 | *\r |
| 16 | * You should have received a copy of the GNU General Public License\r |
| 17 | * along with this program; if not, write to the Free Software\r |
| 18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA\r |
| 19 | */\r |
| 20 | \r |
| 21 | #include "mapinc.h"\r |
| 22 | \r |
| 23 | static uint8 preg[4], creg[8];\r |
| 24 | static uint8 IRQa, mirr;\r |
| 25 | static int32 IRQCount, IRQLatch;\r |
| 26 | \r |
| 27 | static SFORMAT StateRegs[]=\r |
| 28 | {\r |
| 29 | {preg, 4, "PREG"},\r |
| 30 | {creg, 8, "CREG"},\r |
| 31 | {&mirr, 1, "MIRR"},\r |
| 32 | {&IRQa, 1, "IRQA"},\r |
| 33 | {&IRQCount, 4, "IRQC"},\r |
| 34 | {&IRQLatch, 4, "IRQL"},\r |
| 35 | {0}\r |
| 36 | };\r |
| 37 | \r |
| 38 | static void Sync(void)\r |
| 39 | {\r |
| 40 | int i;\r |
| 41 | for(i=0; i<8; i++) setchr1(i<<10,creg[i]);\r |
| 42 | setprg8(0x8000,preg[0]);\r |
| 43 | setprg8(0xA000,preg[1]);\r |
| 44 | setprg8(0xC000,preg[2]);\r |
| 45 | setprg8(0xE000,~0);\r |
| 46 | if(mirr & 2)\r |
| 47 | setmirror(MI_0);\r |
| 48 | else\r |
| 49 | setmirror(mirr & 1);\r |
| 50 | }\r |
| 51 | \r |
| 52 | static DECLFW(M18WriteIRQ)\r |
| 53 | {\r |
| 54 | switch(A & 0xF003) {\r |
| 55 | case 0xE000: IRQLatch&=0xFFF0; IRQLatch|=(V&0x0f)<<0x0;break;\r |
| 56 | case 0xE001: IRQLatch&=0xFF0F; IRQLatch|=(V&0x0f)<<0x4; break;\r |
| 57 | case 0xE002: IRQLatch&=0xF0FF; IRQLatch|=(V&0x0f)<<0x8; break;\r |
| 58 | case 0xE003: IRQLatch&=0x0FFF; IRQLatch|=(V&0x0f)<<0xC; break;\r |
| 59 | case 0xF000: IRQCount=IRQLatch; break;\r |
| 60 | case 0xF001: IRQa=V&1; X6502_IRQEnd(FCEU_IQEXT); break;\r |
| 61 | case 0xF002: mirr = V&3; Sync(); break;\r |
| 62 | }\r |
| 63 | }\r |
| 64 | \r |
| 65 | static DECLFW(M18WritePrg)\r |
| 66 | {\r |
| 67 | uint32 i = ((A >> 1) & 1)|((A - 0x8000) >> 11);\r |
| 68 | preg[i] &= (0xF0) >> ((A & 1) << 2);\r |
| 69 | preg[i] |= (V & 0xF) << ((A & 1) << 2);\r |
| 70 | Sync();\r |
| 71 | }\r |
| 72 | \r |
| 73 | static DECLFW(M18WriteChr)\r |
| 74 | {\r |
| 75 | uint32 i = ((A >> 1) & 1)|((A - 0xA000) >> 11);\r |
| 76 | creg[i] &= (0xF0) >> ((A & 1) << 2);\r |
| 77 | creg[i] |= (V & 0xF) << ((A & 1) << 2);\r |
| 78 | Sync();\r |
| 79 | }\r |
| 80 | \r |
| 81 | static void M18Power(void)\r |
| 82 | {\r |
| 83 | preg[0] = 0;\r |
| 84 | preg[1] = 1;\r |
| 85 | preg[2] = ~1;\r |
| 86 | preg[3] = ~0;\r |
| 87 | Sync();\r |
| 88 | SetReadHandler(0x8000,0xFFFF,CartBR);\r |
| 89 | SetWriteHandler(0x8000,0x9FFF,M18WritePrg);\r |
| 90 | SetWriteHandler(0xA000,0xDFFF,M18WriteChr);\r |
| 91 | SetWriteHandler(0xE000,0xFFFF,M18WriteIRQ);\r |
| 92 | }\r |
| 93 | \r |
| 94 | static void FP_FASTAPASS(1) M18IRQHook(int a)\r |
| 95 | {\r |
| 96 | if(IRQa && IRQCount)\r |
| 97 | {\r |
| 98 | IRQCount-=a;\r |
| 99 | if(IRQCount<=0)\r |
| 100 | {\r |
| 101 | X6502_IRQBegin(FCEU_IQEXT);\r |
| 102 | IRQCount=0;\r |
| 103 | IRQa=0;\r |
| 104 | }\r |
| 105 | }\r |
| 106 | }\r |
| 107 | \r |
| 108 | static void StateRestore(int version)\r |
| 109 | {\r |
| 110 | Sync();\r |
| 111 | }\r |
| 112 | \r |
| 113 | void Mapper18_Init(CartInfo *info)\r |
| 114 | {\r |
| 115 | info->Power=M18Power;\r |
| 116 | MapIRQHook=M18IRQHook;\r |
| 117 | GameStateRestore=StateRestore;\r |
| 118 | \r |
| 119 | AddExState(&StateRegs, ~0, 0, 0);\r |
| 120 | }\r |
| 121 | \r |