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1 | /* FCE Ultra - NES/Famicom Emulator |
2 | * |
3 | * Copyright notice for this file: |
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4 | * Copyright (C) 2002 Xodnizel |
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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 |
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18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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19 | */ |
20 | |
21 | #include "mapinc.h" |
22 | |
23 | |
24 | static DECLFW(Mapper42_write) |
25 | { |
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26 | // FCEU_printf("%04x:%04x\n",A,V); |
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27 | switch(A&0xe003) |
28 | { |
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29 | case 0x8000:VROM_BANK8(V);break; |
30 | case 0xe000:mapbyte1[0]=V;ROM_BANK8(0x6000,V&0xF);break; |
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31 | case 0xe001:MIRROR_SET((V>>3)&1);break; |
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32 | case 0xe002:IRQa=V&2;if(!IRQa) IRQCount=0;X6502_IRQEnd(FCEU_IQEXT);break; |
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33 | } |
34 | } |
35 | |
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36 | static void Mapper42IRQ(int a) |
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37 | { |
38 | if(IRQa) |
39 | { |
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40 | IRQCount+=a; |
41 | if(IRQCount>=32768) IRQCount-=32768; |
42 | if(IRQCount>=24576) |
43 | X6502_IRQBegin(FCEU_IQEXT); |
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44 | else |
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45 | X6502_IRQEnd(FCEU_IQEXT); |
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46 | } |
47 | } |
48 | |
49 | static void Mapper42_StateRestore(int version) |
50 | { |
51 | ROM_BANK8(0x6000,mapbyte1[0]&0xF); |
52 | } |
53 | |
54 | |
55 | void Mapper42_init(void) |
56 | { |
57 | ROM_BANK8(0x6000,0); |
58 | ROM_BANK32(~0); |
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59 | SetWriteHandler(0x6000,0xffff,Mapper42_write); |
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60 | SetReadHandler(0x6000,0x7fff,CartBR); |
61 | MapStateRestore=Mapper42_StateRestore; |
62 | MapIRQHook=Mapper42IRQ; |
63 | } |
64 | |