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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 |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
19 | */ |
20 | |
21 | #include "mapinc.h" |
22 | |
23 | |
24 | |
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25 | static DECLFW(Mapper73_write) |
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26 | { |
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27 | //if(A>=0xd000 && A<=0xdfff) |
28 | X6502_IRQEnd(FCEU_IQEXT); /* How are IRQs acknowledged on this chip? */ |
29 | switch(A&0xF000) |
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30 | { |
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31 | //default: printf("$%04x:$%02x\n",A,V);break; |
32 | case 0x8000:IRQCount&=0xFFF0;IRQCount|=(V&0xF);break; |
33 | case 0x9000:IRQCount&=0xFF0F;IRQCount|=(V&0xF)<<4;break; |
34 | case 0xa000:IRQCount&=0xF0FF;IRQCount|=(V&0xF)<<8;break; |
35 | case 0xb000:IRQCount&=0x0FFF;IRQCount|=(V&0xF)<<12;break; |
36 | case 0xc000:IRQa=V&2;break; |
37 | case 0xf000:ROM_BANK16(0x8000,V);break; |
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38 | } |
39 | } |
40 | |
41 | static void FP_FASTAPASS(1) Mapper73IRQHook(int a) |
42 | { |
43 | if(IRQa) |
44 | { |
45 | IRQCount+=a; |
46 | if(IRQCount>=0xFFFF) |
47 | { |
48 | IRQCount&=0xFFFF; |
49 | IRQa=0; |
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50 | X6502_IRQBegin(FCEU_IQEXT); |
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51 | } |
52 | } |
53 | } |
54 | |
55 | void Mapper73_init(void) |
56 | { |
57 | SetWriteHandler(0x8000,0xffff,Mapper73_write); |
58 | MapIRQHook=Mapper73IRQHook; |
59 | } |
60 | |