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1 | /* FCE Ultra - NES/Famicom Emulator |
2 | * |
3 | * Copyright notice for this file: |
4 | * Copyright (C) 2002 Ben Parnell |
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 | #define K4buf mapbyte2 |
24 | #define K4IRQ mapbyte1[1] |
25 | #define K4sel mapbyte1[0] |
26 | |
27 | static int acount=0; |
28 | |
29 | DECLFW(Mapper21_write) |
30 | { |
31 | A|=((A>>5)&0xF); |
32 | |
33 | if((A&0xF000)==0xA000) |
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34 | { |
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35 | ROM_BANK8(0xA000,V); |
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36 | X6502_Rebase(); |
37 | } |
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38 | else if((A&0xF000)==0x8000) |
39 | { |
40 | if(K4sel&2) |
41 | ROM_BANK8(0xC000,V); |
42 | else |
43 | ROM_BANK8(0x8000,V); |
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44 | X6502_Rebase(); |
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45 | } |
46 | else if(A>=0xb000 && A<=0xefff) |
47 | { |
48 | A&=0xF006; |
49 | { |
50 | int x=((A>>2)&1)|((A-0xB000)>>11); |
51 | |
52 | K4buf[x]&=(0xF0)>>((A&2)<<1); |
53 | K4buf[x]|=(V&0xF)<<((A&2)<<1); |
54 | VROM_BANK1(x<<10,K4buf[x]); |
55 | } |
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56 | |
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57 | } |
58 | else switch(A&0xF006) |
59 | { |
60 | case 0x9000: |
61 | switch(V&0x3) |
62 | { |
63 | case 0:MIRROR_SET(0);break; |
64 | case 1:MIRROR_SET(1);break; |
65 | case 2:onemir(0);break; |
66 | case 3:onemir(1);break; |
67 | } |
68 | break; |
69 | case 0x9006: |
70 | case 0x9004: |
71 | case 0x9002:if((K4sel&2)!=(V&2)) |
72 | { |
73 | uint8 swa; |
74 | swa=PRGBankList[0]; |
75 | ROM_BANK8(0x8000,PRGBankList[2]); |
76 | ROM_BANK8(0xc000,swa); |
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77 | X6502_Rebase(); |
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78 | } |
79 | K4sel=V; |
80 | break; |
81 | case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break; |
82 | case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break; |
83 | case 0xf004:IRQCount=IRQLatch; |
84 | IRQa=V&2;K4IRQ=V&1;break; |
85 | case 0xf006:IRQa=K4IRQ;break; |
86 | } |
87 | } |
88 | static void FP_FASTAPASS(1) KonamiIRQHook(int a) |
89 | { |
90 | #define LCYCS 114 |
91 | if(IRQa) |
92 | { |
93 | acount+=a; |
94 | if(acount>=LCYCS) |
95 | { |
96 | doagainbub:acount-=LCYCS;IRQCount++; |
97 | if(IRQCount&0x100) {TriggerIRQ();IRQCount=IRQLatch;} |
98 | if(acount>=LCYCS) goto doagainbub; |
99 | } |
100 | } |
101 | } |
102 | |
103 | void Mapper21_init(void) |
104 | { |
105 | SetWriteHandler(0x8000,0xffff,Mapper21_write); |
106 | MapIRQHook=KonamiIRQHook; |
107 | } |