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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 cmd mapbyte1[0] |
24 | #define lpa mapbyte1[1] |
25 | #define prgl mapbyte2 |
26 | |
27 | static void PRGSynco(void) |
28 | { |
29 | if(lpa&0x80) |
30 | { |
31 | ROM_BANK16(0x8000,lpa&0xF); |
32 | } |
33 | else |
34 | { |
35 | ROM_BANK8(0x8000,prgl[0]&0x1F); |
36 | ROM_BANK8(0xa000,prgl[1]&0x1F); |
37 | } |
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38 | X6502_Rebase(); |
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39 | } |
40 | |
41 | static DECLFW(Mapper248_writelow) |
42 | { |
43 | lpa=V; |
44 | PRGSynco(); |
45 | } |
46 | |
47 | static DECLFW(Mapper248_write) |
48 | { |
49 | switch(A&0xF001) |
50 | { |
51 | case 0xa000:MIRROR_SET(V&1);break; // Not sure if this is right. Mirroring may be hard wired... |
52 | case 0xc000:IRQLatch=V;break; |
53 | case 0xc001:IRQCount=IRQLatch;break; |
54 | case 0xe000:IRQa=0;X6502_IRQEnd(FCEU_IQEXT);break; |
55 | case 0xe001:IRQa=1;break; |
56 | case 0x8000:cmd=V;break; |
57 | case 0x8001:switch(cmd&7) |
58 | { |
59 | case 0:VROM_BANK2(0x000,V>>1);break; |
60 | case 1:VROM_BANK2(0x800,V>>1);break; |
61 | case 2:VROM_BANK1(0x1000,V);break; |
62 | case 3:VROM_BANK1(0x1400,V);break; |
63 | case 4:VROM_BANK1(0x1800,V);break; |
64 | case 5:VROM_BANK1(0x1c00,V);break; |
65 | case 6:prgl[0]=V;PRGSynco();break; |
66 | case 7:prgl[1]=V;PRGSynco();break; |
67 | } |
68 | break; |
69 | } |
70 | } |
71 | |
72 | static void Mapper248_hb(void) |
73 | { |
74 | if(IRQa) |
75 | { |
76 | IRQCount--; |
77 | if(IRQCount<0) |
78 | { |
79 | X6502_IRQBegin(FCEU_IQEXT); |
80 | IRQCount=IRQLatch; |
81 | } |
82 | } |
83 | } |
84 | |
85 | void Mapper248_init(void) |
86 | { |
87 | SetWriteHandler(0x6000,0x6fff,Mapper248_writelow); |
88 | SetWriteHandler(0x8000,0xffff,Mapper248_write); |
89 | GameHBIRQHook=Mapper248_hb; |
90 | } |
91 | |