c62d2810 |
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 | |
24 | static DECLFW(Mapper42_write) |
25 | { |
26 | switch(A&0xe003) |
27 | { |
28 | case 0xe000:mapbyte1[0]=V;ROM_BANK8(0x6000,V&0xF);break; |
29 | case 0xe001:MIRROR_SET((V>>3)&1);break; |
30 | case 0xe002:IRQa=V&2;if(!IRQa) IRQCount=0;break; |
31 | } |
32 | } |
33 | |
34 | static void FP_FASTAPASS(1) Mapper42IRQ(int a) |
35 | { |
36 | if(IRQa) |
37 | { |
38 | if(IRQCount<24576) |
39 | IRQCount+=a; |
40 | else |
41 | { |
42 | IRQa=0; |
43 | TriggerIRQ(); |
44 | } |
45 | } |
46 | } |
47 | |
48 | static void Mapper42_StateRestore(int version) |
49 | { |
50 | ROM_BANK8(0x6000,mapbyte1[0]&0xF); |
51 | } |
52 | |
53 | |
54 | void Mapper42_init(void) |
55 | { |
56 | ROM_BANK8(0x6000,0); |
57 | ROM_BANK32(~0); |
58 | SetWriteHandler(0xe000,0xffff,Mapper42_write); |
59 | SetReadHandler(0x6000,0x7fff,CartBR); |
60 | MapStateRestore=Mapper42_StateRestore; |
61 | MapIRQHook=Mapper42IRQ; |
62 | } |
63 | |