gpfce patch part3
[fceu.git] / mappers / 25.c
CommitLineData
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#define K4buf mapbyte2
24#define K4IRQ mapbyte1[1]
25#define K4sel mapbyte1[0]
26
27DECLFW(Mapper25_write)
28{
29 A=(A&0xF003)|((A&0xC)>>2);
30
31 if((A&0xF000)==0xA000)
32 ROM_BANK8(0xA000,V);
33 else if(A>=0xB000 && A<=0xEFFF)
34 {
35 int x=(A&1)|((A-0xB000)>>11);
36
37 K4buf[x]&=(0xF0)>>((A&2)<<1);
38 K4buf[x]|=(V&0xF)<<((A&2)<<1);
39 VROM_BANK1(x<<10,K4buf[x]);
40 }
41 else if((A&0xF000)==0x8000)
42 {
43 if(K4sel&2)
44 ROM_BANK8(0xC000,V);
45 else
46 ROM_BANK8(0x8000,V);
47 }
48 else switch(A)
49 {
50 case 0x9000:switch(V&0x3)
51 {
52 case 0:MIRROR_SET(0);break;
53 case 1:MIRROR_SET(1);break;
54 case 2:onemir(0);break;
55 case 3:onemir(1);break;
56 }
57 break;
58 case 0x9001:if((K4sel&2)!=(V&2))
59 {
60 uint8 swa;
61 swa=PRGBankList[0];
62 ROM_BANK8(0x8000,PRGBankList[2]);
63 ROM_BANK8(0xc000,swa);
64 }
65 K4sel=V;
66 break;
67 case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
68 case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
69 case 0xf001:IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;break;
70 case 0xf003:IRQa=K4IRQ;break;
71 }
72}
73
74static void FP_FASTAPASS(1) KonamiIRQHook(int a)
75{
76 static int count=0;
77 #define LCYCS 114
78 if(IRQa)
79 {
80 count+=a;
81 if(count>=LCYCS)
82 {
83 doagainbub:count-=LCYCS;IRQCount++;
84 if(IRQCount&0x100) {count=0;TriggerIRQ();IRQCount=IRQLatch;}
85 if(count>=LCYCS) goto doagainbub;
86 }
87 }
88}
89
90void Mapper25_init(void)
91{
92 SetWriteHandler(0x8000,0xffff,Mapper25_write);
93 MapIRQHook=KonamiIRQHook;
94}
95