frameskip, cleanups
[fceu.git] / mappers / 23.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(Mapper23_write)
28{
29 if((A&0xF000)==0x8000)
30 {
31 if(K4sel&2)
32 ROM_BANK8(0xC000,V);
33 else
34 ROM_BANK8(0x8000,V);
35 }
36 else if((A&0xF000)==0xA000)
37 ROM_BANK8(0xA000,V);
38 else
39 {
40 A|=((A>>2)&0x3)|((A>>4)&0x3)|((A>>6)&0x3);
41 A&=0xF003;
42 if(A>=0xb000 && A<=0xe003)
43 {
44 int x=((A>>1)&1)|((A-0xB000)>>11);
45
46 K4buf[x]&=(0xF0)>>((A&1)<<2);
47 K4buf[x]|=(V&0xF)<<((A&1)<<2);
48 VROM_BANK1(x<<10,K4buf[x]);
49 }
50 else
51 switch(A)
52 {
53 case 0xf000:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
54 case 0xf001:X6502_IRQEnd(FCEU_IQEXT);IRQLatch&=0x0F;IRQLatch|=V<<4;break;
55 case 0xf002:X6502_IRQEnd(FCEU_IQEXT);IRQCount=IRQLatch;IRQa=V&2;K4IRQ=V&1;break;
56 case 0xf003:X6502_IRQEnd(FCEU_IQEXT);IRQa=K4IRQ;break;
57 case 0x9001:
58 case 0x9002:
59 case 0x9003:
60 if((K4sel&2)!=(V&2))
61 {
62 uint8 swa;
63 swa=PRGBankList[0];
64 ROM_BANK8(0x8000,PRGBankList[2]);
65 ROM_BANK8(0xc000,swa);
66 }
67 K4sel=V;
68 break;
69 case 0x9000:
70 switch(V&0x3)
71 {
72 case 0:MIRROR_SET(0);break;
73 case 1:MIRROR_SET(1);break;
74 case 2:onemir(0);break;
75 case 3:onemir(1);break;
76 }
77 break;
78 }
79 }
80}
81
82void FP_FASTAPASS(1) KonamiIRQHook2(int a)
83{
84 static int acount=0;
85 if(IRQa)
86 {
87 acount+=(a<<1)+a;
88 if(acount>=342)
89 {
90 doagainbub:acount-=342;IRQCount++;
91 if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
92 if(acount>=342) goto doagainbub;
93 }
94 }
95}
96
97void Mapper23_init(void)
98{
99 SetWriteHandler(0x8000,0xffff,Mapper23_write);
100 MapIRQHook=KonamiIRQHook2;
101}
102