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https://github.com/dborth/fceugx.git
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107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/* FCE Ultra - NES/Famicom Emulator
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*
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* Copyright notice for this file:
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* Copyright (C) 2002 Xodnizel
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include "mapinc.h"
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#define K4buf mapbyte2
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#define K4IRQ mapbyte1[1]
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#define K4sel mapbyte1[0]
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static int acount=0;
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DECLFW(Mapper21_write)
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{
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A|=((A>>5)&0xF);
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if((A&0xF000)==0xA000)
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ROM_BANK8(0xA000,V);
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else if((A&0xF000)==0x8000)
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{
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if(K4sel&2)
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ROM_BANK8(0xC000,V);
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else
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ROM_BANK8(0x8000,V);
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}
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else if(A>=0xb000 && A<=0xefff)
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{
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A&=0xF006;
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{
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int x=((A>>2)&1)|((A-0xB000)>>11);
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K4buf[x]&=(0xF0)>>((A&2)<<1);
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K4buf[x]|=(V&0xF)<<((A&2)<<1);
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VROM_BANK1(x<<10,K4buf[x]);
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}
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}
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else switch(A&0xF006)
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{
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case 0x9000:
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switch(V&0x3)
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{
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case 0:MIRROR_SET(0);break;
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case 1:MIRROR_SET(1);break;
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case 2:onemir(0);break;
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case 3:onemir(1);break;
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}
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break;
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case 0x9006:
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case 0x9004:
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case 0x9002:if((K4sel&2)!=(V&2))
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{
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uint8 swa;
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swa=PRGBankList[0];
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ROM_BANK8(0x8000,PRGBankList[2]);
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ROM_BANK8(0xc000,swa);
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}
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K4sel=V;
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break;
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case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
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case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
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case 0xf004:IRQCount=IRQLatch;acount=0;
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IRQa=V&2;K4IRQ=V&1;
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X6502_IRQEnd(FCEU_IQEXT);
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break;
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case 0xf006:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break;
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}
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}
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static void FP_FASTAPASS(1) KonamiIRQHook(int a)
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{
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#define LCYCS ((227*2)+1)
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//#define LCYCS 341
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if(IRQa)
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{
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// acount+=a*3;
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acount+=a*4;
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if(acount>=LCYCS)
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{
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doagainbub:acount-=LCYCS;IRQCount++;
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if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
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if(acount>=LCYCS) goto doagainbub;
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}
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}
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}
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void Mapper21_init(void)
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{
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SetWriteHandler(0x8000,0xffff,Mapper21_write);
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MapIRQHook=KonamiIRQHook;
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}
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