mirror of
https://github.com/dborth/fceugx.git
synced 2024-11-01 15:05:05 +01:00
107 lines
3.0 KiB
C++
107 lines
3.0 KiB
C++
/* FCE Ultra - NES/Famicom Emulator
|
|
*
|
|
* Copyright notice for this file:
|
|
* Copyright (C) 2002 Xodnizel
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include "mapinc.h"
|
|
|
|
#define K4buf mapbyte2
|
|
#define K4IRQ mapbyte1[1]
|
|
#define K4sel mapbyte1[0]
|
|
|
|
static int acount=0;
|
|
|
|
DECLFW(Mapper21_write)
|
|
{
|
|
A|=((A>>5)&0xF);
|
|
|
|
if((A&0xF000)==0xA000)
|
|
ROM_BANK8(0xA000,V);
|
|
else if((A&0xF000)==0x8000)
|
|
{
|
|
if(K4sel&2)
|
|
ROM_BANK8(0xC000,V);
|
|
else
|
|
ROM_BANK8(0x8000,V);
|
|
}
|
|
else if(A>=0xb000 && A<=0xefff)
|
|
{
|
|
A&=0xF006;
|
|
{
|
|
int x=((A>>2)&1)|((A-0xB000)>>11);
|
|
|
|
K4buf[x]&=(0xF0)>>((A&2)<<1);
|
|
K4buf[x]|=(V&0xF)<<((A&2)<<1);
|
|
VROM_BANK1(x<<10,K4buf[x]);
|
|
}
|
|
|
|
}
|
|
else switch(A&0xF006)
|
|
{
|
|
case 0x9000:
|
|
switch(V&0x3)
|
|
{
|
|
case 0:MIRROR_SET(0);break;
|
|
case 1:MIRROR_SET(1);break;
|
|
case 2:onemir(0);break;
|
|
case 3:onemir(1);break;
|
|
}
|
|
break;
|
|
case 0x9006:
|
|
case 0x9004:
|
|
case 0x9002:if((K4sel&2)!=(V&2))
|
|
{
|
|
uint8 swa;
|
|
swa=PRGBankList[0];
|
|
ROM_BANK8(0x8000,PRGBankList[2]);
|
|
ROM_BANK8(0xc000,swa);
|
|
}
|
|
K4sel=V;
|
|
break;
|
|
case 0xf000:IRQLatch&=0xF0;IRQLatch|=V&0xF;break;
|
|
case 0xf002:IRQLatch&=0x0F;IRQLatch|=V<<4;break;
|
|
case 0xf004:IRQCount=IRQLatch;acount=0;
|
|
IRQa=V&2;K4IRQ=V&1;
|
|
X6502_IRQEnd(FCEU_IQEXT);
|
|
break;
|
|
case 0xf006:IRQa=K4IRQ;X6502_IRQEnd(FCEU_IQEXT);break;
|
|
}
|
|
}
|
|
static void KonamiIRQHook(int a)
|
|
{
|
|
#define LCYCS ((227*2)+1)
|
|
//#define LCYCS 341
|
|
if(IRQa)
|
|
{
|
|
// acount+=a*3;
|
|
acount+=a*4;
|
|
if(acount>=LCYCS)
|
|
{
|
|
doagainbub:acount-=LCYCS;IRQCount++;
|
|
if(IRQCount&0x100) {X6502_IRQBegin(FCEU_IQEXT);IRQCount=IRQLatch;}
|
|
if(acount>=LCYCS) goto doagainbub;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Mapper21_init(void)
|
|
{
|
|
SetWriteHandler(0x8000,0xffff,Mapper21_write);
|
|
MapIRQHook=KonamiIRQHook;
|
|
}
|