fceux/mappers/42.cpp

65 lines
1.7 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"
static DECLFW(Mapper42_write)
{
// FCEU_printf("%04x:%04x\n",A,V);
switch(A&0xe003)
{
case 0x8000:VROM_BANK8(V);break;
case 0xe000:mapbyte1[0]=V;ROM_BANK8(0x6000,V&0xF);break;
case 0xe001:MIRROR_SET((V>>3)&1);break;
case 0xe002:IRQa=V&2;if(!IRQa) IRQCount=0;X6502_IRQEnd(FCEU_IQEXT);break;
}
}
static void FP_FASTAPASS(1) Mapper42IRQ(int a)
{
if(IRQa)
{
IRQCount+=a;
if(IRQCount>=32768) IRQCount-=32768;
if(IRQCount>=24576)
X6502_IRQBegin(FCEU_IQEXT);
else
X6502_IRQEnd(FCEU_IQEXT);
}
}
static void Mapper42_StateRestore(int version)
{
ROM_BANK8(0x6000,mapbyte1[0]&0xF);
}
void Mapper42_init(void)
{
ROM_BANK8(0x6000,0);
ROM_BANK32(~0);
SetWriteHandler(0x6000,0xffff,Mapper42_write);
SetReadHandler(0x6000,0x7fff,CartBR);
MapStateRestore=Mapper42_StateRestore;
MapIRQHook=Mapper42IRQ;
}