fceux/mappers/50.c

76 lines
1.6 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 void FP_FASTAPASS(1) Mapper50IRQ(int a)
{
if(IRQa)
{
if(IRQCount<4096)
IRQCount+=a;
else
{
IRQa=0;
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void M50Restore(int version)
{
setprg8(0xc000,mapbyte1[0]);
}
static DECLFW(M50W)
{
if((A&0xD060)==0x4020)
{
if(A&0x100)
{
IRQa=V&1;
if(!IRQa) IRQCount=0;
X6502_IRQEnd(FCEU_IQEXT);
}
else
{
V=((V&1)<<2)|((V&2)>>1)|((V&4)>>1)|(V&8);
mapbyte1[0]=V;
setprg8(0xc000,V);
}
}
}
void Mapper50_init(void)
{
SetWriteHandler(0x4020,0x5fff,M50W);
SetReadHandler(0x6000,0xffff,CartBR);
MapStateRestore=M50Restore;
MapIRQHook=Mapper50IRQ;
setprg8(0x6000,0xF);
setprg8(0x8000,0x8);
setprg8(0xa000,0x9);
setprg8(0xc000,0x0);
setprg8(0xe000,0xB);
}