fceugx/source/fceultra/boards/183.cpp

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2009-07-17 19:27:04 +02:00
/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2005 CaH4e3
*
* 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
*
* Gimmick Bootleg (VRC4 mapper)
*/
#include "mapinc.h"
static uint8 prg[4];
static uint8 chr[8];
static uint8 IRQCount;
static uint8 IRQPre;
static uint8 IRQa;
static SFORMAT StateRegs[]=
{
{prg, 4, "PRG"},
{chr, 8, "CHR"},
{&IRQCount, 1, "IRQCOUNT"},
{&IRQPre, 1, "IRQPRE"},
{&IRQa, 1, "IRQA"},
{0}
};
static void SyncPrg(void)
{
setprg8(0x6000,0);
setprg8(0x8000,prg[0]);
setprg8(0xA000,prg[1]);
setprg8(0xC000,prg[2]);
setprg8(0xE000,~0);
}
static void SyncChr(void)
{
int i;
for(i=0; i<8; i++)
setchr1(i<<10,chr[i]);
}
static void StateRestore(int version)
{
SyncPrg();
SyncChr();
}
static DECLFW(M183Write)
{
if(((A&0xF80C)>=0xB000)&&((A&0xF80C)<=0xE00C))
{
uint8 index=(((A>>11)-6)|(A>>3))&7;
chr[index]=(chr[index]&(0xF0>>(A&4)))|((V&0x0F)<<(A&4));
SyncChr();
}
else switch (A&0xF80C)
{
case 0x8800: prg[0]=V; SyncPrg(); break;
case 0xA800: prg[1]=V; SyncPrg(); break;
case 0xA000: prg[2]=V; SyncPrg(); break;
case 0x9800: switch (V&3)
{
case 0: setmirror(MI_V); break;
case 1: setmirror(MI_H); break;
case 2: setmirror(MI_0); break;
case 3: setmirror(MI_1); break;
}
break;
case 0xF000: IRQCount=((IRQCount&0xF0)|(V&0xF)); break;
case 0xF004: IRQCount=((IRQCount&0x0F)|((V&0xF)<<4)); break;
case 0xF008: IRQa=V; if(!V)IRQPre=0; X6502_IRQEnd(FCEU_IQEXT); break;
case 0xF00C: IRQPre=16; break;
}
}
static void M183IRQCounter(void)
{
if(IRQa)
{
IRQCount++;
if((IRQCount-IRQPre)==238)
X6502_IRQBegin(FCEU_IQEXT);
}
}
static void M183Power(void)
{
IRQPre=IRQCount=IRQa=0;
SetReadHandler(0x8000,0xFFFF,CartBR);
SetWriteHandler(0x8000,0xFFFF,M183Write);
SetReadHandler(0x6000,0x7FFF,CartBR);
SyncPrg();
SyncChr();
}
void Mapper183_Init(CartInfo *info)
{
info->Power=M183Power;
GameHBIRQHook=M183IRQCounter;
GameStateRestore=StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}