fceugx/source/fceultra/mappers/248.c
2008-09-02 01:55:12 +00:00

91 lines
2.2 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 cmd mapbyte1[0]
#define lpa mapbyte1[1]
#define prgl mapbyte2
static void PRGSynco(void)
{
if(lpa&0x80)
{
ROM_BANK16(0x8000,lpa&0xF);
}
else
{
ROM_BANK8(0x8000,prgl[0]&0x1F);
ROM_BANK8(0xa000,prgl[1]&0x1F);
}
}
static DECLFW(Mapper248_writelow)
{
lpa=V;
PRGSynco();
}
static DECLFW(Mapper248_write)
{
switch(A&0xF001)
{
case 0xa000:MIRROR_SET(V&1);break; // Not sure if this is right. Mirroring may be hard wired...
case 0xc000:IRQLatch=V;break;
case 0xc001:IRQCount=IRQLatch;break;
case 0xe000:IRQa=0;X6502_IRQEnd(FCEU_IQEXT);break;
case 0xe001:IRQa=1;break;
case 0x8000:cmd=V;break;
case 0x8001:switch(cmd&7)
{
case 0:VROM_BANK2(0x000,V>>1);break;
case 1:VROM_BANK2(0x800,V>>1);break;
case 2:VROM_BANK1(0x1000,V);break;
case 3:VROM_BANK1(0x1400,V);break;
case 4:VROM_BANK1(0x1800,V);break;
case 5:VROM_BANK1(0x1c00,V);break;
case 6:prgl[0]=V;PRGSynco();break;
case 7:prgl[1]=V;PRGSynco();break;
}
break;
}
}
static void Mapper248_hb(void)
{
if(IRQa)
{
IRQCount--;
if(IRQCount<0)
{
X6502_IRQBegin(FCEU_IQEXT);
IRQCount=IRQLatch;
}
}
}
void Mapper248_init(void)
{
SetWriteHandler(0x6000,0x6fff,Mapper248_writelow);
SetWriteHandler(0x8000,0xffff,Mapper248_write);
GameHBIRQHook=Mapper248_hb;
}