fceux/boards/117.cpp

102 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"
static uint8 prgreg[4], chrreg[8];
static uint8 IRQa, IRQCount, IRQLatch;
static SFORMAT StateRegs[]=
{
{&IRQa, 1, "IRQA"},
{&IRQCount, 1, "IRQC"},
{&IRQLatch, 1, "IRQL"},
{prgreg, 4, "PREGS"},
{chrreg, 8, "CREGS"},
{0}
};
static void Sync(void)
{
int i;
setprg8(0x8000,prgreg[0]);
setprg8(0xa000,prgreg[1]);
setprg8(0xc000,prgreg[2]);
setprg8(0xe000,prgreg[3]);
for(i=0; i<8; i++)
setchr1(i<<10,chrreg[i]);
}
static DECLFW(M117Write)
{
if(A<0x8004)
{
prgreg[A&3]=V;
Sync();
}
else if((A>=0xA000)&&(A<=0xA007))
{
chrreg[A&7]=V;
Sync();
}
else switch(A)
{
case 0xc001: IRQLatch=V; break;
case 0xc003: IRQCount=IRQLatch; IRQa|=2; break;
case 0xe000: IRQa&=~1; IRQa|=V&1; X6502_IRQEnd(FCEU_IQEXT); break;
case 0xc002: X6502_IRQEnd(FCEU_IQEXT); break;
}
}
static void M117Power(void)
{
prgreg[0]=~3; prgreg[1]=~2; prgreg[2]=~1; prgreg[3]=~0;
Sync();
SetReadHandler(0x8000,0xFFFF,CartBR);
SetWriteHandler(0x8000,0xFFFF,M117Write);
}
static void M117IRQHook(void)
{
if(IRQa==3&&IRQCount)
{
IRQCount--;
if(!IRQCount)
{
IRQa&=1;
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void StateRestore(int version)
{
Sync();
}
void Mapper117_Init(CartInfo *info)
{
info->Power=M117Power;
GameHBIRQHook=M117IRQHook;
GameStateRestore=StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}