fceugx/source/fceultra/boards/91.cpp

96 lines
2.2 KiB
C++
Raw Normal View History

2012-12-14 18:18:20 +01:00
/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2012 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "mapinc.h"
static uint8 cregs[4], pregs[2];
static uint8 IRQCount, IRQa;
static SFORMAT StateRegs[]=
{
{cregs, 4, "CREG"},
{pregs, 2, "PREG"},
{&IRQa, 1, "IRQA"},
{&IRQCount, 1, "IRQC"},
{0}
};
static void Sync(void)
{
setprg8(0x8000,pregs[0]);
setprg8(0xa000,pregs[1]);
setprg8(0xc000,~1);
setprg8(0xe000,~0);
setchr2(0x0000,cregs[0]);
setchr2(0x0800,cregs[1]);
setchr2(0x1000,cregs[2]);
setchr2(0x1800,cregs[3]);
}
static DECLFW(M91Write0)
{
cregs[A & 3] = V;
Sync();
}
static DECLFW(M91Write1)
{
switch (A & 3)
{
case 0:
case 1: pregs[A & 1] = V; Sync(); break;
case 2: IRQa = IRQCount = 0; X6502_IRQEnd(FCEU_IQEXT); break;
case 3: IRQa = 1; X6502_IRQEnd(FCEU_IQEXT); break;
}
}
static void M91Power(void)
{
Sync();
SetWriteHandler(0x6000,0x6fff,M91Write0);
SetWriteHandler(0x7000,0x7fff,M91Write1);
SetReadHandler(0x8000,0xffff,CartBR);
}
static void M91IRQHook(void)
{
if(IRQCount<8 && IRQa)
{
IRQCount++;
if(IRQCount>=8)
{
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void StateRestore(int version)
{
Sync();
}
void Mapper91_Init(CartInfo *info)
{
info->Power=M91Power;
GameHBIRQHook=M91IRQHook;
GameStateRestore=StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}