fceugx/source/fceultra/boards/ks7017.cpp

/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2007 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
 *
 * FDS Conversion
 *
 */

#include "mapinc.h"

static uint8 reg, mirr;
static int32 IRQa, IRQCount, IRQLatch;
static uint8 *WRAM = NULL;
static uint32 WRAMSIZE;

static SFORMAT StateRegs[] =
{
	{ &mirr, 1, "MIRR" },
	{ &reg, 1, "REGS" },
	{ &IRQa, 4, "IRQA" },
	{ &IRQCount, 4, "IRQC" },
	{ &IRQLatch, 4, "IRQL" },
	{ 0 }
};

static void Sync(void) {
	setprg16(0x8000, reg);
	setprg16(0xC000, 2);
	setmirror(mirr);
}

static DECLFW(UNLKS7017Write) {
//	FCEU_printf("bs %04x %02x\n",A,V);
	if ((A & 0xFF00) == 0x4A00) {
		reg = ((A >> 2) & 3) | ((A >> 4) & 4);
	} else if ((A & 0xFF00) == 0x5100) {
		Sync();
	} else if (A == 0x4020) {
		X6502_IRQEnd(FCEU_IQEXT);
		IRQCount &= 0xFF00;
		IRQCount |= V;
	} else if (A == 0x4021) {
		X6502_IRQEnd(FCEU_IQEXT);
		IRQCount &= 0xFF;
		IRQCount |= V << 8;
		IRQa = 1;
	} else if (A == 0x4025) {
		mirr = ((V & 8) >> 3) ^ 1;
	}
}
static DECLFR(FDSRead4030) {
	X6502_IRQEnd(FCEU_IQEXT);
	return X.IRQlow & FCEU_IQEXT ? 1 : 0;
}

static void UNL7017IRQ(int a) {
	if (IRQa) {
		IRQCount -= a;
		if (IRQCount <= 0) {
			IRQa = 0;
			X6502_IRQBegin(FCEU_IQEXT);
		}
	}
}

static void UNLKS7017Power(void) {
	Sync();
	setchr8(0);
	setprg8r(0x10, 0x6000, 0);
	SetReadHandler(0x6000, 0x7FFF, CartBR);
	SetWriteHandler(0x6000, 0x7FFF, CartBW);
	SetReadHandler(0x8000, 0xFFFF, CartBR);
	SetReadHandler(0x4030, 0x4030, FDSRead4030);
	SetWriteHandler(0x4020, 0x5FFF, UNLKS7017Write);
}

static void UNLKS7017Close(void) {
	if (WRAM)
		FCEU_gfree(WRAM);
	WRAM = NULL;
}

static void StateRestore(int version) {
	Sync();
}

void UNLKS7017_Init(CartInfo *info) {
	info->Power = UNLKS7017Power;
	info->Close = UNLKS7017Close;
	MapIRQHook = UNL7017IRQ;

	WRAMSIZE = 8192;
	WRAM = (uint8*)FCEU_gmalloc(WRAMSIZE);
	SetupCartPRGMapping(0x10, WRAM, WRAMSIZE, 1);
	AddExState(WRAM, WRAMSIZE, 0, "WRAM");

	GameStateRestore = StateRestore;
	AddExState(&StateRegs, ~0, 0, 0);
}