fceugx/source/fceultra/boards/33.cpp

/* 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 is48;
static uint8 regs[8], mirr;
static uint8 IRQa;
static int16 IRQCount, IRQLatch;

static SFORMAT StateRegs[] =
{
	{ regs, 8, "PREG" },
	{ &mirr, 1, "MIRR" },
	{ &IRQa, 1, "IRQA" },
	{ &IRQCount, 2, "IRQC" },
	{ &IRQLatch, 2, "IRQL" },
	{ 0 }
};

static void Sync(void) {
	setmirror(mirr);
	setprg8(0x8000, regs[0]);
	setprg8(0xA000, regs[1]);
	setprg8(0xC000, ~1);
	setprg8(0xE000, ~0);
	setchr2(0x0000, regs[2]);
	setchr2(0x0800, regs[3]);
	setchr1(0x1000, regs[4]);
	setchr1(0x1400, regs[5]);
	setchr1(0x1800, regs[6]);
	setchr1(0x1C00, regs[7]);
}

static DECLFW(M33Write) {
	A &= 0xF003;
	switch(A) {
	case 0x8000: regs[0] = V & 0x3F; if(!is48) mirr = ((V >> 6) & 1) ^ 1; Sync(); break;
	case 0x8001: regs[1] = V & 0x3F; Sync(); break;
	case 0x8002: regs[2] = V; Sync(); break;
	case 0x8003: regs[3] = V; Sync(); break;
	case 0xA000: regs[4] = V; Sync(); break;
	case 0xA001: regs[5] = V; Sync(); break;
	case 0xA002: regs[6] = V; Sync(); break;
	case 0xA003: regs[7] = V; Sync(); break;
	}
}

static DECLFW(M48Write) {
	switch (A & 0xF003) {
	case 0xC000: IRQLatch = V; break;
	case 0xC001: IRQCount = IRQLatch; break;
	case 0xC003: IRQa = 0; X6502_IRQEnd(FCEU_IQEXT); break;
	case 0xC002: IRQa = 1; break;
	case 0xE000: mirr = ((V >> 6) & 1) ^ 1; Sync(); break;
	}
}

static void M33Power(void) {
	Sync();
	SetReadHandler(0x8000, 0xFFFF, CartBR);
	SetWriteHandler(0x8000, 0xFFFF, M33Write);
}

static void M48Power(void) {
	Sync();
	SetReadHandler(0x8000, 0xFFFF, CartBR);
	SetWriteHandler(0x8000, 0xBFFF, M33Write);
	SetWriteHandler(0xC000, 0xFFFF, M48Write);
}

static void M48IRQ(void) {
	if (IRQa) {
		IRQCount++;
		if (IRQCount == 0x100) {
			X6502_IRQBegin(FCEU_IQEXT);
			IRQa = 0;
		}
	}
}

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

void Mapper33_Init(CartInfo *info) {
	is48 = 0;
	info->Power = M33Power;
	GameStateRestore = StateRestore;
	AddExState(&StateRegs, ~0, 0, 0);
}

void Mapper48_Init(CartInfo *info) {
	is48 = 1;
	info->Power = M48Power;
	GameHBIRQHook = M48IRQ;
	GameStateRestore = StateRestore;
	AddExState(&StateRegs, ~0, 0, 0);
}