fceugx/source/fceultra/boards/et-4320.cpp

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
*	Copyright (C) 2016 Cluster
*	http://clusterrr.com
*	clusterrr@clusterrr.com
*
* 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
*/

/*
MMC3-based multicart mapper with CHR RAM, CHR ROM and PRG RAM

$6000-7FFF:	A~[011xxxxx xxMRSBBB]	Multicart reg
This register can only be written to if PRG-RAM is enabled and writable (see $A001)
and BBB = 000 (power on state)

BBB = CHR+PRG block select bits (A19, A18, A17 for both PRG and CHR)
S = PRG block size & mirroring mode (0=128k with normal MMC3, 1=256k with TxSROM-like single-screen mirroring)
R = CHR mode (0=CHR ROM	 1=CHR RAM)
M = CHR block size (0=256k	 1=128k)
ignored when S is 0 for some reason

Example Game:
--------------------------
7 in 1 multicart (Amarello, TMNT2, Contra, Ninja Cat, Ninja Crusaders, Rainbow Islands 2)
*/

#include "mapinc.h"
#include "mmc3.h"

static uint8 *CHRRAM;
static uint32 CHRRAMSize;
static uint8 PPUCHRBus;
static uint8 TKSMIR[8];

static void BMC810131C_PW(uint32 A, uint8 V) {
	if ((EXPREGS[0] >> 3) & 1)
		setprg8(A, (V & 0x1F) | ((EXPREGS[0] & 7) << 4));
	else
		setprg8(A, (V & 0x0F) | ((EXPREGS[0] & 7) << 4));
}

static void BMC810131C_CW(uint32 A, uint8 V) {
	if ((EXPREGS[0] >> 4) & 1)
		setchr1r(0x10, A, V);
	else if (((EXPREGS[0] >> 5) & 1) && ((EXPREGS[0] >> 3) & 1))
		setchr1(A, V | ((EXPREGS[0] & 7) << 7));
	else
		setchr1(A, (V & 0x7F) | ((EXPREGS[0] & 7) << 7));

	TKSMIR[A >> 10] = V >> 7;
	if (((EXPREGS[0] >> 3) & 1) && (PPUCHRBus == (A >> 10)))
		setmirror(MI_0 + (V >> 7));
}

static DECLFW(BMC810131C_Write) {
	if (((A001B & 0xC0) == 0x80) && !(EXPREGS[0] & 7))
	{
		EXPREGS[0] = A & 0x3F;
		FixMMC3PRG(MMC3_cmd);
		FixMMC3CHR(MMC3_cmd);
	}
	else {
		CartBW(A, V);
	}
}

static void BMC810131C_Reset(void) {
	EXPREGS[0] = 0;
	MMC3RegReset();
}

static void BMC810131C_Power(void) {
	EXPREGS[0] = 0;
	GenMMC3Power();
	SetWriteHandler(0x6000, 0x7FFF, BMC810131C_Write);
}

static void BMC810131C_Close(void) {
	if (CHRRAM)
		FCEU_gfree(CHRRAM);
	CHRRAM = NULL;
}

static void TKSPPU(uint32 A) {
	A &= 0x1FFF;
	A >>= 10;
	PPUCHRBus = A;
	if ((EXPREGS[0] >> 3) & 1)
		setmirror(MI_0 + TKSMIR[A]);
}

void BMC810131C_Init(CartInfo *info) {
	GenMMC3_Init(info, 256, 256, 8, 0);
	CHRRAMSize = 8192;
	CHRRAM = (uint8*)FCEU_gmalloc(CHRRAMSize);
	SetupCartCHRMapping(0x10, CHRRAM, CHRRAMSize, 1);
	AddExState(CHRRAM, CHRRAMSize, 0, "CHRR");
	pwrap = BMC810131C_PW;
	cwrap = BMC810131C_CW;
	PPU_hook = TKSPPU;
	info->Power = BMC810131C_Power;
	info->Reset = BMC810131C_Reset;
	info->Close = BMC810131C_Close;
	AddExState(EXPREGS, 1, 0, "EXPR");
}