fceux/src/boards/225.cpp

104 lines
2.4 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2011 CaH4e3
* Copyright (C) 2019 Libretro Team
* Copyright (C) 2020
*
* 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
*
* PCB-018 board, discrete multigame cart 110-in-1
*
* Mapper 225
* Mapper 255
*
*/
/* 2020-2-20 - merge mapper 255, re-implement extra RAM */
#include "mapinc.h"
static uint8 extraRAM[4], prg, mode, chr, mirr;
static SFORMAT StateRegs[] =
{
{ extraRAM, 4, "PROT" },
{ &prg, 1, "PRG" },
{ &chr, 1, "CHR" },
{ &mode, 1, "MODE" },
{ &mirr, 1, "MIRR" },
{ 0 }
};
static void Sync(void) {
if (mode) {
setprg16(0x8000, prg);
setprg16(0xC000, prg);
}
else
setprg32(0x8000, prg >> 1);
setchr8(chr);
setmirror(mirr ^ 1);
}
static DECLFW(M225Write) {
uint8 bank = (A >> 14) & 1;
mirr = (A >> 13) & 1;
mode = (A >> 12) & 1;
chr = (A & 0x3f) | (bank << 6);
prg = ((A >> 6) & 0x3f) | (bank << 6);
Sync();
}
static DECLFW(M225LoWrite) {
/* e.g. 115-in-1 [p1][!] CRC32 0xb39d30b4 */
if (A & 0x800) extraRAM[A & 3] = V & 0x0F;
}
static DECLFR(M225LoRead) {
if (A & 0x800) return extraRAM[A & 3];
return X.DB;
}
static void M225Power(void) {
prg = 0;
mode = 0;
Sync();
SetReadHandler(0x5000, 0x5fff, M225LoRead);
SetWriteHandler(0x5000, 0x5fff, M225LoWrite);
SetReadHandler(0x8000, 0xFFFF, CartBR);
SetWriteHandler(0x8000, 0xFFFF, M225Write);
}
static void M225Reset(void) {
prg = 0;
mode = 0;
Sync();
}
static void StateRestore(int version) {
Sync();
}
void Mapper225_Init(CartInfo *info) {
info->Reset = M225Reset;
info->Power = M225Power;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}
void Mapper255_Init(CartInfo *info) {
Mapper225_Init(info);
}