Files
ci-libretro-fceumm/src/boards/182.c
2025-09-12 21:59:27 +02:00

76 lines
2.1 KiB
C

/* FCEUmm - NES/Famicom Emulator
*
* Copyright notice for this file:
* 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
*
*
*/
#include "mapinc.h"
#include "asic_mmc3.h"
static uint8 reg[4];
static void sync () {
int prgAND = reg[1] &0x20? 0x1F: 0x0F;
int chrAND = reg[1] &0x40? 0xFF: 0x7F;
int prgOR = (reg[1] &0x02? 0x10: 0x00) | (reg[1] &0x10? 0x020: 0x00);
int chrOR = (reg[1] &0x02? 0x80: 0x00) | (reg[1] &0x10? 0x100: 0x00);
if (reg[0] &0x80) {
if (reg[0] &0x20)
setprg32(0x8000, reg[0] >>1);
else {
setprg16(0x8000, reg[0]);
setprg16(0xC000, reg[0]);
}
} else
MMC3_syncPRG(prgAND, prgOR &~prgAND);
MMC3_syncCHR(chrAND, chrOR &~chrAND);
MMC3_syncMirror();
}
static DECLFW (writeReg) {
if (~reg[1] &0x01) {
reg[A &3] = V;
sync();
}
}
static DECLFW (unscramble) {
static const uint16 lutAddress[8] = { 0xA001, 0xA000, 0x8000, 0xC000, 0x8001, 0xC001, 0xE000, 0xE001 }; /* i <5? 4-i: i */
static const uint8 lutIndex[8] = { 0, 3, 1, 5, 6, 7, 2, 4 }; /* i <6? (i^3)-1: i */
MMC3_writeReg(lutAddress[A >>12 &6 | A &1], (A &0xE001) == 0xA000? lutIndex[V &7]: V);
}
static void reset () {
reg[0] = reg[1] = reg[2] = reg[3] = 0;
MMC3_clear();
}
static void power () {
reg[0] = reg[1] = reg[2] = reg[3] = 0;
MMC3_power();
SetWriteHandler(0x8000, 0xFFFF, unscramble);
}
void Mapper182_Init (CartInfo *info) {
MMC3_init(info, sync, MMC3_TYPE_AX5202P, NULL, NULL, NULL, writeReg);
info->Power = power;
info->Reset = reset;
AddExState(reg, 4, 0, "EXPR");
}