Files
ci-libretro-fceumm/src/boards/resettxrom.c
negativeExponent c42a1d8a8e Update
2022-02-20 06:46:45 +08:00

86 lines
2.5 KiB
C

/* FCEUmm - NES/Famicom Emulator
*
* Copyright notice for this file:
* 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
*/
/* NES 2.0 Mapper 313 is used for MMC3-based multicarts that switch
* between 128 KiB PRG-ROM/128 KiB CHR-ROM-sized games on each reset and
* thus require no additional registers.
* Its UNIF board name is BMC-RESET-TXROM.
*/
#include "mapinc.h"
#include "mmc3.h"
static uint8 submapper;
static void M313CW(uint32 A, uint8 V) {
/*FCEU_printf("CHR: A:%04x V:%02x 0:%02x\n", A, V, EXPREGS[0]);*/
uint32_t bank;
switch (submapper) {
default: bank = (EXPREGS[0] << 7) | (V & 0x7F); break;
case 1: bank = (EXPREGS[0] << 7) | (V & 0x7F); break;
case 2: bank = (EXPREGS[0] << 8) | (V & 0xFF); break;
case 3: bank = (EXPREGS[0] << 8) | (V & 0xFF); break;
case 4: bank = (EXPREGS[0] << 7) | (V & 0x7F); break;
}
setchr1(A, bank);
}
static void M313PW(uint32 A, uint8 V) {
/*FCEU_printf("PRG: A:%04x V:%02x 0:%02x\n", A, V, EXPREGS[0]);*/
uint32_t bank;
switch (submapper) {
default: bank = (EXPREGS[0] << 4) | (V & 0x0F); break;
case 1: bank = (EXPREGS[0] << 5) | (V & 0x1F); break;
case 2: bank = (EXPREGS[0] << 4) | (V & 0x0F); break;
case 3: bank = (EXPREGS[0] << 5) | (V & 0x1F); break;
case 4:
if (EXPREGS[0] == 0)
bank = (EXPREGS[0] << 5) | (V & 0x1F);
else
bank = (EXPREGS[0] << 4) | (V & 0x0F);
break;
}
setprg8(A, bank);
}
static void M313Reset(void) {
EXPREGS[0]++;
EXPREGS[0] &= 0x03;
MMC3RegReset();
}
static void M313Power(void) {
EXPREGS[0] = 0;
GenMMC3Power();
}
/* NES 2.0 313, UNIF BMC-RESET-TXROM */
void BMCRESETTXROM_Init(CartInfo *info) {
GenMMC3_Init(info, 256, 256, 8, 0);
cwrap = M313CW;
pwrap = M313PW;
submapper = info->submapper;
info->Power = M313Power;
info->Reset = M313Reset;
AddExState(&EXPREGS[0], 1, 0, "EXPR");
AddExState(&submapper, 1, 0, "SUBM");
}