Files
ci-libretro-fceumm/src/boards/163.c
2022-02-12 16:13:05 +08:00

125 lines
3.2 KiB
C

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2002 Xodnizel
* Copyright (C) 2005 CaH4e3
* Copyright (C) 2019 Libretro Team
*
* 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
*/
/* Nanjing FC-001 PCB */
#include "mapinc.h"
static uint8 *WRAM;
static uint32 WRAMSIZE;
static uint8 reg[4];
static SFORMAT StateRegs[] =
{
{ reg, 4, "REGS" },
{ 0 }
};
static void sync()
{
setprg32(0x8000, reg[2] <<4 | reg[0] &0xF | (reg[3] &0x04? 0x00: 0x03));
setprg8r(0x10, 0x6000, 0);
if (~reg[0] &0x80)
setchr8(0);
}
static void hblank(void) {
if (reg[0] &0x80 && scanline <239)
{ /* Actual hardware cannot look at the current scanline number, but instead latches PA09 on PA13 rises. This does not seem possible with the current PPU emulation however. */
setchr4(0x0000, scanline >=127? 1: 0);
setchr4(0x1000, scanline >=127? 1: 0);
}
else
setchr8(0);
}
static DECLFR(readReg)
{
return ~reg[1] &0x04;
}
static DECLFW(writeReg)
{
uint8 index = A >>8 &3;
/* Swap bits of registers 0-2 again if the "swap bits" bit is set. Exclude register 2 on when PRG-ROM is 1 MiB. */
if (reg[3] &0x01 && index <= (ROM_size == 64? 1: 2))
V = V &~3 | V >>1 &1 | V <<1 &2;
if (A &1)
{
if (reg[1] &0x01 && ~V &0x01) reg[1] ^=0x04; /* If A0=1, flip feedback bit on falling edges of D0 */
} /* If A0=0, write to register */
else
reg[index] = V;
sync();
}
static void power(void)
{
memset(reg, 0, sizeof(reg));
sync();
SetReadHandler (0x5000, 0x57FF, readReg);
SetWriteHandler(0x5000, 0x57FF, writeReg);
SetReadHandler (0x6000, 0xFFFF, CartBR);
SetWriteHandler(0x6000, 0x7FFF, CartBW);
}
static void reset(void)
{
memset(reg, 0, sizeof(reg));
sync();
}
static void close(void)
{
if (WRAM)
FCEU_gfree(WRAM);
WRAM = NULL;
}
static void StateRestore(int version)
{
sync();
}
void Mapper163_Init (CartInfo *info)
{
info->Power = power;
info->Reset = reset;
info->Close = close;
GameHBIRQHook = hblank;
GameStateRestore = StateRestore;
AddExState(StateRegs, ~0, 0, 0);
WRAMSIZE = info->iNES2? (info->PRGRamSize + info->PRGRamSaveSize): 8192;
WRAM = (uint8*) FCEU_gmalloc(WRAMSIZE);
SetupCartPRGMapping(0x10, WRAM, WRAMSIZE, 1);
AddExState(WRAM, WRAMSIZE, 0, "WRAM");
FCEU_CheatAddRAM(WRAMSIZE >> 10, 0x6000, WRAM);
if (info->battery) {
info->SaveGame[0] = WRAM;
info->SaveGameLen[0] = WRAMSIZE;
}
}